diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright (c) 2013, Francesco Ariis + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + + * Neither the name of Francesco Ariis nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/Text/LineBreak.hs b/Text/LineBreak.hs new file mode 100644 --- /dev/null +++ b/Text/LineBreak.hs @@ -0,0 +1,138 @@ +-------------------------------------------------------------------------------- +-- | +-- Module : Text.LineBreak +-- Copyright : (C) 2013 Francesco Ariis +-- License : BSD3 (see LICENSE file) +-- +-- Maintainer : Francesco Ariis +-- Stability : provisional +-- Portability : portable +-- +-- Simple functions to break a String to fit a maximum text width, using +-- Knuth-Lian hyphenation algorithm. +-- +-- Example: +-- +-- > import Text.Hyphenation +-- > import Text.LineBreak +-- > +-- > hyp = Just english_US +-- > bf = BreakFormat 25 '-' hyp +-- > cs = "Using hyphenation with gruesomely non parsimonious wording." +-- > +-- > main = putStr $ breakString bf cs +-- +-- will output: +-- +-- > Using hyphenation with +-- > gruesomely non parsimo- +-- > nious wording. +-- +------------------------------------------------------------------------------- + +module Text.LineBreak ( breakString, breakStringLn, BreakFormat (..) ) where + +import Data.List (intercalate) +import Text.Hyphenation + +-- TODO: what to do in overflow case? + +-- @ +-- let hyp = Just english_US in +-- putStr $ breakString (BreakFormat 55 '-' hyp) str2 +-- @ +-- +-- @ +-- Mathematicians seek out patterns and use them to formu- +-- late new conjectures. Mathematicians resolve the truth +-- or falsity of conjectures by mathematical proof. +-- @ + +-- TYPES -- + +-- | How to break the Strings: maximum width of the lines, symbol to use +-- to hyphenate a word, Hypenator to use (language, exceptions, etc. Refer to +-- "Text.Hyphenation" for more info). To break lines without hyphenating, put +-- @Nothing@ in @bfHyphenator@. +data BreakFormat = BreakFormat { bfMaxCol :: Int, + bfHyphenSymbol :: Char, + bfHyphenator :: Maybe Hyphenator } + + +-- bit: hyphenated part of a word +data WordPart = Init | Mid | End | Single + deriving (Eq, Show) + +isInit Init = True +isInit Single = True +isInit _ = False + +isEnd End = True +isEnd Single = True +isEnd _ = False + + +putBit :: String -> BreakFormat -> WordPart -> String -> String +putBit oldcs (BreakFormat maxcol hypsym _) wp bit = + let + spaceleft = + maxcol - currcol + + (if isInit wp then (-1) else 0) + -- new world + (if not $ isEnd wp then (-1) else 0) -- possible hyp. space + lenbit = length bit + + addbefore + -- begin of word, no space left + | isInit wp && lenbit > spaceleft = "\n" -- put newline + -- begin of word, not @ first column + | isInit wp && currcol /= 0 = " " -- put space + -- not begin of word, need to newline + | not (isInit wp) && + lenbit > spaceleft = hypsym : "\n" -- put hyphens\n + -- nothing special + | otherwise = "" -- put nothing + in + + oldcs ++ addbefore ++ bit + where currcol = length . last . lines $ ('\n' : oldcs) + + +putWord :: String -> BreakFormat -> String -> String +putWord oldcs bf@(BreakFormat _ _ mhyp) word = + let bit = case mhyp of + (Just hyp) -> hyphenate hyp word + Nothing -> [word] + in + + -- There is a possible optimisation here (check if the word is bigger + -- than the remaining space and pass it as a singleton. Since there + -- wasn't a notable gain in time, I scrapped it. + + case bit of + (ba:[]) -> putBit oldcs bf Single ba -- singleton + (ba:bb:[]) -> let newcs = putBit oldcs bf Init ba in + putBit newcs bf End bb -- pair + (ba:bs) -> let inics = putBit oldcs bf Init ba -- triplet+ + bodcs = foldl f inics (init bs) in + putBit bodcs bf End (last bs) + where f oldcs bit = putBit oldcs bf Mid bit + + +putLine :: String -> BreakFormat -> String -> String +putLine oldcs bf line = + let ws = words line in + foldl f oldcs ws + where f oldcs w = putWord oldcs bf w + + +-- | Breaks a String to make it fit in a certain width. The output is a String, +-- suitable for writing to screen or file. +breakString :: BreakFormat -> String -> String +breakString bf para = unlines $ breakStringLn bf para + +-- | Convenience for @lines $ breakString bf cs@ +breakStringLn :: BreakFormat -> String -> [String] +breakStringLn bf para = + let ls = lines para in + map (putLine "" bf) ls + diff --git a/linebreak.cabal b/linebreak.cabal new file mode 100644 --- /dev/null +++ b/linebreak.cabal @@ -0,0 +1,21 @@ +name: linebreak +version: 0.1.0.1 +synopsis: breaks strings to fit width +description: Simple functions to break a String to fit a maximum text + width, using Knuth-Lian hyphenation algorhitm. +license: BSD3 +license-file: LICENSE +author: Francesco Ariis +maintainer: fa-ml@ariis.it +category: Text +build-type: Simple +cabal-version: >=1.8 + +source-repository head + type: darcs + location: http://www.ariis.it/share/repos/linebreak/ + +library + -- Modules exported by the library. + exposed-modules: Text.LineBreak + build-depends: base ==4.5.*, hyphenation ==0.4.*