packages feed

balkon (empty) → 0.1.0.0

raw patch · 36 files changed

+3255/−0 lines, 36 filesdep +balkondep +basedep +bytestringbinary-added

Dependencies added: balkon, base, bytestring, filepath, harfbuzz-pure, hspec, hspec-discover, hspec-golden, text, text-icu, unicode-data-scripts

Files

+ CHANGELOG.md view
@@ -0,0 +1,20 @@+# Revision history for Balkón++## 1.0.0.0 -- 2023-03-13++* Text shaping using HarfBuzz.++* Breaking text on line and character boundaries using the International+  Components for Unicode (ICU) library.++* Trimming white space at the end of lines.++* Calculation of containing block bounds and fragment bounds.++* Support for plain text (single font and line height) in one horizontal+  direction (LTR or RTL).++* Input can be divided into spans. This division will be preserved in the+  output.++* Each span can use a different language for text shaping and line breaking.
+ LICENSE view
@@ -0,0 +1,674 @@+              GNU GENERAL PUBLIC LICENSE+                Version 3, 29 June 2007++ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.++                     Preamble++  The GNU General Public License is a free, copyleft license for+software and other kinds of works.++  The licenses for most software and other practical works are designed+to take away your freedom to share and change the works.  By contrast,+the GNU General Public License is intended to guarantee your freedom to+share and change all versions of a program--to make sure it remains free+software for all its users.  We, the Free Software Foundation, use the+GNU General Public License for most of our software; it applies also to+any other work released this way by its authors.  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+ assets/fonts/plex/IBMPlexSansArabic-Regular.ttf view

binary file changed (absent → 226004 bytes)

+ assets/fonts/plex/OFL.txt view
@@ -0,0 +1,93 @@+Copyright © 2017 IBM Corp. with Reserved Font Name "Plex"
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.
+ assets/fonts/ubuntu/LICENCE.txt view
@@ -0,0 +1,96 @@+-------------------------------+UBUNTU FONT LICENCE Version 1.0+-------------------------------++PREAMBLE+This licence allows the licensed fonts to be used, studied, modified and+redistributed freely. The fonts, including any derivative works, can be+bundled, embedded, and redistributed provided the terms of this licence+are met. The fonts and derivatives, however, cannot be released under+any other licence. The requirement for fonts to remain under this+licence does not require any document created using the fonts or their+derivatives to be published under this licence, as long as the primary+purpose of the document is not to be a vehicle for the distribution of+the fonts.++DEFINITIONS+"Font Software" refers to the set of files released by the Copyright+Holder(s) under this licence and clearly marked as such. This may+include source files, build scripts and documentation.++"Original Version" refers to the collection of Font Software components+as received under this licence.++"Modified Version" refers to any derivative made by adding to, deleting,+or substituting -- in part or in whole -- any of the components of the+Original Version, by changing formats or by porting the Font Software to+a new environment.++"Copyright Holder(s)" refers to all individuals and companies who have a+copyright ownership of the Font Software.++"Substantially Changed" refers to Modified Versions which can be easily+identified as dissimilar to the Font Software by users of the Font+Software comparing the Original Version with the Modified Version.++To "Propagate" a work means to do anything with it that, without+permission, would make you directly or secondarily liable for+infringement under applicable copyright law, except executing it on a+computer or modifying a private copy. Propagation includes copying,+distribution (with or without modification and with or without charging+a redistribution fee), making available to the public, and in some+countries other activities as well.++PERMISSION & CONDITIONS+This licence does not grant any rights under trademark law and all such+rights are reserved.++Permission is hereby granted, free of charge, to any person obtaining a+copy of the Font Software, to propagate the Font Software, subject to+the below conditions:++1) Each copy of the Font Software must contain the above copyright+notice and this licence. These can be included either as stand-alone+text files, human-readable headers or in the appropriate machine-+readable metadata fields within text or binary files as long as those+fields can be easily viewed by the user.++2) The font name complies with the following:+(a) The Original Version must retain its name, unmodified.+(b) Modified Versions which are Substantially Changed must be renamed to+avoid use of the name of the Original Version or similar names entirely.+(c) Modified Versions which are not Substantially Changed must be+renamed to both (i) retain the name of the Original Version and (ii) add+additional naming elements to distinguish the Modified Version from the+Original Version. The name of such Modified Versions must be the name of+the Original Version, with "derivative X" where X represents the name of+the new work, appended to that name.++3) The name(s) of the Copyright Holder(s) and any contributor to the+Font Software shall not be used to promote, endorse or advertise any+Modified Version, except (i) as required by this licence, (ii) to+acknowledge the contribution(s) of the Copyright Holder(s) or (iii) with+their explicit written permission.++4) The Font Software, modified or unmodified, in part or in whole, must+be distributed entirely under this licence, and must not be distributed+under any other licence. The requirement for fonts to remain under this+licence does not affect any document created using the Font Software,+except any version of the Font Software extracted from a document+created using the Font Software may only be distributed under this+licence.++TERMINATION+This licence becomes null and void if any of the above conditions are+not met.++DISCLAIMER+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF+COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM OTHER+DEALINGS IN THE FONT SOFTWARE.
+ assets/fonts/ubuntu/TRADEMARKS.txt view
@@ -0,0 +1,4 @@+Ubuntu and Canonical are registered trademarks of Canonical Ltd.++The licence accompanying these works does not grant any rights+under trademark law and all such rights are reserved.
+ assets/fonts/ubuntu/Ubuntu-R.ttf view

binary file changed (absent → 353824 bytes)

+ assets/fonts/ubuntu/copyright.txt view
@@ -0,0 +1,5 @@+Copyright 2010,2011 Canonical Ltd.++This Font Software is licensed under the Ubuntu Font Licence, Version+1.0.  https://launchpad.net/ubuntu-font-licence+
+ balkon.cabal view
@@ -0,0 +1,176 @@+cabal-version:      2.4++-- Initial package description 'balkon.cabal' generated by+-- 'cabal init'. For further documentation, see:+--   http://haskell.org/cabal/users-guide/+--+-- The name of the package.+name:               balkon++-- The package version.+-- See the Haskell package versioning policy (PVP) for standards+-- guiding when and how versions should be incremented.+-- https://pvp.haskell.org+-- PVP summary:     +-+------- breaking API changes+--                  | | +----- non-breaking API additions+--                  | | | +--- code changes with no API change+version:            0.1.0.0++stability:          experimental++-- A short (one-line) description of the package.+synopsis:           Text layout engine built on top of HarfBuzz.++-- A longer description of the package.+description:+    .+    Given an input text and formatting options, Balkón produces an inline+    layout with defined glyph positions and box coordinates, all within a+    containing unit called a paragraph.+    .+    Internally, HarfBuzz is used to shape individual runs of text, each of+    which fits within one line and has a constant script, direction, language,+    and formatting. Balkón abstracts this so that you can provide text with any+    mix of these attributes and a desired line width for line breaking.++-- URL for the project homepage or repository.+homepage:           https://argonaut-constellation.org/++-- A URL where users can report bugs.+bug-reports:        https://todo.argonaut-constellation.org/~jaro/balkon++-- The license under which the package is released.+license:            GPL-3.0-only++-- The file containing the license text.+license-file:       LICENSE++-- The package author(s).+author:             Jaro++-- An email address to which users can send suggestions, bug reports,+-- and patches.+maintainer:         jaro@argonaut-constellation.org++-- A copyright notice.+-- copyright:++category:           Text++-- Extra doc files to be distributed with the package, such as a CHANGELOG+-- or a README.+extra-doc-files:    CHANGELOG.md++-- Extra source files to be distributed with the package, such as examples,+-- or a tutorial module.+extra-source-files:+    assets/fonts/plex/IBMPlexSansArabic-Regular.ttf,+    assets/fonts/plex/OFL.txt,+    assets/fonts/ubuntu/LICENCE.txt,+    assets/fonts/ubuntu/TRADEMARKS.txt,+    assets/fonts/ubuntu/Ubuntu-R.ttf,+    assets/fonts/ubuntu/copyright.txt++source-repository head+    type:             git+    location:         https://git.argonaut-constellation.org/~jaro/balkon+    branch:           main++common language+    -- Base language which the package is written in.+    default-language: Haskell2010+    -- LANGUAGE extensions used by modules in this package.+    -- other-extensions:++common warnings+    ghc-options:      -Wall++library balkon-internal+    import:           language, warnings++    -- Directories containing source files of the internal library.+    hs-source-dirs:   src++    -- Modules exported to tests and to the public part of the library.+    exposed-modules:+        Data.Text.ParagraphLayout.Internal.Break,+        Data.Text.ParagraphLayout.Internal.Fragment,+        Data.Text.ParagraphLayout.Internal.LineHeight,+        Data.Text.ParagraphLayout.Internal.Paragraph,+        Data.Text.ParagraphLayout.Internal.ParagraphConstruction,+        Data.Text.ParagraphLayout.Internal.Plain,+        Data.Text.ParagraphLayout.Internal.Rect,+        Data.Text.ParagraphLayout.Internal.ResolvedSpan,+        Data.Text.ParagraphLayout.Internal.Run,+        Data.Text.ParagraphLayout.Internal.Script,+        Data.Text.ParagraphLayout.Internal.Span,+        Data.Text.ParagraphLayout.Internal.TextContainer,+        Data.Text.ParagraphLayout.Internal.Zipper++    -- Modules used purely internally and not in any tests.+    other-modules:+        Data.Text.ParagraphLayout.Internal.ProtoFragment++    build-depends:+        base >=4.12 && < 4.16,+        harfbuzz-pure >=1.0.2.0 && <1.1,+        text >=2.0.2 && <3,+        text-icu >=0.8.0.2 && <0.9,+        unicode-data-scripts >=0.2.0.1 && < 0.3++library+    import:           language, warnings++    -- Directories containing source files.+    hs-source-dirs:   lib++    -- Modules exported by the library.+    exposed-modules:+        Data.Text.ParagraphLayout,+        Data.Text.ParagraphLayout.ParagraphConstruction,+        Data.Text.ParagraphLayout.Rect++    -- Other library packages from which modules are imported.+    build-depends:+        base >=4.12 && <4.16,+        balkon-internal++test-suite balkon-test+    import:           language, warnings++    -- The interface type and version of the test suite.+    type:             exitcode-stdio-1.0++    -- Directories containing source files.+    hs-source-dirs:   test++    -- The entrypoint to the test suite.+    main-is:          Spec.hs++    other-modules:+        Data.Text.ParagraphLayoutSpec,+        Data.Text.ParagraphLayout.FontLoader,+        Data.Text.ParagraphLayout.Internal.BreakSpec,+        Data.Text.ParagraphLayout.Internal.RunSpec,+        Data.Text.ParagraphLayout.Internal.TextContainerSpec,+        Data.Text.ParagraphLayout.Internal.ZipperSpec,+        Data.Text.ParagraphLayout.ParagraphData,+        Data.Text.ParagraphLayout.RectSpec,+        Data.Text.ParagraphLayout.SpanData++    -- Test dependencies.+    build-depends:+        base,+        balkon,+        balkon-internal,+        bytestring >=0.11.4 && < 0.12,+        filepath >=1.4.2.1 && < 1.5,+        harfbuzz-pure,+        hspec >=2.10.9 && <2.11,+        hspec-discover >=2.10.9 && <2.11,+        hspec-golden >=0.2.0.1 && <0.3,+        text,+        text-icu++    build-tool-depends:+        hspec-discover:hspec-discover
+ lib/Data/Text/ParagraphLayout.hs view
@@ -0,0 +1,37 @@+-- |+--+-- Positions and distances are represented as 32-bit integers. Their unit must+-- be defined by the caller, who must calculate the desired dimensions of the+-- EM square of the input font and set them using+-- `Data.Text.Glyphize.optionScale`.+--+-- For example, if @1em = 20px@, if the output pixels are square, and if the+-- output coordinates are in 1/64ths of a pixel, you should set the scale to+-- @`Just` (1280, 1280)@.+--+-- X coordinates increase from left to right.+--+-- Y coordinates increase from bottom to top.+module Data.Text.ParagraphLayout+    (Fragment(Fragment, fragmentPen, fragmentRect, fragmentGlyphs)+    ,LineHeight(Absolute, Normal)+    ,Paragraph(Paragraph)+    ,ParagraphLayout(ParagraphLayout, paragraphRect, spanLayouts)+    ,ParagraphOptions+        (ParagraphOptions+        ,paragraphFont+        ,paragraphLineHeight+        ,paragraphMaxWidth+        )+    ,Span(Span, spanLength, spanOptions)+    ,SpanLayout(SpanLayout)+    ,SpanOptions(SpanOptions, spanLanguage)+    ,layoutPlain+    )+where++import Data.Text.ParagraphLayout.Internal.Fragment+import Data.Text.ParagraphLayout.Internal.LineHeight+import Data.Text.ParagraphLayout.Internal.Paragraph+import Data.Text.ParagraphLayout.Internal.Plain+import Data.Text.ParagraphLayout.Internal.Span
+ lib/Data/Text/ParagraphLayout/ParagraphConstruction.hs view
@@ -0,0 +1,18 @@+-- | Infix operators for construction of paragraphs with readable code.+--+-- Example construction:+-- @en = (,) SpanOptions { spanLanguage = "en" }@+-- @ja = (,) SpanOptions { spanLanguage = "ja" }@+-- @"ignored prefix" |\< en "one two " \>|\< ja "三四" \>| "ignored suffix"@+--+-- Special syntax for paragraphs with no contents:+-- @"ignored prefix" |<>| "ignored suffix"@+module Data.Text.ParagraphLayout.ParagraphConstruction+    ((>|)+    ,(>|<)+    ,(|<)+    ,(|<>|)+    )+where++import Data.Text.ParagraphLayout.Internal.ParagraphConstruction
+ lib/Data/Text/ParagraphLayout/Rect.hs view
@@ -0,0 +1,16 @@+-- | Representation of an axis-aligned rectangle on a 2D plane, with one of its+-- corners being a designated origin point.+module Data.Text.ParagraphLayout.Rect+    (Rect(Rect, x_origin, y_origin, x_size, y_size)+    ,height+    ,width+    ,x_max+    ,x_min+    ,x_terminus+    ,y_max+    ,y_min+    ,y_terminus+    )+where++import Data.Text.ParagraphLayout.Internal.Rect
+ src/Data/Text/ParagraphLayout/Internal/Break.hs view
@@ -0,0 +1,39 @@+-- | Boundary analysis using `Data.Text.ICU`, but returning numeric offsets+-- instead of text slices.+--+-- Within this module, each /offset/ refers to the number of `Data.Word.Word8`+-- items (also called UTF-8 code units or bytes) between the start of the input+-- `Text` and the position of the break. The internal offset of the `Text` from+-- the start of its underlying byte array is excluded.+module Data.Text.ParagraphLayout.Internal.Break (breaksDesc, subOffsetsDesc)+where++import Data.Text (Text)+import Data.Text.Foreign (lengthWord8)+import Data.Text.ICU (Break, Breaker, breaksRight, brkPrefix, brkStatus)++-- | List of all breaks in the given text, with offsets in descending order,+-- including the status of the break if applicable.+--+-- Includes the start of the text (with offset 0) as the last list item.+--+-- Excludes the end of the text (with offset equal to the text length).+breaksDesc :: Breaker a -> Text -> [(Int, a)]+breaksDesc breaker input = map brkStartOffsetStatus $ breaksRight breaker input++brkStartOffsetStatus :: Break a -> (Int, a)+brkStartOffsetStatus brk = (brkStartOffset brk, brkStatus brk)++-- | The ICU library returns "breaks" as slices of text with two boundaries.+-- This gives the smaller of the two distances from the start of the text+-- to the boundaries of the break.+brkStartOffset :: Break a -> Int+brkStartOffset brk = lengthWord8 (brkPrefix brk)++-- | Given a list of offsets into a text in descending order, produce a list of+-- corresponding offsets into a slice of the text starting at a given offset.+subOffsetsDesc :: Int -> [(Int, a)] -> [(Int, a)]+subOffsetsDesc d = takeWhile valid . map adjust+    where+        valid (off, _) = off >= 0+        adjust (off, a) = (off - d, a)
+ src/Data/Text/ParagraphLayout/Internal/Fragment.hs view
@@ -0,0 +1,43 @@+module Data.Text.ParagraphLayout.Internal.Fragment (Fragment(..))+where++import Data.Int (Int32)+import Data.Text.Glyphize (GlyphInfo, GlyphPos)++import Data.Text.ParagraphLayout.Internal.Rect++-- | A unit of text laid out in a rectangular area.+--+-- Equivalent to the CSS3 terms /box fragment/ or /fragment/, except that+-- continuous text even within one line can be split into multiple fragments,+-- either because it comes from multiple input spans, or because it contains+-- glyphs from multiple scripts.+data Fragment = Fragment++    { fragmentRect :: Rect Int32+    -- ^ Physical position of the fragment within the paragraph, calculated+    -- using all glyph advances in this fragment and the calculated line height.+    --+    -- This is the space that the glyphs "take up" and is probably what you+    -- want to use for detecting position-based events such as mouse clicks.+    --+    -- Beware that actual glyphs will not be drawn exactly to the borders of+    -- this rectangle – they may be offset inwards and they can also extend+    -- outwards!+    --+    -- These are not the typographic bounding boxes that you use for determining+    -- the area to draw on – you need FreeType or a similar library for that.+    --+    -- The origin coordinates are relative to the paragraph.++    , fragmentPen :: (Int32, Int32)+    -- ^ Coordinates of the initial pen position, from which the first glyph+    -- should be drawn, relative to the origin of the `fragmentRect`.+    -- Each glyph's `x_advance` or `y_advance` are then used to move the pen+    -- position for the next glyph.++    , fragmentGlyphs :: [(GlyphInfo, GlyphPos)]+    -- ^ Glyphs contained in the fragment, as returned from HarfBuzz.++    }+    deriving (Eq, Read, Show)
+ src/Data/Text/ParagraphLayout/Internal/LineHeight.hs view
@@ -0,0 +1,15 @@+module Data.Text.ParagraphLayout.Internal.LineHeight (LineHeight(..))+where++import Data.Int (Int32)++data LineHeight++    = Normal+    -- ^ Determine the preferred line height automatically using its ascent and+    -- descent metrics.++    | Absolute Int32+    -- ^ Set the preferred line height independently of the font.++    deriving (Eq, Read, Show)
+ src/Data/Text/ParagraphLayout/Internal/Paragraph.hs view
@@ -0,0 +1,117 @@+module Data.Text.ParagraphLayout.Internal.Paragraph+    (Paragraph(..)+    ,ParagraphLayout(..)+    ,ParagraphOptions(..)+    ,paragraphLayout+    ,paragraphOriginX+    ,paragraphOriginY+    ,paragraphSpanBounds+    )+where++import Data.Int (Int32)+import Data.List.NonEmpty (NonEmpty)+import qualified Data.List.NonEmpty as NonEmpty+import Data.Text.Array (Array)+import Data.Text.Glyphize (Font)++import Data.Text.ParagraphLayout.Internal.LineHeight+import Data.Text.ParagraphLayout.Internal.Rect+import Data.Text.ParagraphLayout.Internal.Span++-- | Text to be laid out as a single paragraph.+--+-- May be divided into any number of neighbouring spans, each of which will+-- be represented as a separate `SpanLayout` in the resulting layout.+--+-- The input text must be encoded as UTF-8 in a contiguous byte array.+--+-- You may need to use "Data.Text.Internal" in order to determine the byte+-- array and the necessary offsets to construct the paragraph without copying+-- data.+--+-- For simple use cases, it may be sufficient to construct paragraphs using+-- [ParagraphConstruction]("Data.Text.ParagraphLayout.ParagraphConstruction").+data Paragraph = Paragraph++    Array+    -- ^ A byte array containing the whole text to be laid out, in UTF-8.+    --+    -- This array will be passed to "Data.Text.Glyphize", which passes it to+    -- [@hb_buffer_add_utf8()@]+    -- (https://harfbuzz.github.io/harfbuzz-hb-buffer.html#hb-buffer-add-utf8).+    --+    -- In the output, `Data.Text.Glyphize.cluster` will be a byte offset of+    -- the corresponding input character from this array.++    Int+    -- ^ Byte offset of the first span from the start of the byte array.+    -- Any characters preceding this offset will not be shaped, but may still+    -- be used to influence the shape of neighbouring characters.++    [Span]+    -- ^ Parts of the text to be laid out, in logical order.+    -- The initial offset plus total length of all spans must not exceed+    -- the bounds of the byte array.+    -- Any characters following the last span will not be shaped, but may still+    -- be used to influence the shape of neighbouring characters.++    ParagraphOptions+    -- ^ Options applying to the paragraph as a whole.++data ParagraphOptions = ParagraphOptions++    { paragraphFont :: Font+    -- ^ Font to be used for shaping and measurement.+    -- Make sure to set its scale (see `Data.Text.Glyphize.optionScale`) using+    -- the same units that you want in the output.++    , paragraphLineHeight :: LineHeight+    -- ^ Preferred line height of the resulting box fragments.++    , paragraphMaxWidth :: Int32+    -- ^ Line width at which line breaking should occur.+    -- Lines will be broken at language-appropriate boundaries.+    -- If a line still exceeds this limit then, it will be broken at character+    -- boundaries, and if it already consists of a single cluster that cannot+    -- be further broken down, it will overflow.++    }+    deriving (Eq, Show)++-- | The resulting layout of the whole paragraph.+data ParagraphLayout = ParagraphLayout+    { paragraphRect :: Rect Int32+    -- ^ The containing block (CSS3).+    , spanLayouts :: [SpanLayout]+    }+    deriving (Eq, Read, Show)++-- | Calculate the offsets into the `Paragraph`'s underlying `Array` where each+-- span starts and ends, in ascending order. The resulting list will be one+-- larger than the list of input spans.+paragraphSpanBounds :: Paragraph -> NonEmpty Int+paragraphSpanBounds (Paragraph _ initialOffset spans _) =+    NonEmpty.scanl (+) initialOffset (map spanLength spans)++paragraphOriginX :: (Num a) => a+paragraphOriginX = 0++paragraphOriginY :: (Num a) => a+paragraphOriginY = 0++empty :: (Num a) => Rect a+empty = Rect+    { x_origin = paragraphOriginX+    , y_origin = paragraphOriginY+    , x_size = 0+    , y_size = 0+    }++containRects :: (Ord a, Num a) => [Rect a] -> Rect a+containRects = foldr union empty++-- | Wrap the given `SpanLayout`s and compute their containing rectangle.+paragraphLayout :: [SpanLayout] -> ParagraphLayout+paragraphLayout sls = ParagraphLayout pRect sls+    where pRect = containRects $ concat $ map spanRects sls
+ src/Data/Text/ParagraphLayout/Internal/ParagraphConstruction.hs view
@@ -0,0 +1,54 @@+module Data.Text.ParagraphLayout.Internal.ParagraphConstruction+    ((>|)+    ,(>|<)+    ,(|<)+    ,(|<>|)+    )+where++import Data.Text (pack)+import Data.Text.Foreign (lengthWord8)+import Data.Text.Internal (Text(Text))+import Data.Text.Internal.Lazy (chunk, empty)+import qualified Data.Text.Internal.Lazy as Lazy+import Data.Text.Lazy (toStrict)+import Data.Text.ParagraphLayout.Internal.Plain+    (Paragraph(Paragraph)+    ,ParagraphOptions+    )+import Data.Text.ParagraphLayout.Internal.Span (Span(Span), SpanOptions)++-- | Create first span with optional ignored suffix.+infixr 5 >|+(>|) :: (SpanOptions, String) -> String -> (Lazy.Text, [Span])+(spanLanguage, spanText) >| suffix = (newText, newSpans)+    where+        newSpans = [newSpan]+        newSpan = Span (lengthWord8 packedSpanText) spanLanguage+        newText = chunk packedSpanText (chunk packedSuffix empty)+        packedSpanText = pack spanText+        packedSuffix = pack suffix++-- | Create next span.+infixr 5 >|<+(>|<) :: (SpanOptions, String) -> (Lazy.Text, [Span]) -> (Lazy.Text, [Span])+(spanLanguage, spanText) >|< (oldText, oldSpans) = (newText, newSpans)+    where+        newSpans = newSpan:oldSpans+        newSpan = Span (lengthWord8 packedSpanText) spanLanguage+        newText = chunk packedSpanText oldText+        packedSpanText = pack spanText++-- | Add optional ignored prefix and wrap in a `Paragraph`.+infixr 5 |<+(|<) :: String -> (Lazy.Text, [Span]) -> ParagraphOptions -> Paragraph+prefix |< (oldText, spans) = Paragraph arr afterPrefix spans+    where+        (Text arr beforePrefix _) = toStrict $ chunk packedPrefix oldText+        afterPrefix = beforePrefix + lengthWord8 packedPrefix+        packedPrefix = pack prefix++-- | Create a `Paragraph` with no spans, just two ignored texts.+infixr 5 |<>|+(|<>|) :: String -> String -> ParagraphOptions -> Paragraph+prefix |<>| suffix = prefix |< (chunk (pack suffix) empty, [])
+ src/Data/Text/ParagraphLayout/Internal/Plain.hs view
@@ -0,0 +1,269 @@+module Data.Text.ParagraphLayout.Internal.Plain+    (Paragraph(..)+    ,ParagraphLayout(..)+    ,ParagraphOptions(..)+    ,SpanLayout(..)+    ,layoutPlain+    )+where++import Control.Applicative (ZipList(ZipList), getZipList)+import Data.Int (Int32)+import Data.List (mapAccumL)+import Data.List.NonEmpty (NonEmpty((:|)))+import qualified Data.List.NonEmpty as NonEmpty+import Data.Text.Foreign (lengthWord8)+import Data.Text.Glyphize+    (Buffer(..)+    ,ContentType(ContentTypeUnicode)+    ,Direction(..)+    ,FontExtents(..)+    ,GlyphInfo+    ,GlyphPos+    ,defaultBuffer+    ,fontExtentsForDir+    ,shape+    )+import Data.Text.ICU (Breaker, LocaleName(Locale), breakCharacter, breakLine)+import qualified Data.Text.ICU as BreakStatus (Line)+import Data.Text.Internal (Text(Text))+import qualified Data.Text.Lazy as Lazy++import Data.Text.ParagraphLayout.Internal.Break+import Data.Text.ParagraphLayout.Internal.Fragment+import Data.Text.ParagraphLayout.Internal.LineHeight+import Data.Text.ParagraphLayout.Internal.Paragraph+import qualified Data.Text.ParagraphLayout.Internal.ProtoFragment as PF+import Data.Text.ParagraphLayout.Internal.Rect+import Data.Text.ParagraphLayout.Internal.ResolvedSpan (WithSpan(WithSpan))+import qualified Data.Text.ParagraphLayout.Internal.ResolvedSpan as RS+import Data.Text.ParagraphLayout.Internal.Run+import Data.Text.ParagraphLayout.Internal.Span+import Data.Text.ParagraphLayout.Internal.TextContainer++-- | Lay out a paragraph of plain, unidirectional text using a single font.+layoutPlain :: Paragraph -> ParagraphLayout+layoutPlain p@(Paragraph _ _ _ opts) = paragraphLayout sls+    where+        sls = map SpanLayout fragsBySpan+        fragsBySpan = take (length spans) $ RS.splitBySpanIndex frags+        frags = layoutAndAlignLines maxWidth $ spansToRunsWrapped spans+        maxWidth = paragraphMaxWidth opts+        spans = resolveSpans p++-- | Split a number of spans into a flat array of runs and add a wrapper+-- so that each run can be traced back to its originating span.+spansToRunsWrapped :: [RS.ResolvedSpan] -> [WithSpan Run]+spansToRunsWrapped ss = concat $ map spanToRunsWrapped ss++-- | Split a span into runs and add a wrapper+-- so that each run can be traced back to its originating span.+spanToRunsWrapped :: RS.ResolvedSpan -> [WithSpan Run]+spanToRunsWrapped s = map (WithSpan s) (spanToRuns s)++-- | Create a multi-line layout from the given runs, splitting them as+-- necessary to fit within the requested line width.+--+-- The output is a flat list of fragments positioned in both dimensions.+layoutAndAlignLines :: Int32 -> [WithSpan Run] -> [WithSpan Fragment]+layoutAndAlignLines maxWidth runs = frags+    where+        frags = concat fragsInLines+        (_, fragsInLines) = mapAccumL positionLineH originY canonicalLines+        canonicalLines = map canonicalOrder logicalLines+        logicalLines = layoutLines maxWidth runs+        originY = paragraphOriginY++-- | Reorder the given fragments from logical order to whatever order HarfBuzz+-- uses (LTR for horizontal text, TTB for vertical text), so that cluster order+-- is preserved even across runs.+canonicalOrder :: [WithSpan PF.ProtoFragment] -> [WithSpan PF.ProtoFragment]+canonicalOrder [] = []+canonicalOrder pfs@((WithSpan _ headPF):_) = case PF.direction headPF of+    -- TODO: Update for bidi.+    Just DirLTR -> pfs+    Just DirRTL -> reverse pfs+    Just DirTTB -> pfs+    Just DirBTT -> reverse pfs+    -- If no guess can be made, use LTR.+    -- TODO: Add explicit direction to input interface.+    Nothing -> pfs++-- | Create a multi-line layout from the given runs, splitting them as+-- necessary to fit within the requested line width.+--+-- The output is a two-dimensional list of fragments positioned along the+-- horizontal axis.+layoutLines :: Int32 -> [WithSpan Run] -> [[WithSpan PF.ProtoFragment]]+layoutLines maxWidth runs+    | null rest+        -- Everything fits. We are done.+        = fitting : []+    | otherwise+        -- Something fits, the rest goes on the next line.+        = fitting : layoutLines maxWidth rest+    where+        (fitting, rest) = layoutAndWrapRunsH maxWidth runs++-- TODO: Allow a run across multiple spans (e.g. if they only differ by colour).++-- | Position all the given horizontal fragments on the same line,+-- using `originY` as its top edge, and return the bottom edge for continuation.+--+-- Glyphs will be aligned by their ascent line, similar to the behaviour of+-- @vertical-align: top@ in CSS.+--+-- TODO: For rich text, allow other types of vertical alignment.+positionLineH :: Int32 -> [WithSpan PF.ProtoFragment] ->+    (Int32, [WithSpan Fragment])+positionLineH originY pfs = (nextY, frags)+    where+        -- A line with no glyphs will be considered to have zero height.+        -- This can happen when line breaking produces a line that contains+        -- onls spaces.+        nextY = if null rects then originY else maximum $ map y_min rects+        rects = map (\(WithSpan _ r) -> fragmentRect r) frags+        frags = snd $ mapAccumL (positionFragmentH originY) originX pfs+        originX = paragraphOriginX++-- | Position the given horizontal fragment on a line,+-- using `originY` as its top edge and `originX` as its left edge,+-- returning the X coordinate of its right edge for continuation.+positionFragmentH ::+    Int32 -> Int32 -> WithSpan PF.ProtoFragment -> (Int32, WithSpan Fragment)+positionFragmentH originY originX (WithSpan rs pf) = (nextX, WithSpan rs frag)+    where+        nextX = originX + PF.advance pf+        frag = Fragment rect (penX, penY) (PF.glyphs pf)+        rect = Rect originX originY (PF.advance pf) (-lineHeight)+        penX = 0+        penY = descent + leading `div` 2 - lineHeight+        lineHeight = case RS.spanLineHeight rs of+            Normal -> normalLineHeight+            Absolute h -> h+        leading = lineHeight - normalLineHeight+        normalLineHeight = ascent + descent+        ascent = ascender extents+        descent = - descender extents+        extents = fontExtentsForDir font (PF.direction pf)+        font = RS.spanFont rs++-- | Calculate layout for multiple horizontal runs, breaking them as necessary+-- to fit as much content as possible without exceeding the maximum line width,+-- and return the remaining runs to be placed on other lines.+layoutAndWrapRunsH :: Int32 -> [WithSpan Run] ->+    ([WithSpan PF.ProtoFragment], [WithSpan Run])+layoutAndWrapRunsH maxWidth runs = NonEmpty.head $ validLayouts+    where+        validLayouts = dropWhile1 tooLong layouts+        tooLong (pfs, _) = totalAdvances pfs > maxWidth+        layouts = NonEmpty.map layoutFst splits+        layoutFst (runs1, runs2) = (layout runs1, runs2)+        layout runs1 = layoutRunsH $ trimTextsEnd isEndSpace runs1+        splits = noSplit :| (lSplits ++ cSplits)+        noSplit = (runs, [])+        -- TODO: Use Soft/Hard line break distinction.+        lSplits = splitTextsBy (map fst . runLineBreaks) runs+        cSplits = splitTextsBy (map fst . runCharacterBreaks) runs++-- | The suffix remaining after removing the longest prefix of the list for+-- which the predicate holds, except always including at least the last element+-- of the original list.+dropWhile1 :: (a -> Bool) -> NonEmpty a -> NonEmpty a+dropWhile1 p list = case NonEmpty.uncons list of+    (_, Nothing) -> list+    (x, Just xs) -> if p x+        then dropWhile1 p xs+        else list++-- | Calculate layout for multiple horizontal runs on the same line, without+-- any breaking.+layoutRunsH :: [WithSpan Run] -> [WithSpan PF.ProtoFragment]+layoutRunsH runs = map layoutRunH runs++-- | Sum of all advances within the given fragments.+totalAdvances :: [WithSpan PF.ProtoFragment] -> Int32+totalAdvances pfs = sum $ map (\(WithSpan _ pf) -> PF.advance pf) pfs++-- | Calculate layout for the given horizontal run and attach extra information.+layoutRunH :: WithSpan Run -> WithSpan PF.ProtoFragment+layoutRunH (WithSpan rs run) = WithSpan rs pf+    where+        pf = PF.protoFragmentH dir glyphs+        glyphs = shapeRun (WithSpan rs run)+        dir = runDirection run++-- | Calculate layout for the given run independently of its position.+shapeRun :: WithSpan Run -> [(GlyphInfo, GlyphPos)]+shapeRun (WithSpan rs run) = shape font buffer features+    where+        font = RS.spanFont rs+        -- TODO: Set beginsText / endsText.+        buffer = defaultBuffer+            { text = Lazy.fromStrict $ runText run+            , contentType = Just ContentTypeUnicode+            , direction = runDirection run+            , script = runScript run+            , language = Just $ RS.spanLanguage rs+            }+        features = []++resolveSpans :: Paragraph -> [RS.ResolvedSpan]+resolveSpans p@(Paragraph arr pStart spans pOpts) = do+    let sBounds = paragraphSpanBounds p+    let pEnd = NonEmpty.last sBounds+    let sStarts = NonEmpty.init sBounds+    let sLengths = map spanLength spans++    (i, s, sStart, sLen) <- getZipList $ (,,,)+        <$> ZipList [0..]+        <*> ZipList spans+        <*> ZipList sStarts+        <*> ZipList sLengths+    let lang = spanLanguage $ spanOptions s+    let lBreaks = paragraphBreaks breakLine p pEnd lang+    let cBreaks = paragraphBreaks breakCharacter p pEnd lang+    return RS.ResolvedSpan+        { RS.spanIndex = i+        , RS.spanOffsetInParagraph = sStart - pStart+        -- TODO: Consider adding checks for array bounds.+        , RS.spanText = Text arr sStart sLen+        , RS.spanFont = paragraphFont pOpts+        , RS.spanLineHeight = paragraphLineHeight pOpts+        , RS.spanLanguage = lang+        , RS.spanLineBreaks = subOffsetsDesc (sStart - pStart) lBreaks+        , RS.spanCharacterBreaks = subOffsetsDesc (sStart - pStart) cBreaks+        }++paragraphBreaks :: (LocaleName -> Breaker a) -> Paragraph -> Int -> String ->+    [(Int, a)]+paragraphBreaks breakFunc (Paragraph arr off _ _) end lang =+    breaksDesc (breakFunc (localeFromLanguage lang)) paragraphText+    where+        paragraphText = Text arr off (end - off)++runLineBreaks :: WithSpan Run -> [(Int, BreakStatus.Line)]+runLineBreaks (WithSpan rs run) =+    runBreaksFromSpan run $ RS.spanLineBreaks rs++runCharacterBreaks :: WithSpan Run -> [(Int, ())]+runCharacterBreaks (WithSpan rs run) =+    runBreaksFromSpan run $ RS.spanCharacterBreaks rs++-- | Constrain span breaks to a selected run and adjust offsets.+runBreaksFromSpan :: Run -> [(Int, a)] -> [(Int, a)]+runBreaksFromSpan run spanBreaks =+    dropWhile (not . valid) $ subOffsetsDesc (runOffsetInSpan run) spanBreaks+    where+        valid (off, _) = off < runLength+        runLength = lengthWord8 $ getText run++-- | Predicate for characters that can be potentially removed from the end of+-- a line according to the CSS Text Module.+isEndSpace :: Char -> Bool+isEndSpace c = c `elem` [' ', '\t', '\x1680']++-- TODO: Convert from IETF BCP 47 language tag to ICU locale identifier,+--       possibly with an algorithm to find the best matching available locale.+localeFromLanguage :: String -> LocaleName+localeFromLanguage x = Locale $ map (\c -> if c == '-' then '_' else c) x
+ src/Data/Text/ParagraphLayout/Internal/ProtoFragment.hs view
@@ -0,0 +1,25 @@+module Data.Text.ParagraphLayout.Internal.ProtoFragment+    (ProtoFragment(direction, advance, glyphs)+    ,protoFragmentH+    )+where++import Data.Int (Int32)+import Data.Text.Glyphize (Direction, GlyphInfo, GlyphPos(x_advance))++-- | A box fragment which has not been positioned yet.+data ProtoFragment = ProtoFragment+    { direction :: Maybe Direction+    -- ^ Text direction, which is constant within a fragment.+    , advance :: Int32+    -- ^ Total advance of glyphs in this fragment,+    -- depending on the text direction.+    , glyphs :: [(GlyphInfo, GlyphPos)]+    }++-- | Construct a `ProtoFragment`, automatically calculating the total advance+-- for a horizontal text direction.+protoFragmentH :: Maybe Direction -> [(GlyphInfo, GlyphPos)] -> ProtoFragment+protoFragmentH dir gs = ProtoFragment dir adv gs+    where+        adv = sum $ map (x_advance . snd) gs
+ src/Data/Text/ParagraphLayout/Internal/Rect.hs view
@@ -0,0 +1,65 @@+-- | Representation of an axis-aligned rectangle on a 2D plane, with one of its+-- corners being a designated origin point.+module Data.Text.ParagraphLayout.Internal.Rect+    (Rect(Rect, x_origin, y_origin, x_size, y_size)+    ,height+    ,union+    ,width+    ,x_max+    ,x_min+    ,x_terminus+    ,y_max+    ,y_min+    ,y_terminus+    )+where++data Rect a = Rect { x_origin :: a, y_origin :: a, x_size :: a, y_size :: a }+    deriving (Eq, Read, Show)++-- | Absolute difference between the X coordinates of the rectangle's sides.+width :: Num a => Rect a -> a+width r = abs $ x_size r++-- | Absolute difference between the Y coordinates of the rectangle's sides.+height :: Num a => Rect a -> a+height r = abs $ y_size r++-- | X coordinate of the corner opposite of the origin.+x_terminus :: Num a => Rect a -> a+x_terminus r = x_origin r + x_size r++-- | Y coordinate of the corner opposite of the origin.+y_terminus :: Num a => Rect a -> a+y_terminus r = y_origin r + y_size r++-- | The smaller of the two X coordinates of the rectangle's edges.+x_min :: (Num a, Ord a) => Rect a -> a+x_min r = x_origin r `min` x_terminus r++-- | The smaller of the two Y coordinates of the rectangle's edges.+y_min :: (Num a, Ord a) => Rect a -> a+y_min r = y_origin r `min` y_terminus r++-- | The larger of the two X coordinates of the rectangle's edges.+x_max :: (Num a, Ord a) => Rect a -> a+x_max r = x_origin r `max` x_terminus r++-- | The larger of the two Y coordinates of the rectangle's edges.+y_max :: (Num a, Ord a) => Rect a -> a+y_max r = y_origin r `max` y_terminus r++-- | Calculate the smallest rectangle that completely contains the given two+-- rectangles.+--+-- The origin of the resulting rectangle will be the corner with the lowest+-- X coordinate and the highest Y coordinate, regardless of the origin of the+-- input rectangles.+union :: (Num a, Ord a) => Rect a -> Rect a -> Rect a+union a b = Rect x_low y_high dx (-dy) where+    x_low = x_min a `min` x_min b+    y_low = y_min a `min` y_min b+    x_high = x_max a `max` x_max b+    y_high = y_max a `max` y_max b+    dx = x_high - x_low+    dy = y_high - y_low
+ src/Data/Text/ParagraphLayout/Internal/ResolvedSpan.hs view
@@ -0,0 +1,57 @@+module Data.Text.ParagraphLayout.Internal.ResolvedSpan+    (ResolvedSpan(..)+    ,WithSpan(WithSpan)+    ,splitBySpanIndex+    )+where++import Data.Text (Text)+import Data.Text.Glyphize (Font)+import qualified Data.Text.ICU as BreakStatus (Line)++import Data.Text.ParagraphLayout.Internal.LineHeight+import Data.Text.ParagraphLayout.Internal.TextContainer++-- | Internal structure containing resolved values that may be shared with+-- other spans across the paragraph.+data ResolvedSpan = ResolvedSpan+    { spanIndex :: Int+    , spanOffsetInParagraph :: Int+    , spanText :: Text+    , spanFont :: Font+    , spanLineHeight :: LineHeight+    , spanLanguage :: String+    , spanLineBreaks :: [(Int, BreakStatus.Line)]+    -- TODO: Can be optimised by starting with the shortest line break.+    , spanCharacterBreaks :: [(Int, ())]+    }+    deriving (Show)++instance Eq ResolvedSpan where+    a == b = spanIndex a == spanIndex b++instance TextContainer ResolvedSpan where+    getText = spanText++-- | Wrapper for temporarily mapping the relationship to a `Span`.+data WithSpan a = WithSpan ResolvedSpan a++instance Functor WithSpan where+    fmap f (WithSpan s a) = WithSpan s (f a)++instance TextContainer a => TextContainer (WithSpan a) where+    getText (WithSpan _ c) = getText c++instance SeparableTextContainer a => SeparableTextContainer (WithSpan a) where+    splitTextAt8 n (WithSpan rs c) = (WithSpan rs c1, WithSpan rs c2)+        where (c1, c2) = splitTextAt8 n c+    dropWhileEnd p (WithSpan rs c) = WithSpan rs (dropWhileEnd p c)++splitBySpanIndex :: [WithSpan a] -> [[a]]+splitBySpanIndex xs = [getBySpanIndex i xs | i <- [0..]]++getBySpanIndex :: Int -> [WithSpan a] -> [a]+getBySpanIndex idx xs = map contents $ filter matchingIndex $ xs+    where+        matchingIndex (WithSpan rs _) = (spanIndex rs) == idx+        contents (WithSpan _ x) = x
+ src/Data/Text/ParagraphLayout/Internal/Run.hs view
@@ -0,0 +1,133 @@+module Data.Text.ParagraphLayout.Internal.Run (Run(..), spanToRuns)+where++import Data.List (mapAccumL)+import Data.List.NonEmpty (NonEmpty((:|)))+import Data.Text (Text)+import qualified Data.Text as Text+import Data.Text.Foreign (dropWord8, lengthWord8, takeWord8)+import Data.Text.Glyphize (Direction(..))+import qualified Data.Text.ICU.Char as ICUChar++import Data.Text.ParagraphLayout.Internal.ResolvedSpan+import Data.Text.ParagraphLayout.Internal.Script (charScript)+import Data.Text.ParagraphLayout.Internal.TextContainer+import Data.Text.ParagraphLayout.Internal.Zipper++type ScriptCode = String++-- | Each span can be broken into one or more runs by Balkón.+--+-- Each run could have a different script, language, or direction.+data Run = Run+    { runOffsetInSpan :: Int+    , runText :: Text+    , runDirection :: Maybe Direction+    , runScript :: Maybe ScriptCode+    }+    deriving (Eq, Show)++instance TextContainer Run where+    getText = runText++instance SeparableTextContainer Run where+    splitTextAt8 n r =+        ( r { runText = t1 }+        , r { runText = t2, runOffsetInSpan = runOffsetInSpan r + l1 }+        )+        where+            l1 = lengthWord8 t1+            t1 = takeWord8 (fromIntegral n) t+            t2 = dropWord8 (fromIntegral n) t+            t = getText r+    dropWhileEnd p r = r { runText = Text.dropWhileEnd p (runText r) }++type ProtoRun = (Zipper, Maybe Direction, ScriptCode)++-- | Represents a zipper that can advance by at least one character.+data ZipperChoice = ZipperChoice+    { nextChar :: Char+    , continuingRun :: Zipper+    -- ^ The zipper will advance over the next character,+    -- merging it with all preceding characters.+    , startingNewRun :: Zipper+    -- ^ The zipper will forget all preceding characters and then advance over+    -- the next character, making it the first character in a new run of text.+    }++considerNext :: Zipper -> Maybe ZipperChoice+considerNext z = case next z of+    Nothing -> Nothing+    Just c -> Just ZipperChoice+        { nextChar = c+        , continuingRun = step z+        , startingNewRun = step $ start $ following z+        }++data Merged a = Incompatible | Merged a++spanToRuns :: ResolvedSpan -> [Run]+spanToRuns s = snd $ mapAccumL run 0 $ protoRuns zipper+    where+        zipper = start $ spanText s+        run acc (z, d, sc) = let t = preceding z in+            ( acc + lengthWord8 t+            , Run+                { runOffsetInSpan = acc+                , runText = t+                , runDirection = d+                , runScript = Just sc+                }+            )++protoRuns :: Zipper -> [ProtoRun]+protoRuns z = reverse $ protoRuns' z []++protoRuns' :: Zipper -> [ProtoRun] -> [ProtoRun]+protoRuns' curZipper curRuns = case considerNext curZipper of+    Nothing -> curRuns+    Just choice ->+        let headRun@(nextZipper, _, _) :| tailRuns = foldRun choice curRuns+        in protoRuns' nextZipper (headRun:tailRuns)++foldRun :: ZipperChoice -> [ProtoRun] -> NonEmpty ProtoRun++-- If there are no runs, create a new run with a single character.+foldRun x [] = (continuingRun x, d, s) :| []+    where+        d = charDirection (nextChar x)+        s = charScript (nextChar x)++foldRun x (previousRun@(_, d1, s1) : tailRuns) =+    case (mergeDirections d1 d2, mergeScripts s1 s2) of+        (Merged d, Merged s) -> (continuingRun x, d, s) :| tailRuns+        _ -> (startingNewRun x, d2, s2) :| previousRun : tailRuns+    where+        d2 = charDirection (nextChar x)+        s2 = charScript (nextChar x)++-- | Simplified detection of text direction for unidirectional text.+mergeDirections :: Maybe Direction -> Maybe Direction -> Merged (Maybe Direction)+mergeDirections Nothing Nothing = Merged Nothing+mergeDirections (Just d1) Nothing = Merged (Just d1)+mergeDirections Nothing (Just d2) = Merged (Just d2)+mergeDirections (Just d1) (Just d2)+    | d1 == d2 = Merged (Just d1)+    | otherwise = Incompatible++-- TODO: Implement proper inheritance rules.+mergeScripts :: ScriptCode -> ScriptCode -> Merged ScriptCode+mergeScripts "Zyyy" s2 = Merged s2+mergeScripts s1 "Zyyy" = Merged s1+mergeScripts s1 "Zinh" = Merged s1+mergeScripts s1 s2+    | s1 == s2 = Merged s1+    | otherwise = Incompatible++-- TODO: Use the BiDi algorithm to support bidirectional text.+charDirection :: Char -> Maybe Direction+charDirection c = case ICUChar.direction c of+    ICUChar.LeftToRight -> Just DirLTR+    ICUChar.RightToLeft -> Just DirRTL+    ICUChar.RightToLeftArabic -> Just DirRTL+    _ -> Nothing
+ src/Data/Text/ParagraphLayout/Internal/Script.hs view
@@ -0,0 +1,178 @@+module Data.Text.ParagraphLayout.Internal.Script (charScript)+where++-- TODO: Use a direct interface to the ICU library, if possible.+-- The unicode-data-scripts package and the shortening code in this file use+-- hardcoded ranges, which may get out of sync with ICU.+import Unicode.Char.General.Scripts++-- | A short script code for the given character, as expected by HarfBuzz.+charScript :: Char -> String+charScript = code . script++-- Hardcoded shortenings of script codes as of Unicode 15.0.0.+code :: Script -> String+code Adlam = "Adlm"+code Ahom = "Ahom"+code AnatolianHieroglyphs = "Hluw"+code Arabic = "Arab"+code Armenian = "Armn"+code Avestan = "Avst"+code Balinese = "Bali"+code Bamum = "Bamu"+code BassaVah = "Bass"+code Batak = "Batk"+code Bengali = "Beng"+code Bhaiksuki = "Bhks"+code Bopomofo = "Bopo"+code Brahmi = "Brah"+code Braille = "Brai"+code Buginese = "Bugi"+code Buhid = "Buhd"+code CanadianAboriginal = "Cans"+code Carian = "Cari"+code CaucasianAlbanian = "Aghb"+code Chakma = "Cakm"+code Cham = "Cham"+code Cherokee = "Cher"+code Chorasmian = "Chrs"+code Common = "Zyyy"+code Coptic = "Copt"+code Cuneiform = "Xsux"+code Cypriot = "Cprt"+code CyproMinoan = "Cpmn"+code Cyrillic = "Cyrl"+code Deseret = "Dsrt"+code Devanagari = "Deva"+code DivesAkuru = "Diak"+code Dogra = "Dogr"+code Duployan = "Dupl"+code EgyptianHieroglyphs = "Egyp"+code Elbasan = "Elba"+code Elymaic = "Elym"+code Ethiopic = "Ethi"+code Georgian = "Geor"+code Glagolitic = "Glag"+code Gothic = "Goth"+code Grantha = "Gran"+code Greek = "Grek"+code Gujarati = "Gujr"+code GunjalaGondi = "Gong"+code Gurmukhi = "Guru"+code Han = "Hani"+code Hangul = "Hang"+code HanifiRohingya = "Rohg"+code Hanunoo = "Hano"+code Hatran = "Hatr"+code Hebrew = "Hebr"+code Hiragana = "Hira"+code ImperialAramaic = "Armi"+code Inherited = "Zinh"+code InscriptionalPahlavi = "Phli"+code InscriptionalParthian = "Prti"+code Javanese = "Java"+code Kaithi = "Kthi"+code Kannada = "Knda"+code Katakana = "Kana"+code Kawi = "Kawi"+code KayahLi = "Kali"+code Kharoshthi = "Khar"+code KhitanSmallScript = "Kits"+code Khmer = "Khmr"+code Khojki = "Khoj"+code Khudawadi = "Sind"+code Lao = "Laoo"+code Latin = "Latn"+code Lepcha = "Lepc"+code Limbu = "Limb"+code LinearA = "Lina"+code LinearB = "Linb"+code Lisu = "Lisu"+code Lycian = "Lyci"+code Lydian = "Lydi"+code Mahajani = "Mahj"+code Makasar = "Maka"+code Malayalam = "Mlym"+code Mandaic = "Mand"+code Manichaean = "Mani"+code Marchen = "Marc"+code MasaramGondi = "Gonm"+code Medefaidrin = "Medf"+code MeeteiMayek = "Mtei"+code MendeKikakui = "Mend"+code MeroiticCursive = "Merc"+code MeroiticHieroglyphs = "Mero"+code Miao = "Plrd"+code Modi = "Modi"+code Mongolian = "Mong"+code Mro = "Mroo"+code Multani = "Mult"+code Myanmar = "Mymr"+code Nabataean = "Nbat"+code NagMundari = "Nagm"+code Nandinagari = "Nand"+code NewTaiLue = "Talu"+code Newa = "Newa"+code Nko = "Nkoo"+code Nushu = "Nshu"+code NyiakengPuachueHmong = "Hmnp"+code Ogham = "Ogam"+code OlChiki = "Olck"+code OldHungarian = "Hung"+code OldItalic = "Ital"+code OldNorthArabian = "Narb"+code OldPermic = "Perm"+code OldPersian = "Xpeo"+code OldSogdian = "Sogo"+code OldSouthArabian = "Sarb"+code OldTurkic = "Orkh"+code OldUyghur = "Ougr"+code Oriya = "Orya"+code Osage = "Osge"+code Osmanya = "Osma"+code PahawhHmong = "Hmng"+code Palmyrene = "Palm"+code PauCinHau = "Pauc"+code PhagsPa = "Phag"+code Phoenician = "Phnx"+code PsalterPahlavi = "Phlp"+code Rejang = "Rjng"+code Runic = "Runr"+code Samaritan = "Samr"+code Saurashtra = "Saur"+code Sharada = "Shrd"+code Shavian = "Shaw"+code Siddham = "Sidd"+code SignWriting = "Sgnw"+code Sinhala = "Sinh"+code Sogdian = "Sogd"+code SoraSompeng = "Sora"+code Soyombo = "Soyo"+code Sundanese = "Sund"+code SylotiNagri = "Sylo"+code Syriac = "Syrc"+code Tagalog = "Tglg"+code Tagbanwa = "Tagb"+code TaiLe = "Tale"+code TaiTham = "Lana"+code TaiViet = "Tavt"+code Takri = "Takr"+code Tamil = "Taml"+code Tangsa = "Tnsa"+code Tangut = "Tang"+code Telugu = "Telu"+code Thaana = "Thaa"+code Thai = "Thai"+code Tibetan = "Tibt"+code Tifinagh = "Tfng"+code Tirhuta = "Tirh"+code Toto = "Toto"+code Ugaritic = "Ugar"+code Unknown = "Zzzz"+code Vai = "Vaii"+code Vithkuqi = "Vith"+code Wancho = "Wcho"+code WarangCiti = "Wara"+code Yezidi = "Yezi"+code Yi = "Yiii"+code ZanabazarSquare = "Zanb"
+ src/Data/Text/ParagraphLayout/Internal/Span.hs view
@@ -0,0 +1,47 @@+module Data.Text.ParagraphLayout.Internal.Span+    (Span(..)+    ,SpanLayout(..)+    ,SpanOptions(..)+    ,spanRects+    )+where++import Data.Int (Int32)++import Data.Text.ParagraphLayout.Internal.Fragment+import Data.Text.ParagraphLayout.Internal.Rect++-- | A paragraph is broken into spans by the caller.+--+-- Each span could have a different font family, size, style, text decoration,+-- colour, language, etc.+data Span = Span++    { spanLength :: Int+    -- ^ Byte offset to the next span or the end of the paragraph text.++    , spanOptions :: SpanOptions+    -- ^ Options applying to this specific span.++    }+    deriving (Eq, Read, Show)++-- TODO: Add all relevant attributes.+data SpanOptions = SpanOptions++    { spanLanguage :: String+    -- ^ IETF BCP 47 language tag, such as the value expected to be found in+    -- the HTML @lang@ attribute.+    -- Used for selecting the appropriate glyphs and line breaking rules.++    }+    deriving (Eq, Read, Show)++-- | The resulting layout of each span, which may include multiple fragments if+-- broken over multiple lines.+data SpanLayout = SpanLayout [Fragment]+    -- TODO: Consider merging. fragments created by script changes.+    deriving (Eq, Read, Show)++spanRects :: SpanLayout -> [Rect Int32]+spanRects (SpanLayout frags) = map fragmentRect frags
+ src/Data/Text/ParagraphLayout/Internal/TextContainer.hs view
@@ -0,0 +1,89 @@+module Data.Text.ParagraphLayout.Internal.TextContainer+    (SeparableTextContainer+    ,TextContainer+    ,dropWhileEnd+    ,getText+    ,splitTextAt8+    ,splitTextsBy+    ,trimTextsEnd+    )+where++import Data.List.NonEmpty (NonEmpty((:|)))+import Data.Text (Text)+import qualified Data.Text as Text+import Data.Text.Foreign (dropWord8, takeWord8)++-- | Class of data types containing `Text` that can be accessed.+class TextContainer a where+    -- | Extract a `Text` from its container.+    getText :: a -> Text++-- | As a trivial instance, each `Text` contains itself.+instance TextContainer Text where+    getText = id++-- | Class of data types containing `Text` that can be split at a given number+-- of `Data.Word.Word8` units from the start of the text.+class TextContainer a => SeparableTextContainer a where++    -- | Split the given `SeparableTextContainer` at the given number of+    -- `Data.Word.Word8` units from the start of the text, preserving whatever+    -- constraints the instance requires.+    splitTextAt8 :: Int -> a -> (a, a)++    -- | Return the prefix remaining after dropping characters that satisfy+    -- the given predicate from the end of the given `SeparableTextContainer`.+    dropWhileEnd :: (Char -> Bool) -> a -> a++-- | As a trivial instance, each `Text` can be split directly.+instance SeparableTextContainer Text where+    splitTextAt8 n t = (t1, t2)+        where+            t1 = takeWord8 (fromIntegral n) t+            t2 = dropWord8 (fromIntegral n) t+    dropWhileEnd = Text.dropWhileEnd++-- | Treat a list of text containers as a contiguous sequence,+-- and find all possible ways to split them into two non-empty lists,+-- using the given function to find valit split offsets in `Data.Word.Word8`+-- units from the beginning of each container.+--+-- The results in the form (prefix, suffix) will be ordered from the longest+-- prefix to shortest.+splitTextsBy :: SeparableTextContainer a => (a -> [Int]) -> [a] -> [([a], [a])]+splitTextsBy breakFunc tcs =+    filter notEmpty $ splitTextsBy' breakFunc [] (reverse tcs)+    where+        notEmpty (prefix, suffix) = not (null prefix || null suffix)++splitTextsBy' :: SeparableTextContainer a => (a -> [Int]) -> [a] -> [a] ->+    [([a], [a])]+splitTextsBy' _ _ [] = []+splitTextsBy' breakFunc closed (tc:tcs) =+    fullSplits ++ splitTextsBy' breakFunc (tc:closed) tcs+    where+        fullSplits = map mergeWithRest tcSplits+        mergeWithRest (x1, x2) =+            (reverse $ collapse $ x1 :| tcs, collapse $ x2 :| closed)+        tcSplits = map (\i -> splitTextAt8 i tc) tcBreakOffsets+        tcBreakOffsets = breakFunc tc++-- | If the first container in the list is empty, remove it.+collapse :: SeparableTextContainer a => NonEmpty a -> [a]+collapse (tc :| tcs)+    | Text.null (getText tc) = tcs+    | otherwise = tc:tcs++-- | Treat a list of text containers as a contiguous sequence,+-- and remove a suffix of characters that match the given predicate.+trimTextsEnd :: SeparableTextContainer a => (Char -> Bool) -> [a] -> [a]+trimTextsEnd p tcs = trimTextsEnd' p (reverse tcs)++trimTextsEnd' :: SeparableTextContainer a => (Char -> Bool) -> [a] -> [a]+trimTextsEnd' _ [] = []+trimTextsEnd' p (tc:tcs)+    | Text.null (getText trimmed) = trimTextsEnd' p tcs+    | otherwise = reverse $ trimmed:tcs+    where+        trimmed = dropWhileEnd p tc
+ src/Data/Text/ParagraphLayout/Internal/Zipper.hs view
@@ -0,0 +1,136 @@+-- | Zipper API for reading text from start to end.+--+-- All measurements are in UTF-8 code points, each of which can be between+-- 1 and 4 bytes long (inclusive).+module Data.Text.ParagraphLayout.Internal.Zipper+    (Zipper(preceding, following)+    ,advanceBy+    ,atEnd+    ,atStart+    ,next+    ,recombine+    ,splitAt+    ,start+    ,step+    )+where++import Data.Text (measureOff, null, uncons)+import Data.Text.Internal (Text(Text), empty)+import Prelude+    (Bool+    ,Char+    ,Eq+    ,Int+    ,Maybe(Just, Nothing)+    ,Show+    ,fmap+    ,fst+    ,otherwise+    ,(+)+    ,(-)+    ,(.)+    ,(<=)+    ,(>=)+    )++-- | Represents a body of text with a read cursor which can be moved forward.+data Zipper = Zipper { preceding :: Text, following :: Text }+    deriving+        ( Show+        , Eq+        -- ^ /O(n)/ Compare zippers by their contents. Mostly for tests.+        )++-- | /O(1)/ Create a zipper located at the beginning of the given `Text`.+start :: Text -> Zipper+start = splitAt 0++-- | /O(n)/ Create a zipper located @n@ code points into the `Text`,+-- if possible, or located at the beginning or end of the `Text` otherwise.+--+-- Similar to `Data.Text.splitAt`, except the resulting structure holds both+-- halves of the original `Text` and can be moved forward.+splitAt :: Int -> Text -> Zipper+splitAt n t+    | n <= 0 =+        Zipper { preceding = empty, following = t }+    | otherwise = case measureI8 n t of+        Just m ->+            Zipper { preceding = takeWord8 m t, following = dropWord8 m t }+        Nothing ->+            Zipper { preceding = t, following = empty }++-- | /O(1)/ Move the zipper forward one code point, if possible.+step :: Zipper -> Zipper+step = advanceBy 1++-- | /O(n)/ Move the zipper forward at most @n@ code points.+advanceBy :: Int -> Zipper -> Zipper+advanceBy n z+    | n <= 0 = z+    | atEnd z = z+    | otherwise = case measureI8 n (following z) of+        Just m -> advanceByWord8 m z+        Nothing -> Zipper (recombine z) empty++-- | /O(1)/ Produce the original `Text`.+recombine :: Zipper -> Text+recombine (Zipper t1 t2) = recombine' t1 t2++-- | /O(1)/ Test whether the zipper is at the start of a `Text`.+atStart :: Zipper -> Bool+atStart = null . preceding++-- | /O(1)/ Test whether the zipper is at the end of a `Text`.+atEnd :: Zipper -> Bool+atEnd = null . following++-- | /O(1)/ Read the next code point.+next :: Zipper -> Maybe Char+next = fmap fst . uncons . following++-- | /O(n)/ If @t@ is long enough to contain @n@ characters, return their size+-- in `Data.Word.Word8`.+measureI8 :: Int -> Text -> Maybe Int+measureI8 n t =+    let m = measureOff n t in+    if m >= 0+        then Just m+        else Nothing++-- | /O(1)/ Unsafe recombination of two `Text`s.+--+-- Requires that both `Text`s are based on the same `Array` and adjacent to+-- each other.+recombine' :: Text -> Text -> Text+recombine' (Text _ _ 0) t = t+recombine' t (Text _ _ 0) = t+recombine' (Text arr off len1) (Text _ _ len2) = Text arr off (len1 + len2)++-- | /O(1)/ Unsafely move the zipper forward @m@ `Data.Word.Word8` units.+advanceByWord8 :: Int -> Zipper -> Zipper+advanceByWord8 m z = Zipper (recombine' a b) c+    where+        a = preceding z+        b = takeWord8 m (following z)+        c = dropWord8 m (following z)++-- | /O(1)/ Unsafe version of `Data.Text.Foreign.dropWord8`.+--+-- Return the prefix of the `Text` of @m@ `Data.Word.Word8` units in length.+--+-- Requires that @m@ be within the bounds of the `Text`, not at the beginning+-- or at the end, and not inside a code point.+takeWord8 :: Int -> Text -> Text+takeWord8 m (Text arr off _) = Text arr off m++-- | /O(1)/ Unsafe version of `Data.Text.Foreign.dropWord8`.+--+-- Return the suffix of the `Text`, with @m@ `Data.Word.Word8` units dropped+-- from its beginning.+--+-- Requires that @m@ be within the bounds of the `Text`, not at the beginning+-- or at the end, and not inside a code point.+dropWord8 :: Int -> Text -> Text+dropWord8 m (Text arr off len) = Text arr (off+m) (len-m)
+ test/Data/Text/ParagraphLayout/FontLoader.hs view
@@ -0,0 +1,43 @@+module Data.Text.ParagraphLayout.FontLoader+    (loadPlexSansArabicRegular+    ,loadUbuntuRegular+    )+where++import Data.ByteString (readFile)+import Data.Text.Glyphize+    (Font+    ,FontOptions(optionPPEm, optionScale)+    ,createFace+    ,createFontWithOptions+    ,defaultFontOptions+    )+import Prelude (IO, Int, Maybe(Just), String, Word, return, ($))+import System.FilePath ((</>))++-- TODO: Figure out if this affects hinting!+testingPixelSize :: (Word, Word)+testingPixelSize = (24, 24)++-- This controls the output units.+-- The default is "unscaled", which uses the value of `faceUpem` in both axes.+testingScale :: (Int, Int)+testingScale = (1000, 1000)++loadPlexSansArabicRegular :: IO Font+loadPlexSansArabicRegular = loadFontFromFile $+    "assets" </> "fonts" </> "plex" </> "IBMPlexSansArabic-Regular.ttf"++loadUbuntuRegular :: IO Font+loadUbuntuRegular = loadFontFromFile $+    "assets" </> "fonts" </> "ubuntu" </> "Ubuntu-R.ttf"++loadFontFromFile :: String -> IO Font+loadFontFromFile path = do+    ttf <- readFile path+    let face = createFace ttf 0+    let font = createFontWithOptions (defaultFontOptions {+        optionPPEm = Just testingPixelSize,+        optionScale = Just testingScale+    }) face+    return font
+ test/Data/Text/ParagraphLayout/Internal/BreakSpec.hs view
@@ -0,0 +1,122 @@+module Data.Text.ParagraphLayout.Internal.BreakSpec (spec) where++import Data.Text (empty, pack, singleton)+import Data.Text.ICU+    (LocaleName(Locale)+    ,breakCharacter+    ,breakLine+    ,breakSentence+    ,breakWord+    )+import qualified Data.Text.ICU as BreakStatus (Line(..), Word(..))++import Test.Hspec+import Data.Text.ParagraphLayout.Internal.Break++spec :: Spec+spec = do++    describe "breaksDesc" $ do++        -- One of the crucial building blocks of a text layout engine.+        describe "breakLine" $ do+            let b lang = breaksDesc $ breakLine (Locale lang)++            it "finds no breaks in empty input" $+                b "en" empty `shouldBe`+                    []++            it "finds break at offset 0 in non-empty input" $+                b "en" (singleton 'a') `shouldBe`+                    [(0, BreakStatus.Soft)]++            it "finds hard break after newline" $+                b "en" (pack "hello\nworld") `shouldBe`+                    [(6, BreakStatus.Hard)+                    ,(0, BreakStatus.Soft)+                    ]++            it "finds soft breaks after spaces and tabs" $+                b "en" (pack "a few\twords") `shouldBe`+                    [(6, BreakStatus.Soft)+                    ,(2, BreakStatus.Soft)+                    ,(0, BreakStatus.Soft)+                    ]++            it "finds soft breaks after spaces and hyphens" $+                b "cs" (pack "následuje stanice Frýdek-Místek") `shouldBe`+                    [(27, BreakStatus.Soft)+                    ,(19, BreakStatus.Soft)+                    ,(11, BreakStatus.Soft)+                    ,(0, BreakStatus.Soft)+                    ]++            it "finds soft breaks in Japanese kana" $+                b "ja" (pack "トイレはどこですか？") `shouldBe`+                    [(24, BreakStatus.Soft)+                    ,(21, BreakStatus.Soft)+                    ,(18, BreakStatus.Soft)+                    ,(15, BreakStatus.Soft)+                    ,(12, BreakStatus.Soft)+                    ,(9, BreakStatus.Soft)+                    ,(6, BreakStatus.Soft)+                    ,(3, BreakStatus.Soft)+                    ,(0, BreakStatus.Soft)+                    ]++        -- Probably not useful for a web browser rendering engine.+        describe "breakSentence" $ do+            let b lang = breaksDesc $ breakSentence (Locale lang)++            it "finds no breaks in empty input" $+                b "en" empty `shouldBe`+                    []++            it "finds break at offset 0 in non-empty input" $+                b "en" (singleton 'a') `shouldBe`+                    [(0, ())]++        -- Probably not useful for a web browser rendering engine,+        -- but may be used for text search and selection.+        describe "breakWord" $ do+            let b lang = breaksDesc $ breakWord (Locale lang)++            it "finds no breaks in empty input" $+                b "en" empty `shouldBe`+                    []++            it "finds break at offset 0 in non-empty input" $+                b "en" (singleton 'a') `shouldBe`+                    [(0, BreakStatus.Uncategorized)]++            it "finds breaks after runs of letters and spaces" $+                b "en" (pack "a few   words") `shouldBe`+                    [(8, BreakStatus.Uncategorized)+                    ,(5, BreakStatus.Letter)+                    ,(2, BreakStatus.Uncategorized)+                    ,(1, BreakStatus.Letter)+                    ,(0, BreakStatus.Uncategorized)+                    ]++        -- Useful for breaking inside words for narrow output.+        -- This can result in breaking ligatures.+        describe "breakCharacter" $ do+            let b lang = breaksDesc $ breakCharacter (Locale lang)++            it "finds no breaks in empty input" $+                b "en" empty `shouldBe`+                    []++            it "finds break at offset 0 in non-empty input" $+                b "en" (singleton 'a') `shouldBe`+                    [(0, ())]++    describe "subOffsetsDesc" $ do++        let result = subOffsetsDesc 5 [(11, 'a'), (8, 'b'), (5, 'c'), (2, 'd')]++        it "should reduce offsets" $+            map fst result `shouldBe` [6, 3, 0]++        it "should preserve payload" $+            map snd result `shouldBe` ['a', 'b', 'c']
+ test/Data/Text/ParagraphLayout/Internal/RunSpec.hs view
@@ -0,0 +1,45 @@+module Data.Text.ParagraphLayout.Internal.RunSpec (spec) where++import Data.Text (pack)+import Data.Text.Glyphize (Direction(..))++import Test.Hspec+import Data.Text.ParagraphLayout.FontLoader+import Data.Text.ParagraphLayout.Internal.ResolvedSpan+import Data.Text.ParagraphLayout.Internal.Run+import Data.Text.ParagraphLayout.SpanData++spec :: Spec+spec = do+    describe "spanToRuns" $ before loadUbuntuRegular $ do+        it "handles span with no text" $ \font -> do+            spanToRuns (emptySpan font) `shouldBe` []+        it "handles Czech hello" $ \font -> do+            let inputSpan = czechHello font+            let runs = spanToRuns inputSpan+            runs `shouldBe`+                [ Run+                    { runOffsetInSpan = 0+                    , runText = spanText inputSpan+                    , runDirection = Just DirLTR+                    , runScript = Just "Latn"+                    }+                ]+        it "handles Serbian with mixed script" $ \font -> do+            let inputSpan = serbianMixedScript font+            let runs = spanToRuns inputSpan+            runs `shouldBe`+                [ Run+                    -- TODO: We might want both parentheses in the same run.+                    { runOffsetInSpan = 0+                    , runText = pack "Vikipedija ("+                    , runDirection = Just DirLTR+                    , runScript = Just "Latn"+                    }+                , Run+                    { runOffsetInSpan = 12+                    , runText = pack "Википедија)"+                    , runDirection = Just DirLTR+                    , runScript = Just "Cyrl"+                    }+                ]
+ test/Data/Text/ParagraphLayout/Internal/TextContainerSpec.hs view
@@ -0,0 +1,122 @@+module Data.Text.ParagraphLayout.Internal.TextContainerSpec (spec) where++import Data.Text (Text, empty, pack)+import Data.Text.Foreign (lengthWord8)++import Test.Hspec+import Data.Text.ParagraphLayout.Internal.TextContainer++data ExampleContainer = Contain { cText :: Text, cOffset :: Int }+    deriving (Show, Eq)++contain :: String -> Int -> ExampleContainer+contain s o = Contain (pack s) o++instance TextContainer ExampleContainer where+    getText = cText++instance SeparableTextContainer ExampleContainer where+    splitTextAt8 n (Contain t o) = (Contain t1 o1, Contain t2 o2)+        where+            (t1, t2) = splitTextAt8 n t+            o1 = o+            o2 = o + lengthWord8 t1+    dropWhileEnd p (Contain t o) = Contain (dropWhileEnd p t) o++exampleContainers :: [ExampleContainer]+exampleContainers = [c1, c2]+    where+        (c1, c2) = splitTextAt8 11 $ contain "Vikipedija (Википедија)" 10++exampleBreaks :: [Int]+exampleBreaks =+    [+    -- Out of bounds. Should not generate any splits.+    999, 50,+    -- End of last text. Should not generate a split.+    43,+    -- Word and syllable bounds in the second text,+    -- similar to hyphenation rules. Each should generate a corresponding split.+    38, 34, 30, 26,+    -- The exact edge between the two texts.+    -- Should generate a split, but not any empty containers.+    21,+    -- Word and syllable bounds in the first text.+    -- Each should generate a corresponding split.+    18, 16, 14, 12,+    -- Start of first text. Should not generate a split.+    10,+    -- Out of bounds. Should not generate any splits.+    5, 0, -1+    ]++exampleBreakPoints :: ExampleContainer -> [Int]+exampleBreakPoints c =+    dropWhile (>= l) $ takeWhile (>= 0) $ map (subtract d) $ exampleBreaks+    where+        l = lengthWord8 $ cText c+        d = cOffset c++isSpace :: Char -> Bool+isSpace = (==' ')++spec :: Spec+spec = do+    describe "splitTextsBy" $ do+        it "splits example text containers" $ do+            splitTextsBy exampleBreakPoints exampleContainers `shouldBe`+                [ ( [ contain "Vikipedija " 10, contain "(Википеди" 21 ]+                  , [ contain "ја)" 38 ]+                  )+                , ( [ contain "Vikipedija " 10, contain "(Википе" 21 ]+                  , [ contain "дија)" 34 ]+                  )+                , ( [ contain "Vikipedija " 10, contain "(Вики" 21 ]+                  , [ contain "педија)" 30 ]+                  )+                , ( [ contain "Vikipedija " 10, contain "(Ви" 21 ]+                  , [ contain "кипедија)" 26 ]+                  )+                , ( [ contain "Vikipedija " 10 ]+                  , [ contain "(Википедија)" 21 ]+                  )+                , ( [ contain "Vikipedi" 10 ]+                  , [ contain "ja " 18, contain "(Википедија)" 21 ]+                  )+                , ( [ contain "Vikipe" 10 ]+                  , [ contain "dija " 16, contain "(Википедија)" 21 ]+                  )+                , ( [ contain "Viki" 10 ]+                  , [ contain "pedija " 14, contain "(Википедија)" 21 ]+                  )+                , ( [ contain "Vi" 10 ]+                  , [ contain "kipedija " 12, contain "(Википедија)" 21 ]+                  )+                ]+    describe "trimTextsEnd" $ do+        describe "isSpace" $ do+            it "does nothing on an empty list" $ do+                let inputTexts = [] :: [Text]+                trimTextsEnd isSpace inputTexts `shouldBe` inputTexts+            it "does nothing when last run does not end with space" $ do+                let inputTexts = [pack "some ", pack "text"]+                trimTextsEnd isSpace inputTexts `shouldBe` inputTexts+            it "trims empty texts down to an empty list" $ do+                let inputTexts = [empty, empty, empty]+                trimTextsEnd isSpace inputTexts `shouldBe` []+            it "trims empty texts from a list" $ do+                let inputTexts = [pack "some ", pack "text", empty, empty]+                trimTextsEnd isSpace inputTexts `shouldBe`+                    [pack "some ", pack "text"]+            it "trims spaces from last text" $ do+                let inputTexts = [pack "some ", pack "text      "]+                trimTextsEnd isSpace inputTexts `shouldBe`+                    [pack "some ", pack "text"]+            it "trims texts containing only spaces" $ do+                let inputTexts = [pack "some ", pack "text", pack "    "]+                trimTextsEnd isSpace inputTexts `shouldBe`+                    [pack "some ", pack "text"]+            it "trims last text that contains non-spaces" $ do+                let inputTexts = [pack "some ", pack "text  ", pack "    "]+                trimTextsEnd isSpace inputTexts `shouldBe`+                    [pack "some ", pack "text"]
+ test/Data/Text/ParagraphLayout/Internal/ZipperSpec.hs view
@@ -0,0 +1,166 @@+module Data.Text.ParagraphLayout.Internal.ZipperSpec (spec) where++import Control.Monad (forM_)+import Data.Text (Text, empty, pack)+import qualified Data.Text as Text++import Test.Hspec+import qualified Data.Text.ParagraphLayout.Internal.Zipper as Zipper++sampleText :: Text+sampleText =+    Text.dropEnd 6 $+    Text.drop 4 $+    pack "xxx Příliš žluťoučký kůň úpěl ďábelské ódy. yyyyy"++sampleLength :: Int+sampleLength = 39++midPositions :: [Int]+midPositions = [1, 2, 5, 8, 38]++preMidPositions :: [Int]+preMidPositions = map pred midPositions++spec :: Spec+spec = do++    describe "start on empty text" $ do+        let z = Zipper.start empty+        it "is at start" $ do+            Zipper.atStart z `shouldBe` True+        it "is at end" $ do+            Zipper.atEnd z `shouldBe` True+        it "has nothing preceding it" $ do+            Zipper.preceding z `shouldBe` empty+        it "has nothing following it" $ do+            Zipper.following z `shouldBe` empty+        it "has no next character" $ do+            Zipper.next z `shouldBe` Nothing+        it "recombines into empty text" $ do+            Zipper.recombine z `shouldBe` empty+        it "unchanged by step" $ do+            Zipper.step z `shouldBe` z+        it "unchanged by advance" $ do+            Zipper.advanceBy 999 z `shouldBe` z++    describe "start" $ do+        let z = Zipper.start sampleText+        it "is at start" $ do+            Zipper.atStart z `shouldBe` True+        it "is not at end" $ do+            Zipper.atEnd z `shouldBe` False+        it "has nothing preceding it" $ do+            Zipper.preceding z `shouldBe` empty+        it "has everything following it" $ do+            Zipper.following z `shouldBe` sampleText+        it "has next character 'P'" $ do+            Zipper.next z `shouldBe` Just 'P'+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText++    describe "split at zero" $ do+        let z = Zipper.splitAt 0 sampleText+        it "is at start" $ do+            Zipper.atStart z `shouldBe` True+        it "is not at end" $ do+            Zipper.atEnd z `shouldBe` False+        it "has nothing preceding it" $ do+            Zipper.preceding z `shouldBe` empty+        it "has everything following it" $ do+            Zipper.following z `shouldBe` sampleText+        it "has next character 'P'" $ do+            Zipper.next z `shouldBe` Just 'P'+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText++    describe "split at negative value" $ do+        let z = Zipper.splitAt (-3) sampleText+        it "is at start" $ do+            Zipper.atStart z `shouldBe` True+        it "is not at end" $ do+            Zipper.atEnd z `shouldBe` False+        it "has nothing preceding it" $ do+            Zipper.preceding z `shouldBe` empty+        it "has everything following it" $ do+            Zipper.following z `shouldBe` sampleText+        it "has next character 'P'" $ do+            Zipper.next z `shouldBe` Just 'P'+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText++    midPositions `forM_` \n ->+        describe ("split at " ++ (show n)) $ do+            let z = Zipper.splitAt n sampleText+            it "is not at start" $ do+                Zipper.atStart z `shouldBe` False+            it "is not at end" $ do+                Zipper.atEnd z `shouldBe` False+            it ("preceding text has length " ++ show n) $ do+                Text.length (Zipper.preceding z) `shouldBe` n+            it ("following text has length " ++ show (sampleLength-n)) $ do+                Text.length (Zipper.following z) `shouldBe` (sampleLength-n)+            it "recombines into original text" $ do+                Zipper.recombine z `shouldBe` sampleText++    preMidPositions `forM_` \n ->+        describe ("split at " ++ (show n) ++ " and step") $ do+            let z = Zipper.step $ Zipper.splitAt n sampleText+            it "is not at start" $ do+                Zipper.atStart z `shouldBe` False+            it "is not at end" $ do+                Zipper.atEnd z `shouldBe` False+            it ("preceding text has length " ++ show (n+1)) $ do+                Text.length (Zipper.preceding z) `shouldBe` (n+1)+            it ("following text has length " ++ show (sampleLength-n-1)) $ do+                Text.length (Zipper.following z) `shouldBe` (sampleLength-n-1)+            it "recombines into original text" $ do+                Zipper.recombine z `shouldBe` sampleText++    describe "start and advance by 3" $ do+        let z = Zipper.advanceBy 3 $ Zipper.start sampleText+        it "should be the same as splitting at 3" $ do+            z `shouldBe` Zipper.splitAt 3 sampleText+        it "has next character 'l'" $ do+            Zipper.next z `shouldBe` Just 'l'+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText++    describe "split at 4 and advance by 3" $ do+        let z = Zipper.advanceBy 3 $ Zipper.splitAt 4 sampleText+        it "should be the same as splitting at 7" $ do+            z `shouldBe` Zipper.splitAt 7 sampleText+        it "has next character z-caron" $ do+            Zipper.next z `shouldBe` Just 'ž'+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText++    describe "split past text bounds" $ do+        let z = Zipper.splitAt 999 sampleText+        it "is not at start" $ do+            Zipper.atStart z `shouldBe` False+        it "is at end" $ do+            Zipper.atEnd z `shouldBe` True+        it "has everything preceding it" $ do+            Zipper.preceding z `shouldBe` sampleText+        it "has nothing following it" $ do+            Zipper.following z `shouldBe` empty+        it "has no next character" $ do+            Zipper.next z `shouldBe` Nothing+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText++    describe "split at 3 and advance past text bounds" $ do+        let z = Zipper.advanceBy sampleLength $ Zipper.splitAt 3 sampleText+        it "is not at start" $ do+            Zipper.atStart z `shouldBe` False+        it "is at end" $ do+            Zipper.atEnd z `shouldBe` True+        it "has everything preceding it" $ do+            Zipper.preceding z `shouldBe` sampleText+        it "has nothing following it" $ do+            Zipper.following z `shouldBe` empty+        it "has no next character" $ do+            Zipper.next z `shouldBe` Nothing+        it "recombines into original text" $ do+            Zipper.recombine z `shouldBe` sampleText
+ test/Data/Text/ParagraphLayout/ParagraphData.hs view
@@ -0,0 +1,80 @@+module Data.Text.ParagraphLayout.ParagraphData+    (arabicFillerParagraph+    ,czechHelloParagraph+    ,emptyParagraph+    ,emptySpanParagraph+    ,ligatureParagraph+    ,loremIpsumParagraph+    ,mixedLanguageLTRParagraph+    ,mixedScriptSerbianParagraph+    ,mixedScriptWordsParagraph+    ,spannedArabicFillerParagraph+    ,spannedLoremIpsumParagraph+    ,trivialParagraph+    )+where++import Data.Text.ParagraphLayout (Paragraph, ParagraphOptions, SpanOptions(..))+import Data.Text.ParagraphLayout.ParagraphConstruction++-- | Span with text in the Czech language.+cs :: String -> (SpanOptions, String)+cs = (,) SpanOptions { spanLanguage = "cs" }++-- | Span with text in the English language.+en :: String -> (SpanOptions, String)+en = (,) SpanOptions { spanLanguage = "en" }++-- | Span with text in the Japanese language.+ja :: String -> (SpanOptions, String)+ja = (,) SpanOptions { spanLanguage = "ja" }++-- | Span with text in the Serbian language.+sr :: String -> (SpanOptions, String)+sr = (,) SpanOptions { spanLanguage = "sr" }++-- | Span with text in no language.+zxx :: String -> (SpanOptions, String)+zxx = (,) SpanOptions { spanLanguage = "zxx" }++emptyParagraph :: ParagraphOptions -> Paragraph+emptyParagraph = "x" |<>| "zzzzzzz"++emptySpanParagraph :: ParagraphOptions -> Paragraph+emptySpanParagraph = "xx" |< en "" >| "zzzzz"++trivialParagraph :: ParagraphOptions -> Paragraph+trivialParagraph = "xxx" |< en "a" >| "zzz"++ligatureParagraph :: ParagraphOptions -> Paragraph+ligatureParagraph = "" |< en "inefficient" >| ""++-- | Fillter text using the Arabic script.+-- Source: <https://generator.lorem-ipsum.info/_arabic>+arabicFillerParagraph :: ParagraphOptions -> Paragraph+arabicFillerParagraph = "xxxx" |< zxx "إعلان بأيدي وبغطاء هذه من. عرض غينيا يتمكن واعتلاء في. و فرنسا الثانية وفي, أسر إذ السبب ارتكبها مليارات. فكان الشتاء، ما حتى, غير أن وصغار الأخذ. في الصفحة لهيمنة وتتحمّل وتم, أن أما وبداية الغالي." >| "z"++spannedArabicFillerParagraph :: ParagraphOptions -> Paragraph+spannedArabicFillerParagraph = "xxxx" |< zxx "إعلان بأيدي وبغطاء " >|< zxx "هذه من. عرض" >|< zxx " غينيا يتمكن واعتلاء " >|< zxx "في. و فرنسا" >|< zxx " الثانية وفي, أسر " >|< zxx "إذ السبب ارتكبها" >|< zxx " مليارات. فكان الشتاء، " >|< zxx "ما حتى, غير" >|< zxx " أن وصغار الأخذ. " >|< zxx "في الصفحة لهيمنة" >|< zxx " وتتحمّل وتم, أن " >|< zxx "أما وبداية الغالي." >| "z"++-- | Fillter text using the Latin script.+-- Source: <https://www.lipsum.com/>+loremIpsumParagraph :: ParagraphOptions -> Paragraph+loremIpsumParagraph = "xxxx" |< zxx "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum." >| "z"++spannedLoremIpsumParagraph :: ParagraphOptions -> Paragraph+spannedLoremIpsumParagraph = "xxxx" |< zxx "Lorem ipsum dolor " >|< zxx "sit amet, consectetur" >|< zxx " adipiscing elit, sed " >|< zxx "do eiusmod tempor" >|< zxx " incididunt ut labore " >|< zxx "et dolore magna" >|< zxx " aliqua. Ut enim " >|< zxx "ad minim veniam," >|< zxx " quis nostrud exercitation " >|< zxx "ullamco laboris nisi" >|< zxx " ut aliquip ex " >|< zxx "ea commodo consequat." >|< zxx " Duis aute irure " >|< zxx "dolor in reprehenderit" >|< zxx " in voluptate velit " >|< zxx "esse cillum dolore" >|< zxx " eu fugiat nulla " >|< zxx "pariatur. Excepteur" >|< zxx " sint occaecat cupidatat " >|< zxx "non proident, sunt" >|< zxx " in culpa qui " >|< zxx "officia deserunt mollit" >|< zxx " anim id est " >|< zxx "laborum." >| "z"++czechHelloParagraph :: ParagraphOptions -> Paragraph+czechHelloParagraph = "xxxxx" |< cs "Ahoj, světe!" >| "zz"++mixedScriptSerbianParagraph :: ParagraphOptions -> Paragraph+mixedScriptSerbianParagraph = "xxxxxx" |< sr "Vikipedija (Википедија)" >| "zzzz"++-- | For testing line breaking on boundaries that are different from script+-- boundaries.+mixedScriptWordsParagraph :: ParagraphOptions -> Paragraph+mixedScriptWordsParagraph = "xxxxxxx" |< zxx "jjjжжжjjj jjjжжжjjj жжжjjjжжж жжжjjjжжж jжj jжj жjж жjж" >| "zzzzzzzz"++mixedLanguageLTRParagraph :: ParagraphOptions -> Paragraph+mixedLanguageLTRParagraph = "Tak " |< cs "jsem tady, " >|< ja "世界!" >| "zzzzzz"
+ test/Data/Text/ParagraphLayout/RectSpec.hs view
@@ -0,0 +1,29 @@+module Data.Text.ParagraphLayout.RectSpec (spec) where++import Data.Int (Int32)++import Test.Hspec+import Data.Text.ParagraphLayout.Internal.Rect++positiveRect :: Rect Int32+positiveRect = Rect 50 (-70) 10 10++negativeRect :: Rect Int32+negativeRect = Rect 80 (-75) (-15) (-15)++spec :: Spec+spec = do+    describe "union of two rects" $ do+        let r = union positiveRect negativeRect+        it "has origin at 50,-60" $+            (x_origin r, y_origin r) `shouldBe` (50, -60)+        it "has minimum coordinates at at 50,-90" $+            (x_min r, y_min r) `shouldBe` (50, -90)+        it "has terminus at 80,-90" $+            (x_terminus r, y_terminus r) `shouldBe` (80, -90)+        it "has maximum coordinates at 80,-60" $+            (x_max r, y_max r) `shouldBe` (80, -60)+        it "has size 30,-30" $+            (x_size r, y_size r) `shouldBe` (30, -30)+        it "has absolute size 30,30" $+            (width r, height r) `shouldBe` (30, 30)
+ test/Data/Text/ParagraphLayout/SpanData.hs view
@@ -0,0 +1,47 @@+module Data.Text.ParagraphLayout.SpanData+    (emptySpan+    ,czechHello+    ,serbianMixedScript+    )+where++import Data.Text (pack)+import Data.Text.Glyphize (Font)+import Data.Text.ParagraphLayout (LineHeight(Normal))+import Data.Text.ParagraphLayout.Internal.ResolvedSpan (ResolvedSpan(..))++emptySpan :: Font -> ResolvedSpan+emptySpan font = ResolvedSpan+    { spanIndex = 0+    , spanOffsetInParagraph = 0+    , spanText = pack ""+    , spanFont = font+    , spanLineHeight = Normal+    , spanLanguage = "en"+    , spanLineBreaks = []+    , spanCharacterBreaks = []+    }++czechHello :: Font -> ResolvedSpan+czechHello font = ResolvedSpan+    { spanIndex = 0+    , spanOffsetInParagraph = 0+    , spanText = pack "Ahoj, světe!"+    , spanFont = font+    , spanLineHeight = Normal+    , spanLanguage = "cs"+    , spanLineBreaks = []+    , spanCharacterBreaks = []+    }++serbianMixedScript :: Font -> ResolvedSpan+serbianMixedScript font = ResolvedSpan+    { spanIndex = 0+    , spanOffsetInParagraph = 0+    , spanText = pack "Vikipedija (Википедија)"+    , spanFont = font+    , spanLineHeight = Normal+    , spanLanguage = "sr"+    , spanLineBreaks = []+    , spanCharacterBreaks = []+    }
+ test/Data/Text/ParagraphLayoutSpec.hs view
@@ -0,0 +1,194 @@+module Data.Text.ParagraphLayoutSpec (spec) where++import Data.List (intersperse)+import Data.Text.Glyphize (Font)++import Test.Hspec+import Test.Hspec.Golden+import System.FilePath ((</>))+import Data.Text.ParagraphLayout+import Data.Text.ParagraphLayout.FontLoader+import Data.Text.ParagraphLayout.ParagraphData+import Data.Text.ParagraphLayout.Rect+++prettyShow :: ParagraphLayout -> String+prettyShow (ParagraphLayout pr sls) = showParagraphLayout where+    showParagraphLayout = concat+        [ "ParagraphLayout {paragraphRect = "+        , show pr+        , ", spanLayouts = ["+        , newline+        , showSpanLayouts+        , newline+        , "]}"+        , newline+        ]+    showSpanLayouts = concat $ intersperse commaNewline $ map showSpanLayout sls+    showSpanLayout (SpanLayout frags) = concat+        [ indent1+        , "SpanLayout ["+        , concat $ intersperse ", " $ map showFrag frags+        , "]"+        ]+    showFrag (Fragment r pen glyphs) = concat+        [ "Fragment {fragmentRect = "+        , show r+        , ", "+        , "fragmentPen = "+        , show pen+        , ", "+        , "fragmentGlyphs ="+        , newline+        , indent2+        , "["+        , showGlyphs glyphs+        , "]"+        , newline+        , indent1+        , "}"+        ]+    showGlyphs = concat . intersperse (commaNewline ++ indent2) . map show+    indent1 = "    "+    indent2 = indent1 ++ indent1+    newline = "\n"+    commaNewline = "," ++ newline++shouldBeGolden :: ParagraphLayout -> FilePath -> Golden ParagraphLayout+shouldBeGolden output_ name = Golden+    { output = output_+    , encodePretty = show+    , writeToFile = \path -> writeFile path . prettyShow+    , readFromFile = \path -> readFile path >>= return . read+    , goldenFile = ".golden" </> name </> "golden"+    , actualFile = Just (".golden" </> name </> "actual")+    , failFirstTime = False+    }++emptyLayout :: ParagraphLayout+emptyLayout = ParagraphLayout (Rect 0 0 0 0) []++emptySpanLayout :: ParagraphLayout+emptySpanLayout = ParagraphLayout (Rect 0 0 0 0) [SpanLayout []]++opts :: Font -> ParagraphOptions+opts font = ParagraphOptions font Normal 8000++spec :: Spec+spec = do+    -- Note: This font does not contain Japanese glyphs.+    describe "layoutPlain" $ do+        describe "with Arabic font" $ before loadPlexSansArabicRegular $ do+            it "handles input with no spans" $ \font -> do+                let result = layoutPlain $ emptyParagraph $ opts font+                result `shouldBe` emptyLayout+            it "wraps filler text at 20em" $ \font -> do+                let+                    result = layoutPlain $ arabicFillerParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                result `shouldBeGolden` "arabicFiller20em"+            it "wraps filler text with spans at 20em" $ \font -> do+                let+                    result = layoutPlain $ spannedArabicFillerParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                result `shouldBeGolden` "spannedArabicFiller20em"+            it "spans do not reposition filler text at 20em" $ \font -> do+                let+                    withoutSpans = layoutPlain $ arabicFillerParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                    withSpans = layoutPlain $ spannedArabicFillerParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                paragraphRect withoutSpans `shouldBe` paragraphRect withSpans+        describe "with Latin font" $ before loadUbuntuRegular $ do+            it "handles input with no spans" $ \font -> do+                let result = layoutPlain $ emptyParagraph $ opts font+                result `shouldBe` emptyLayout+            it "handles one span with no text" $ \font -> do+                let result = layoutPlain $ emptySpanParagraph $ opts font+                result `shouldBe` emptySpanLayout+            it "handles Czech hello" $ \font -> do+                let result = layoutPlain $ czechHelloParagraph $ opts font+                result `shouldBeGolden` "czechHelloParagraph"+            it "renders an \"ffi\" ligature" $ \ font -> do+                let result = layoutPlain $ ligatureParagraph $ opts font+                result `shouldBeGolden` "ligatureParagraph"+            it "breaks an \"ffi\" ligature into \"ff\" + \"i\"" $ \ font -> do+                let result = layoutPlain $ ligatureParagraph $+                        (opts font)+                        { paragraphMaxWidth = 2418 }+                result `shouldBeGolden` "ligatureParagraphBreak1"+            it "breaks an \"ffi\" ligature into \"f\" + \"fi\"" $ \ font -> do+                let result = layoutPlain $ ligatureParagraph $+                        (opts font)+                        { paragraphMaxWidth = 1800 }+                result `shouldBeGolden` "ligatureParagraphBreak2"+            it "handles mixed languages in LTR layout" $ \font -> do+                let result = layoutPlain $ mixedLanguageLTRParagraph $ opts font+                result `shouldBeGolden` "mixedLanguageLTRParagraph"+            it "handles normal line height" $ \font -> do+                let+                    result = layoutPlain $ trivialParagraph $+                        (opts font)+                        { paragraphLineHeight = Normal }+                result `shouldBeGolden` "lineHeightNormal"+            it "handles larger line height" $ \font -> do+                let+                    result = layoutPlain $ trivialParagraph $+                        (opts font)+                        { paragraphLineHeight = Absolute 1600 }+                result `shouldBeGolden` "lineHeightLarger"+            it "handles smaller line height" $ \font -> do+                let+                    result = layoutPlain $ trivialParagraph $+                        (opts font)+                        { paragraphLineHeight = Absolute 599 }+                result `shouldBeGolden` "lineHeightSmaller"+            it "wraps mid-word when line is narrow" $ \font -> do+                let+                    result = layoutPlain $ czechHelloParagraph $+                        (opts font)+                        { paragraphMaxWidth = 1300 }+                result `shouldBeGolden` "czechHelloParagraphNarrow"+            it "wraps by characters when line is ultra narrow" $ \font -> do+                let+                    result = layoutPlain $ czechHelloParagraph $+                        (opts font)+                        { paragraphMaxWidth = 100 }+                result `shouldBeGolden` "czechHelloParagraphUltraNarrow"+            it "wraps lorem ipsum at 20em" $ \font -> do+                let+                    result = layoutPlain $ loremIpsumParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                result `shouldBeGolden` "loremIpsum20em"+            it "wraps lorem ipsum at 100em" $ \font -> do+                let+                    result = layoutPlain $ loremIpsumParagraph $+                        (opts font)+                        { paragraphMaxWidth = 100000 }+                result `shouldBeGolden` "loremIpsum100em"+            it "wraps lorem ipsum with spans at 20em" $ \font -> do+                let+                    result = layoutPlain $ spannedLoremIpsumParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                result `shouldBeGolden` "spannedLoremIpsum20em"+            it "spans do not reposition lorem ipsum at 20em" $ \font -> do+                let+                    withoutSpans = layoutPlain $ loremIpsumParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                    withSpans = layoutPlain $ spannedLoremIpsumParagraph $+                        (opts font)+                        { paragraphMaxWidth = 20000 }+                paragraphRect withoutSpans `shouldBe` paragraphRect withSpans+            it "wraps mixed-script words correctly" $ \font -> do+                let+                    result = layoutPlain $ mixedScriptWordsParagraph $+                        (opts font)+                        { paragraphMaxWidth = 6000 }+                result `shouldBeGolden` "mixedScriptWordsParagraph"
+ test/Spec.hs view
@@ -0,0 +1,1 @@+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}