polyparse-1.2: docs/haddock/src/Text/Parse.html
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<title>src/Text/Parse.hs</title>
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<pre><a name="line-1"></a><font color=Green><u>module</u></font> Text<font color=Cyan>.</font>Parse
<a name="line-2"></a> <font color=Cyan>(</font> <font color=Blue>-- * The Parse class is a replacement for the standard Read class. </font>
<a name="line-3"></a> <font color=Blue>-- $parser</font>
<a name="line-4"></a> TextParser <font color=Blue>-- synonym for Parser Char, i.e. string input, no state</font>
<a name="line-5"></a> <font color=Cyan>,</font> Parse<font color=Cyan>(</font><font color=Red>..</font><font color=Cyan>)</font> <font color=Blue>-- instances: (), (a,b), (a,b,c), Maybe a, Either a, [a],</font>
<a name="line-6"></a> <font color=Blue>-- Int, Integer, Float, Double, Char, Bool</font>
<a name="line-7"></a> <font color=Cyan>,</font> parseByRead <font color=Blue>-- :: Read a => String -> TextParser a</font>
<a name="line-8"></a> <font color=Blue>-- ** Combinators specific to string input, lexed haskell-style</font>
<a name="line-9"></a> <font color=Cyan>,</font> word <font color=Blue>-- :: TextParser String</font>
<a name="line-10"></a> <font color=Cyan>,</font> isWord <font color=Blue>-- :: String -> TextParser ()</font>
<a name="line-11"></a> <font color=Cyan>,</font> optionalParens <font color=Blue>-- :: TextParser a -> TextParser a</font>
<a name="line-12"></a> <font color=Cyan>,</font> parens <font color=Blue>-- :: Bool -> TextParser a -> TextParser a</font>
<a name="line-13"></a> <font color=Cyan>,</font> field <font color=Blue>-- :: Parse a => String -> TextParser a</font>
<a name="line-14"></a> <font color=Cyan>,</font> constructors<font color=Blue>-- :: [(String,TextParser a)] -> TextParser a</font>
<a name="line-15"></a> <font color=Cyan>,</font> enumeration <font color=Blue>-- :: Show a => String -> [a] -> TextParser a</font>
<a name="line-16"></a> <font color=Blue>-- ** Parsers for literal numerics and characters</font>
<a name="line-17"></a> <font color=Cyan>,</font> parseSigned
<a name="line-18"></a> <font color=Cyan>,</font> parseInt
<a name="line-19"></a> <font color=Cyan>,</font> parseDec
<a name="line-20"></a> <font color=Cyan>,</font> parseOct
<a name="line-21"></a> <font color=Cyan>,</font> parseHex
<a name="line-22"></a> <font color=Cyan>,</font> parseFloat
<a name="line-23"></a> <font color=Cyan>,</font> parseLitChar
<a name="line-24"></a> <font color=Blue>-- ** Re-export all the more general combinators from Poly too</font>
<a name="line-25"></a> <font color=Cyan>,</font> <font color=Green><u>module</u></font> Text<font color=Cyan>.</font>ParserCombinators<font color=Cyan>.</font>Poly
<a name="line-26"></a> <font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="line-27"></a>
<a name="line-28"></a><font color=Green><u>import</u></font> Char <font color=Cyan>(</font>isSpace<font color=Cyan>,</font>toLower<font color=Cyan>,</font>isUpper<font color=Cyan>,</font>isDigit<font color=Cyan>,</font>isOctDigit<font color=Cyan>,</font>isHexDigit<font color=Cyan>,</font>digitToInt
<a name="line-29"></a> <font color=Cyan>,</font>ord<font color=Cyan>,</font>chr<font color=Cyan>)</font>
<a name="line-30"></a><font color=Green><u>import</u></font> List <font color=Cyan>(</font>intersperse<font color=Cyan>)</font>
<a name="line-31"></a><font color=Green><u>import</u></font> Ratio
<a name="line-32"></a><font color=Green><u>import</u></font> Text<font color=Cyan>.</font>ParserCombinators<font color=Cyan>.</font>Poly
<a name="line-33"></a>
<a name="line-34"></a><font color=Blue>------------------------------------------------------------------------</font>
<a name="line-35"></a><font color=Blue>-- $parser</font>
<a name="line-36"></a><font color=Blue>-- The Parse class is a replacement for the standard Read class. It is a</font>
<a name="line-37"></a><font color=Blue>-- specialisation of the (poly) Parser monad for String input.</font>
<a name="line-38"></a><font color=Blue>-- There are instances defined for all Prelude types.</font>
<a name="line-39"></a><font color=Blue>-- For user-defined types, you can write your own instance, or use</font>
<a name="line-40"></a><font color=Blue>-- DrIFT to generate them automatically, e.g. {-! derive : Parse !-}</font>
<a name="line-41"></a>
<a name="line-42"></a><a name="TextParser"></a><font color=Blue>-- | A synonym for Parser Char, i.e. string input (no state)</font>
<a name="line-43"></a><a name="TextParser"></a><font color=Green><u>type</u></font> TextParser a <font color=Red>=</font> Parser Char a
<a name="line-44"></a>
<a name="line-45"></a><a name="Parse"></a><font color=Blue>-- | The class @Parse@ is a replacement for @Read@, operating over String input.</font>
<a name="line-46"></a><a name="Parse"></a><font color=Blue>-- Essentially, it permits better error messages for why something failed to</font>
<a name="line-47"></a><a name="Parse"></a><font color=Blue>-- parse. It is rather important that @parse@ can read back exactly what</font>
<a name="line-48"></a><a name="Parse"></a><font color=Blue>-- is generated by the corresponding instance of @show@. To apply a parser</font>
<a name="line-49"></a><a name="Parse"></a><font color=Blue>-- to some text, use @runParser@.</font>
<a name="line-50"></a><a name="Parse"></a><font color=Green><u>class</u></font> Parse a <font color=Green><u>where</u></font>
<a name="line-51"></a> <font color=Blue>-- | A straightforward parser for an item. (A minimal definition of</font>
<a name="line-52"></a> <font color=Blue>-- a class instance requires either |parse| or |parsePrec|.)</font>
<a name="line-53"></a> parse <font color=Red>::</font> TextParser a
<a name="line-54"></a> parse <font color=Red>=</font> parsePrec <font color=Magenta>0</font>
<a name="line-55"></a> <font color=Blue>-- | A straightforward parser for an item, given the precedence of</font>
<a name="line-56"></a> <font color=Blue>-- any surrounding expression. (Precedence determines whether</font>
<a name="line-57"></a> <font color=Blue>-- parentheses are mandatory or optional.)</font>
<a name="line-58"></a> parsePrec <font color=Red>::</font> Int <font color=Red>-></font> TextParser a
<a name="line-59"></a> parsePrec <font color=Green><u>_</u></font> <font color=Red>=</font> parens False parse
<a name="line-60"></a> <font color=Blue>-- | Parsing a list of items by default accepts the [] and comma syntax,</font>
<a name="line-61"></a> <font color=Blue>-- except when the list is really a character string using \"\".</font>
<a name="line-62"></a> parseList <font color=Red>::</font> TextParser <font color=Red>[</font>a<font color=Red>]</font> <font color=Blue>-- only to distinguish [] and ""</font>
<a name="line-63"></a> parseList <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord <font color=Magenta>"[]"</font><font color=Cyan>;</font> return [] <font color=Cyan>}</font>
<a name="line-64"></a> <font color=Cyan>`onFail`</font>
<a name="line-65"></a> <font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord <font color=Magenta>"["</font><font color=Cyan>;</font> isWord <font color=Magenta>"]"</font><font color=Cyan>;</font> return [] <font color=Cyan>}</font>
<a name="line-66"></a> <font color=Cyan>`onFail`</font>
<a name="line-67"></a> bracketSep <font color=Cyan>(</font>isWord <font color=Magenta>"["</font><font color=Cyan>)</font> <font color=Cyan>(</font>isWord <font color=Magenta>","</font><font color=Cyan>)</font> <font color=Cyan>(</font>isWord <font color=Magenta>"]"</font><font color=Cyan>)</font> parse
<a name="line-68"></a> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Expected a list, but\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-69"></a>
<a name="line-70"></a><a name="parseByRead"></a><font color=Blue>-- | If there already exists a Read instance for a type, then we can make</font>
<a name="line-71"></a><font color=Blue>-- a Parser for it, but with only poor error-reporting. The string argument</font>
<a name="line-72"></a><font color=Blue>-- is the expected type or value (for error-reporting only).</font>
<a name="line-73"></a><font color=Blue>parseByRead</font> <font color=Red>::</font> Read a <font color=Red>=></font> String <font color=Red>-></font> TextParser a
<a name="line-74"></a><font color=Blue>parseByRead</font> name <font color=Red>=</font>
<a name="line-75"></a> P <font color=Cyan>(</font><font color=Red>\</font>s<font color=Red>-></font> <font color=Green><u>case</u></font> reads s <font color=Green><u>of</u></font>
<a name="line-76"></a> [] <font color=Red>-></font> Failure s <font color=Cyan>(</font><font color=Magenta>"no parse, expected a "</font><font color=Cyan>++</font>name<font color=Cyan>)</font>
<a name="line-77"></a> <font color=Red>[</font><font color=Cyan>(</font>a<font color=Cyan>,</font>s'<font color=Cyan>)</font><font color=Red>]</font> <font color=Red>-></font> Success s' a
<a name="line-78"></a> <font color=Green><u>_</u></font> <font color=Red>-></font> Failure s <font color=Cyan>(</font><font color=Magenta>"ambiguous parse, expected a "</font><font color=Cyan>++</font>name<font color=Cyan>)</font>
<a name="line-79"></a> <font color=Cyan>)</font>
<a name="line-80"></a>
<a name="line-81"></a><a name="word"></a><font color=Blue>-- | One lexical chunk (Haskell-style lexing).</font>
<a name="line-82"></a><font color=Blue>word</font> <font color=Red>::</font> TextParser String
<a name="line-83"></a><font color=Blue>word</font> <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s<font color=Red>-></font> <font color=Green><u>case</u></font> lex s <font color=Green><u>of</u></font>
<a name="line-84"></a> [] <font color=Red>-></font> Failure s <font color=Cyan>(</font><font color=Magenta>"no input? (impossible)"</font><font color=Cyan>)</font>
<a name="line-85"></a> <font color=Red>[</font><font color=Cyan>(</font><font color=Magenta>""</font><font color=Cyan>,</font><font color=Magenta>""</font><font color=Cyan>)</font><font color=Red>]</font> <font color=Red>-></font> Failure <font color=Magenta>""</font> <font color=Cyan>(</font><font color=Magenta>"no input?"</font><font color=Cyan>)</font>
<a name="line-86"></a> <font color=Red>[</font><font color=Cyan>(</font><font color=Magenta>""</font><font color=Cyan>,</font>s'<font color=Cyan>)</font><font color=Red>]</font> <font color=Red>-></font> Failure s <font color=Cyan>(</font><font color=Magenta>"lexing failed?"</font><font color=Cyan>)</font>
<a name="line-87"></a> <font color=Cyan>(</font><font color=Cyan>(</font>x<font color=Cyan>,</font>s'<font color=Cyan>)</font><font color=Red><b>:</b></font><font color=Green><u>_</u></font><font color=Cyan>)</font> <font color=Red>-></font> Success s' x
<a name="line-88"></a> <font color=Cyan>)</font>
<a name="line-89"></a>
<a name="line-90"></a><a name="isWord"></a><font color=Blue>-- | Ensure that the next input word is the given string. (Note the input</font>
<a name="line-91"></a><font color=Blue>-- is lexed as haskell, so wordbreaks at spaces, symbols, etc.)</font>
<a name="line-92"></a><font color=Blue>isWord</font> <font color=Red>::</font> String <font color=Red>-></font> TextParser String
<a name="line-93"></a><font color=Blue>isWord</font> w <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> w' <font color=Red><-</font> word
<a name="line-94"></a> <font color=Cyan>;</font> <font color=Green><u>if</u></font> w'<font color=Cyan>==</font>w <font color=Green><u>then</u></font> return w <font color=Green><u>else</u></font> fail <font color=Cyan>(</font><font color=Magenta>"expected "</font><font color=Cyan>++</font>w<font color=Cyan>++</font><font color=Magenta>" got "</font><font color=Cyan>++</font>w'<font color=Cyan>)</font>
<a name="line-95"></a> <font color=Cyan>}</font>
<a name="line-96"></a>
<a name="line-97"></a><a name="optionalParens"></a><font color=Blue>-- | Allow true string parens around an item.</font>
<a name="line-98"></a><font color=Blue>optionalParens</font> <font color=Red>::</font> TextParser a <font color=Red>-></font> TextParser a
<a name="line-99"></a><font color=Blue>optionalParens</font> p <font color=Red>=</font> bracket <font color=Cyan>(</font>isWord <font color=Magenta>"("</font><font color=Cyan>)</font> <font color=Cyan>(</font>isWord <font color=Magenta>")"</font><font color=Cyan>)</font> p <font color=Cyan>`onFail`</font> p
<a name="line-100"></a>
<a name="line-101"></a><a name="parens"></a><font color=Blue>-- | Allow nested parens around an item (one set required when Bool is True).</font>
<a name="line-102"></a><font color=Blue>parens</font> <font color=Red>::</font> Bool <font color=Red>-></font> TextParser a <font color=Red>-></font> TextParser a
<a name="line-103"></a><font color=Blue>parens</font> True p <font color=Red>=</font> bracket <font color=Cyan>(</font>isWord <font color=Magenta>"("</font><font color=Cyan>)</font> <font color=Cyan>(</font>isWord <font color=Magenta>")"</font><font color=Cyan>)</font> <font color=Cyan>(</font>parens False p<font color=Cyan>)</font>
<a name="line-104"></a><font color=Blue>parens</font> False p <font color=Red>=</font> parens True p <font color=Cyan>`onFail`</font> p
<a name="line-105"></a>
<a name="line-106"></a><a name="field"></a><font color=Blue>-- | Deal with named field syntax. The string argument is the field name,</font>
<a name="line-107"></a><font color=Blue>-- and the parser returns the value of the field.</font>
<a name="line-108"></a><font color=Blue>field</font> <font color=Red>::</font> Parse a <font color=Red>=></font> String <font color=Red>-></font> TextParser a
<a name="line-109"></a><font color=Blue>field</font> name <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord name<font color=Cyan>;</font> commit <font color=Cyan>$</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord <font color=Magenta>"="</font><font color=Cyan>;</font> parse <font color=Cyan>}</font> <font color=Cyan>}</font>
<a name="line-110"></a>
<a name="line-111"></a><a name="constructors"></a><font color=Blue>-- | Parse one of a bunch of alternative constructors. In the list argument,</font>
<a name="line-112"></a><font color=Blue>-- the first element of the pair is the constructor name, and</font>
<a name="line-113"></a><font color=Blue>-- the second is the parser for the rest of the value. The first matching</font>
<a name="line-114"></a><font color=Blue>-- parse is returned.</font>
<a name="line-115"></a><font color=Blue>constructors</font> <font color=Red>::</font> <font color=Red>[</font><font color=Cyan>(</font>String<font color=Cyan>,</font>TextParser a<font color=Cyan>)</font><font color=Red>]</font> <font color=Red>-></font> TextParser a
<a name="line-116"></a><font color=Blue>constructors</font> cs <font color=Red>=</font> oneOf' <font color=Cyan>(</font>map cons cs<font color=Cyan>)</font>
<a name="line-117"></a> <font color=Green><u>where</u></font> cons <font color=Cyan>(</font>name<font color=Cyan>,</font>p<font color=Cyan>)</font> <font color=Red>=</font>
<a name="line-118"></a> <font color=Cyan>(</font> name
<a name="line-119"></a> <font color=Cyan>,</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord name
<a name="line-120"></a> <font color=Cyan>;</font> p <font color=Cyan>`adjustErrBad`</font> <font color=Cyan>(</font><font color=Cyan>(</font><font color=Magenta>"got constructor, but within "</font>
<a name="line-121"></a> <font color=Cyan>++</font>name<font color=Cyan>++</font><font color=Magenta>",\n"</font><font color=Cyan>)</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-122"></a> <font color=Cyan>}</font>
<a name="line-123"></a> <font color=Cyan>)</font>
<a name="line-124"></a>
<a name="line-125"></a><font color=Blue>{-
<a name="line-126"></a>-- | Parse an infix constructor.
<a name="line-127"></a>infixConstructor :: (Parse a, Parse b) =>
<a name="line-128"></a> String -> Int -> (a->b->c) -> Int -> TextParser c
<a name="line-129"></a>infixConstructor name prec cons = \d->
<a name="line-130"></a> parens (prec<d) (do a <- parsePrec (prec+1)
<a name="line-131"></a> isWord name `adjustErr`
<a name="line-132"></a> (++("expected infix constructor "++name))
<a name="line-133"></a> b <- parsePrec (prec+1)
<a name="line-134"></a> return (cons a b) )
<a name="line-135"></a>
<a name="line-136"></a>--infixLeftAssoc :: (Parse a, Parse b) =>
<a name="line-137"></a>-- String -> Int -> (a->b->a) -> Int -> TextParser a
<a name="line-138"></a>--infixLeftAssoc name prec cons = \d->
<a name="line-139"></a>-- parens (prec<d) (do a <-
<a name="line-140"></a>-}</font>
<a name="line-141"></a>
<a name="line-142"></a><a name="enumeration"></a><font color=Blue>-- | Parse one of the given nullary constructors (an enumeration).</font>
<a name="line-143"></a><font color=Blue>-- The string argument is the name of the type, and the list argument</font>
<a name="line-144"></a><font color=Blue>-- should contain all of the possible enumeration values.</font>
<a name="line-145"></a><font color=Blue>enumeration</font> <font color=Red>::</font> <font color=Cyan>(</font>Show a<font color=Cyan>)</font> <font color=Red>=></font> String <font color=Red>-></font> <font color=Red>[</font>a<font color=Red>]</font> <font color=Red>-></font> TextParser a
<a name="line-146"></a><font color=Blue>enumeration</font> typ cs <font color=Red>=</font> oneOf <font color=Cyan>(</font>map <font color=Cyan>(</font><font color=Red>\</font>c<font color=Red>-></font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord <font color=Cyan>(</font>show c<font color=Cyan>)</font><font color=Cyan>;</font> return c <font color=Cyan>}</font><font color=Cyan>)</font> cs<font color=Cyan>)</font>
<a name="line-147"></a> <font color=Cyan>`adjustErr`</font>
<a name="line-148"></a> <font color=Cyan>(</font><font color=Cyan>++</font><font color=Cyan>(</font><font color=Magenta>"\n expected "</font><font color=Cyan>++</font>typ<font color=Cyan>++</font><font color=Magenta>" value ("</font><font color=Cyan>++</font>e<font color=Cyan>++</font><font color=Magenta>")"</font><font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-149"></a> <font color=Green><u>where</u></font> e <font color=Red>=</font> concat <font color=Cyan>(</font>intersperse <font color=Magenta>", "</font> <font color=Cyan>(</font>map show <font color=Cyan>(</font>init cs<font color=Cyan>)</font><font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-150"></a> <font color=Cyan>++</font> <font color=Magenta>", or "</font> <font color=Cyan>++</font> show <font color=Cyan>(</font>last cs<font color=Cyan>)</font>
<a name="line-151"></a>
<a name="line-152"></a><font color=Blue>------------------------------------------------------------------------</font>
<a name="line-153"></a><font color=Blue>-- Instances for all the Standard Prelude types.</font>
<a name="line-154"></a>
<a name="line-155"></a><a name="parseSigned"></a><font color=Blue>-- Numeric types</font>
<a name="line-156"></a><font color=Blue>parseSigned</font> <font color=Red>::</font> Real a <font color=Red>=></font> TextParser a <font color=Red>-></font> TextParser a
<a name="line-157"></a><font color=Blue>parseSigned</font> p <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'-'</font> <font color=Red><-</font> next<font color=Cyan>;</font> commit <font color=Cyan>(</font>fmap negate p<font color=Cyan>)</font>
<a name="line-158"></a> <font color=Cyan>`onFail`</font>
<a name="line-159"></a> <font color=Green><u>do</u></font> p
<a name="line-160"></a>
<a name="line-161"></a><a name="parseInt"></a><font color=Blue>parseInt</font> <font color=Red>::</font> <font color=Cyan>(</font>Integral a<font color=Cyan>)</font> <font color=Red>=></font> String <font color=Red>-></font>
<a name="line-162"></a> a <font color=Red>-></font> <font color=Cyan>(</font>Char <font color=Red>-></font> Bool<font color=Cyan>)</font> <font color=Red>-></font> <font color=Cyan>(</font>Char <font color=Red>-></font> Int<font color=Cyan>)</font> <font color=Red>-></font>
<a name="line-163"></a> a <font color=Red>-></font> TextParser a
<a name="line-164"></a><font color=Blue>parseInt</font> base radix isDigit digitToInt n <font color=Red>=</font> go n
<a name="line-165"></a> <font color=Green><u>where</u></font> go acc <font color=Red>=</font> <font color=Green><u>do</u></font> cs <font color=Red><-</font> many1 <font color=Cyan>(</font>satisfy isDigit<font color=Cyan>)</font>
<a name="line-166"></a> return <font color=Cyan>(</font>foldl1 <font color=Cyan>(</font><font color=Red>\</font>n d<font color=Red>-></font> n<font color=Cyan>*</font>radix<font color=Cyan>+</font>d<font color=Cyan>)</font>
<a name="line-167"></a> <font color=Cyan>(</font>map <font color=Cyan>(</font>fromIntegral<font color=Cyan>.</font>digitToInt<font color=Cyan>)</font> cs<font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-168"></a> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Cyan>++</font><font color=Cyan>(</font><font color=Magenta>"\nexpected one or more "</font><font color=Cyan>++</font>base<font color=Cyan>++</font><font color=Magenta>" digits"</font><font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-169"></a><a name="parseDec"></a><font color=Blue>parseDec</font><font color=Cyan>,</font> parseOct<font color=Cyan>,</font> parseHex <font color=Red>::</font> <font color=Cyan>(</font>Integral a<font color=Cyan>)</font> <font color=Red>=></font> a <font color=Red>-></font> TextParser a
<a name="line-170"></a><font color=Blue>parseDec</font> <font color=Red>=</font> parseInt <font color=Magenta>"decimal"</font> <font color=Magenta>10</font> Char<font color=Cyan>.</font>isDigit Char<font color=Cyan>.</font>digitToInt
<a name="line-171"></a><a name="parseOct"></a><font color=Blue>parseOct</font> <font color=Red>=</font> parseInt <font color=Magenta>"octal"</font> <font color=Magenta>8</font> Char<font color=Cyan>.</font>isOctDigit Char<font color=Cyan>.</font>digitToInt
<a name="line-172"></a><a name="parseHex"></a><font color=Blue>parseHex</font> <font color=Red>=</font> parseInt <font color=Magenta>"hex"</font> <font color=Magenta>16</font> Char<font color=Cyan>.</font>isHexDigit Char<font color=Cyan>.</font>digitToInt
<a name="line-173"></a>
<a name="line-174"></a><a name="parseFloat"></a><font color=Blue>parseFloat</font> <font color=Red>::</font> <font color=Cyan>(</font>RealFrac a<font color=Cyan>)</font> <font color=Red>=></font> TextParser a
<a name="line-175"></a><font color=Blue>parseFloat</font> <font color=Red>=</font> <font color=Green><u>do</u></font> ds <font color=Red><-</font> many1 <font color=Cyan>(</font>satisfy isDigit<font color=Cyan>)</font>
<a name="line-176"></a> frac <font color=Red><-</font> <font color=Cyan>(</font><font color=Green><u>do</u></font> <font color=Magenta>'.'</font> <font color=Red><-</font> next
<a name="line-177"></a> many <font color=Cyan>(</font>satisfy isDigit<font color=Cyan>)</font>
<a name="line-178"></a> <font color=Cyan>`adjustErrBad`</font> <font color=Cyan>(</font><font color=Cyan>++</font><font color=Magenta>"expected digit after ."</font><font color=Cyan>)</font>
<a name="line-179"></a> <font color=Cyan>`onFail`</font> return [] <font color=Cyan>)</font>
<a name="line-180"></a> exp <font color=Red><-</font> <font color=Cyan>(</font><font color=Green><u>do</u></font> <font color=Magenta>'e'</font> <font color=Red><-</font> fmap toLower next
<a name="line-181"></a> commit <font color=Cyan>(</font><font color=Green><u>do</u></font> <font color=Magenta>'+'</font> <font color=Red><-</font> next<font color=Cyan>;</font> parseDec <font color=Magenta>0</font>
<a name="line-182"></a> <font color=Cyan>`onFail`</font>
<a name="line-183"></a> parseSigned <font color=Cyan>(</font>parseDec <font color=Magenta>0</font><font color=Cyan>)</font> <font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-184"></a> <font color=Cyan>(</font> return <font color=Cyan>.</font> fromRational <font color=Cyan>.</font> <font color=Cyan>(</font><font color=Cyan>*</font> <font color=Cyan>(</font><font color=Magenta>10</font><font color=Cyan>^^</font><font color=Cyan>(</font>exp <font color=Blue>-</font> length frac<font color=Cyan>)</font><font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-185"></a> <font color=Cyan>.</font> <font color=Cyan>(</font><font color=Cyan>%</font><font color=Magenta>1</font><font color=Cyan>)</font> <font color=Cyan>.</font> <font color=Cyan>(</font><font color=Red>\</font> <font color=Cyan>(</font>Right x<font color=Cyan>)</font><font color=Red>-></font>x<font color=Cyan>)</font> <font color=Cyan>.</font> fst
<a name="line-186"></a> <font color=Cyan>.</font> runParser <font color=Cyan>(</font>parseDec <font color=Magenta>0</font><font color=Cyan>)</font> <font color=Cyan>)</font> <font color=Cyan>(</font>ds<font color=Cyan>++</font>frac<font color=Cyan>)</font>
<a name="line-187"></a> <font color=Cyan>`onFail`</font>
<a name="line-188"></a> <font color=Green><u>do</u></font> w <font color=Red><-</font> many <font color=Cyan>(</font>satisfy <font color=Cyan>(</font>not<font color=Cyan>.</font>isSpace<font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-189"></a> <font color=Green><u>case</u></font> map toLower w <font color=Green><u>of</u></font>
<a name="line-190"></a> <font color=Magenta>"nan"</font> <font color=Red>-></font> return <font color=Cyan>(</font><font color=Magenta>0</font><font color=Cyan>/</font><font color=Magenta>0</font><font color=Cyan>)</font>
<a name="line-191"></a> <font color=Magenta>"infinity"</font> <font color=Red>-></font> return <font color=Cyan>(</font><font color=Magenta>1</font><font color=Cyan>/</font><font color=Magenta>0</font><font color=Cyan>)</font>
<a name="line-192"></a> <font color=Green><u>_</u></font> <font color=Red>-></font> fail <font color=Magenta>"expected a floating point number"</font>
<a name="line-193"></a>
<a name="line-194"></a><a name="parseLitChar"></a><font color=Blue>parseLitChar</font> <font color=Red>::</font> TextParser Char
<a name="line-195"></a><font color=Blue>parseLitChar</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'\''</font> <font color=Red><-</font> next <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Cyan>++</font><font color=Magenta>"expected a literal char"</font><font color=Cyan>)</font>
<a name="line-196"></a> c <font color=Red><-</font> next
<a name="line-197"></a> char <font color=Red><-</font> <font color=Green><u>case</u></font> c <font color=Green><u>of</u></font>
<a name="line-198"></a> <font color=Magenta>'\\'</font> <font color=Red>-></font> next <font color=Cyan>>>=</font> escape
<a name="line-199"></a> <font color=Magenta>'\''</font> <font color=Red>-></font> fail <font color=Magenta>"expected a literal char, got ''"</font>
<a name="line-200"></a> <font color=Green><u>_</u></font> <font color=Red>-></font> return c
<a name="line-201"></a> <font color=Magenta>'\''</font> <font color=Red><-</font> next <font color=Cyan>`adjustErrBad`</font> <font color=Cyan>(</font><font color=Cyan>++</font><font color=Magenta>"literal char has no final '"</font><font color=Cyan>)</font>
<a name="line-202"></a> return char
<a name="line-203"></a> <font color=Green><u>where</u></font>
<a name="line-204"></a> escape <font color=Magenta>'a'</font> <font color=Red>=</font> return <font color=Magenta>'\a'</font>
<a name="line-205"></a> escape <font color=Magenta>'b'</font> <font color=Red>=</font> return <font color=Magenta>'\b'</font>
<a name="line-206"></a> escape <font color=Magenta>'f'</font> <font color=Red>=</font> return <font color=Magenta>'\f'</font>
<a name="line-207"></a> escape <font color=Magenta>'n'</font> <font color=Red>=</font> return <font color=Magenta>'\n'</font>
<a name="line-208"></a> escape <font color=Magenta>'r'</font> <font color=Red>=</font> return <font color=Magenta>'\r'</font>
<a name="line-209"></a> escape <font color=Magenta>'t'</font> <font color=Red>=</font> return <font color=Magenta>'\t'</font>
<a name="line-210"></a> escape <font color=Magenta>'v'</font> <font color=Red>=</font> return <font color=Magenta>'\v'</font>
<a name="line-211"></a> escape <font color=Magenta>'\\'</font> <font color=Red>=</font> return <font color=Magenta>'\\'</font>
<a name="line-212"></a> escape <font color=Magenta>'"'</font> <font color=Red>=</font> return <font color=Magenta>'"'</font>
<a name="line-213"></a> escape <font color=Magenta>'\''</font> <font color=Red>=</font> return <font color=Magenta>'\''</font>
<a name="line-214"></a> escape <font color=Magenta>'^'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> ctrl <font color=Red><-</font> next
<a name="line-215"></a> <font color=Green><u>if</u></font> ctrl <font color=Cyan>>=</font> <font color=Magenta>'@'</font> <font color=Cyan>&&</font> ctrl <font color=Cyan><=</font> <font color=Magenta>'_'</font>
<a name="line-216"></a> <font color=Green><u>then</u></font> return <font color=Cyan>(</font>chr <font color=Cyan>(</font>ord ctrl <font color=Blue>-</font> ord <font color=Magenta>'@'</font><font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-217"></a> <font color=Green><u>else</u></font> fail <font color=Cyan>(</font><font color=Magenta>"literal char ctrl-escape malformed: \\^"</font>
<a name="line-218"></a> <font color=Cyan>++</font><font color=Red>[</font>ctrl<font color=Red>]</font><font color=Cyan>)</font>
<a name="line-219"></a> escape d <font color=Red>|</font> isDigit d
<a name="line-220"></a> <font color=Red>=</font> fmap chr <font color=Cyan>$</font> parseDec <font color=Cyan>(</font>Char<font color=Cyan>.</font>digitToInt d<font color=Cyan>)</font>
<a name="line-221"></a> escape <font color=Magenta>'o'</font> <font color=Red>=</font> fmap chr <font color=Cyan>$</font> parseOct <font color=Magenta>0</font>
<a name="line-222"></a> escape <font color=Magenta>'x'</font> <font color=Red>=</font> fmap chr <font color=Cyan>$</font> parseHex <font color=Magenta>0</font>
<a name="line-223"></a> escape c <font color=Red>|</font> isUpper c
<a name="line-224"></a> <font color=Red>=</font> mnemonic c
<a name="line-225"></a> escape c <font color=Red>=</font> fail <font color=Cyan>(</font><font color=Magenta>"unrecognised escape sequence in literal char: \\"</font><font color=Cyan>++</font><font color=Red>[</font>c<font color=Red>]</font><font color=Cyan>)</font>
<a name="line-226"></a>
<a name="line-227"></a> mnemonic <font color=Magenta>'A'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'C'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'K'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\ACK'</font>
<a name="line-228"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\ACK'"</font>
<a name="line-229"></a> mnemonic <font color=Magenta>'B'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'E'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'L'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\BEL'</font>
<a name="line-230"></a> <font color=Cyan>`onFail`</font>
<a name="line-231"></a> <font color=Green><u>do</u></font> <font color=Magenta>'S'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\BS'</font>
<a name="line-232"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\BEL' or '\\BS'"</font>
<a name="line-233"></a> mnemonic <font color=Magenta>'C'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'R'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\CR'</font>
<a name="line-234"></a> <font color=Cyan>`onFail`</font>
<a name="line-235"></a> <font color=Green><u>do</u></font> <font color=Magenta>'A'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'N'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\CAN'</font>
<a name="line-236"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\CR' or '\\CAN'"</font>
<a name="line-237"></a> mnemonic <font color=Magenta>'D'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'E'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'L'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\DEL'</font>
<a name="line-238"></a> <font color=Cyan>`onFail`</font>
<a name="line-239"></a> <font color=Green><u>do</u></font> <font color=Magenta>'L'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'E'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\DLE'</font>
<a name="line-240"></a> <font color=Cyan>`onFail`</font>
<a name="line-241"></a> <font color=Green><u>do</u></font> <font color=Magenta>'C'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Cyan>(</font> <font color=Green><u>do</u></font> <font color=Magenta>'1'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\DC1'</font>
<a name="line-242"></a> <font color=Cyan>`onFail`</font>
<a name="line-243"></a> <font color=Green><u>do</u></font> <font color=Magenta>'2'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\DC2'</font>
<a name="line-244"></a> <font color=Cyan>`onFail`</font>
<a name="line-245"></a> <font color=Green><u>do</u></font> <font color=Magenta>'3'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\DC3'</font>
<a name="line-246"></a> <font color=Cyan>`onFail`</font>
<a name="line-247"></a> <font color=Green><u>do</u></font> <font color=Magenta>'4'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\DC4'</font> <font color=Cyan>)</font>
<a name="line-248"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\DEL' or '\\DLE' or '\\DC[1..4]'"</font>
<a name="line-249"></a> mnemonic <font color=Magenta>'E'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'T'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'X'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\ETX'</font>
<a name="line-250"></a> <font color=Cyan>`onFail`</font>
<a name="line-251"></a> <font color=Green><u>do</u></font> <font color=Magenta>'O'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'T'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\EOT'</font>
<a name="line-252"></a> <font color=Cyan>`onFail`</font>
<a name="line-253"></a> <font color=Green><u>do</u></font> <font color=Magenta>'N'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'Q'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\ENQ'</font>
<a name="line-254"></a> <font color=Cyan>`onFail`</font>
<a name="line-255"></a> <font color=Green><u>do</u></font> <font color=Magenta>'T'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'B'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\ETB'</font>
<a name="line-256"></a> <font color=Cyan>`onFail`</font>
<a name="line-257"></a> <font color=Green><u>do</u></font> <font color=Magenta>'M'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\EM'</font>
<a name="line-258"></a> <font color=Cyan>`onFail`</font>
<a name="line-259"></a> <font color=Green><u>do</u></font> <font color=Magenta>'S'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'C'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\ESC'</font>
<a name="line-260"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"one of '\\ETX' '\\EOT' '\\ENQ' '\\ETB' '\\EM' or '\\ESC'"</font>
<a name="line-261"></a> mnemonic <font color=Magenta>'F'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'F'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\FF'</font>
<a name="line-262"></a> <font color=Cyan>`onFail`</font>
<a name="line-263"></a> <font color=Green><u>do</u></font> <font color=Magenta>'S'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\FS'</font>
<a name="line-264"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\FF' or '\\FS'"</font>
<a name="line-265"></a> mnemonic <font color=Magenta>'G'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'S'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\GS'</font>
<a name="line-266"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\GS'"</font>
<a name="line-267"></a> mnemonic <font color=Magenta>'H'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'T'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\HT'</font>
<a name="line-268"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\HT'"</font>
<a name="line-269"></a> mnemonic <font color=Magenta>'L'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'F'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\LF'</font>
<a name="line-270"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\LF'"</font>
<a name="line-271"></a> mnemonic <font color=Magenta>'N'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'U'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'L'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\NUL'</font>
<a name="line-272"></a> <font color=Cyan>`onFail`</font>
<a name="line-273"></a> <font color=Green><u>do</u></font> <font color=Magenta>'A'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'K'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\NAK'</font>
<a name="line-274"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\NUL' or '\\NAK'"</font>
<a name="line-275"></a> mnemonic <font color=Magenta>'R'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'S'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\RS'</font>
<a name="line-276"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\RS'"</font>
<a name="line-277"></a> mnemonic <font color=Magenta>'S'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'O'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'H'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\SOH'</font>
<a name="line-278"></a> <font color=Cyan>`onFail`</font>
<a name="line-279"></a> <font color=Green><u>do</u></font> <font color=Magenta>'O'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\SO'</font>
<a name="line-280"></a> <font color=Cyan>`onFail`</font>
<a name="line-281"></a> <font color=Green><u>do</u></font> <font color=Magenta>'T'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'X'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\STX'</font>
<a name="line-282"></a> <font color=Cyan>`onFail`</font>
<a name="line-283"></a> <font color=Green><u>do</u></font> <font color=Magenta>'I'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\SI'</font>
<a name="line-284"></a> <font color=Cyan>`onFail`</font>
<a name="line-285"></a> <font color=Green><u>do</u></font> <font color=Magenta>'Y'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'N'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\SYN'</font>
<a name="line-286"></a> <font color=Cyan>`onFail`</font>
<a name="line-287"></a> <font color=Green><u>do</u></font> <font color=Magenta>'U'</font> <font color=Red><-</font> next<font color=Cyan>;</font> <font color=Magenta>'B'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\SUB'</font>
<a name="line-288"></a> <font color=Cyan>`onFail`</font>
<a name="line-289"></a> <font color=Green><u>do</u></font> <font color=Magenta>'P'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\SP'</font>
<a name="line-290"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\SOH' '\\SO' '\\STX' '\\SI' '\\SYN' '\\SUB' or '\\SP'"</font>
<a name="line-291"></a> mnemonic <font color=Magenta>'U'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'S'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\US'</font>
<a name="line-292"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\US'"</font>
<a name="line-293"></a> mnemonic <font color=Magenta>'V'</font> <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Magenta>'T'</font> <font color=Red><-</font> next<font color=Cyan>;</font> return <font color=Magenta>'\VT'</font>
<a name="line-294"></a> <font color=Cyan>`wrap`</font> <font color=Magenta>"'\\VT'"</font>
<a name="line-295"></a> wrap p s <font color=Red>=</font> p <font color=Cyan>`onFail`</font> fail <font color=Cyan>(</font><font color=Magenta>"expected literal char "</font><font color=Cyan>++</font>s<font color=Cyan>)</font>
<a name="line-296"></a>
<a name="line-297"></a><font color=Blue>-- Basic types</font>
<a name="line-298"></a><font color=Green><u>instance</u></font> Parse Int <font color=Green><u>where</u></font>
<a name="line-299"></a> <font color=Blue>-- parse = parseByRead "Int" -- convert from Integer, deals with minInt</font>
<a name="line-300"></a> parse <font color=Red>=</font> fmap fromInteger <font color=Cyan>$</font>
<a name="line-301"></a> <font color=Green><u>do</u></font> many <font color=Cyan>(</font>satisfy isSpace<font color=Cyan>)</font><font color=Cyan>;</font> parseSigned <font color=Cyan>(</font>parseDec <font color=Magenta>0</font><font color=Cyan>)</font>
<a name="line-302"></a><font color=Green><u>instance</u></font> Parse Integer <font color=Green><u>where</u></font>
<a name="line-303"></a> <font color=Blue>-- parse = parseByRead "Integer"</font>
<a name="line-304"></a> parse <font color=Red>=</font> <font color=Green><u>do</u></font> many <font color=Cyan>(</font>satisfy isSpace<font color=Cyan>)</font><font color=Cyan>;</font> parseSigned <font color=Cyan>(</font>parseDec <font color=Magenta>0</font><font color=Cyan>)</font>
<a name="line-305"></a><font color=Green><u>instance</u></font> Parse Float <font color=Green><u>where</u></font>
<a name="line-306"></a> <font color=Blue>-- parse = parseByRead "Float"</font>
<a name="line-307"></a> parse <font color=Red>=</font> <font color=Green><u>do</u></font> many <font color=Cyan>(</font>satisfy isSpace<font color=Cyan>)</font><font color=Cyan>;</font> parseSigned parseFloat
<a name="line-308"></a><font color=Green><u>instance</u></font> Parse Double <font color=Green><u>where</u></font>
<a name="line-309"></a> <font color=Blue>-- parse = parseByRead "Double"</font>
<a name="line-310"></a> parse <font color=Red>=</font> <font color=Green><u>do</u></font> many <font color=Cyan>(</font>satisfy isSpace<font color=Cyan>)</font><font color=Cyan>;</font> parseSigned parseFloat
<a name="line-311"></a><font color=Green><u>instance</u></font> Parse Char <font color=Green><u>where</u></font>
<a name="line-312"></a><font color=Blue>-- parse = parseByRead "Char"</font>
<a name="line-313"></a> parse <font color=Red>=</font> <font color=Green><u>do</u></font> many <font color=Cyan>(</font>satisfy isSpace<font color=Cyan>)</font><font color=Cyan>;</font> parseLitChar
<a name="line-314"></a> <font color=Blue>-- parse = do { w <- word; if head w == '\'' then readLitChar (tail w)</font>
<a name="line-315"></a> <font color=Blue>-- else fail "expected a char" }</font>
<a name="line-316"></a> <font color=Blue>-- parseList = bracket (isWord "\"") (satisfy (=='"'))</font>
<a name="line-317"></a> <font color=Blue>-- (many (satisfy (/='"')))</font>
<a name="line-318"></a> <font color=Blue>-- not totally correct for strings...</font>
<a name="line-319"></a> parseList <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> w <font color=Red><-</font> word<font color=Cyan>;</font> <font color=Green><u>if</u></font> head w <font color=Cyan>==</font> <font color=Magenta>'"'</font> <font color=Green><u>then</u></font> return <font color=Cyan>(</font>init <font color=Cyan>(</font>tail w<font color=Cyan>)</font><font color=Cyan>)</font>
<a name="line-320"></a> <font color=Green><u>else</u></font> fail <font color=Magenta>"not a string"</font> <font color=Cyan>}</font>
<a name="line-321"></a>
<a name="line-322"></a><font color=Green><u>instance</u></font> Parse Bool <font color=Green><u>where</u></font>
<a name="line-323"></a> parse <font color=Red>=</font> enumeration <font color=Magenta>"Bool"</font> <font color=Red>[</font>False<font color=Cyan>,</font>True<font color=Red>]</font>
<a name="line-324"></a>
<a name="line-325"></a><font color=Green><u>instance</u></font> Parse Ordering <font color=Green><u>where</u></font>
<a name="line-326"></a> parse <font color=Red>=</font> enumeration <font color=Magenta>"Ordering"</font> <font color=Red>[</font>LT<font color=Cyan>,</font>EQ<font color=Cyan>,</font>GT<font color=Red>]</font>
<a name="line-327"></a>
<a name="line-328"></a><font color=Blue>-- Structural types</font>
<a name="line-329"></a><font color=Green><u>instance</u></font> Parse () <font color=Green><u>where</u></font>
<a name="line-330"></a> parse <font color=Red>=</font> P p
<a name="line-331"></a> <font color=Green><u>where</u></font> p [] <font color=Red>=</font> Failure [] <font color=Magenta>"no input: expected a ()"</font>
<a name="line-332"></a> p <font color=Cyan>(</font><font color=Magenta>'('</font><font color=Red><b>:</b></font>cs<font color=Cyan>)</font> <font color=Red>=</font> <font color=Green><u>case</u></font> dropWhile isSpace cs <font color=Green><u>of</u></font>
<a name="line-333"></a> <font color=Cyan>(</font><font color=Magenta>')'</font><font color=Red><b>:</b></font>s<font color=Cyan>)</font> <font color=Red>-></font> Success s ()
<a name="line-334"></a> <font color=Green><u>_</u></font> <font color=Red>-></font> Failure cs <font color=Magenta>"Expected ) after ("</font>
<a name="line-335"></a> p <font color=Cyan>(</font>c<font color=Red><b>:</b></font>cs<font color=Cyan>)</font> <font color=Red>|</font> isSpace c <font color=Red>=</font> p cs
<a name="line-336"></a> <font color=Red>|</font> otherwise <font color=Red>=</font> Failure <font color=Cyan>(</font>c<font color=Red><b>:</b></font>cs<font color=Cyan>)</font> <font color=Cyan>(</font><font color=Magenta>"Expected a (), got "</font><font color=Cyan>++</font>show c<font color=Cyan>)</font>
<a name="line-337"></a>
<a name="line-338"></a><font color=Green><u>instance</u></font> <font color=Cyan>(</font>Parse a<font color=Cyan>,</font> Parse b<font color=Cyan>)</font> <font color=Red>=></font> Parse <font color=Cyan>(</font>a<font color=Cyan>,</font>b<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="line-339"></a> parse <font color=Red>=</font> <font color=Green><u>do</u></font><font color=Cyan>{</font> isWord <font color=Magenta>"("</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Opening a 2-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-340"></a> <font color=Cyan>;</font> x <font color=Red><-</font> parse <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"In 1st item of a 2-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-341"></a> <font color=Cyan>;</font> isWord <font color=Magenta>","</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Separating a 2-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-342"></a> <font color=Cyan>;</font> y <font color=Red><-</font> parse <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"In 2nd item of a 2-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-343"></a> <font color=Cyan>;</font> isWord <font color=Magenta>")"</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Closing a 2-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-344"></a> <font color=Cyan>;</font> return <font color=Cyan>(</font>x<font color=Cyan>,</font>y<font color=Cyan>)</font> <font color=Cyan>}</font>
<a name="line-345"></a>
<a name="line-346"></a><font color=Green><u>instance</u></font> <font color=Cyan>(</font>Parse a<font color=Cyan>,</font> Parse b<font color=Cyan>,</font> Parse c<font color=Cyan>)</font> <font color=Red>=></font> Parse <font color=Cyan>(</font>a<font color=Cyan>,</font>b<font color=Cyan>,</font>c<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="line-347"></a> parse <font color=Red>=</font> <font color=Green><u>do</u></font><font color=Cyan>{</font> isWord <font color=Magenta>"("</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Opening a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-348"></a> <font color=Cyan>;</font> x <font color=Red><-</font> parse <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"In 1st item of a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-349"></a> <font color=Cyan>;</font> isWord <font color=Magenta>","</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Separating(1) a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-350"></a> <font color=Cyan>;</font> y <font color=Red><-</font> parse <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"In 2nd item of a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-351"></a> <font color=Cyan>;</font> isWord <font color=Magenta>","</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Separating(2) a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-352"></a> <font color=Cyan>;</font> z <font color=Red><-</font> parse <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"In 3rd item of a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-353"></a> <font color=Cyan>;</font> isWord <font color=Magenta>")"</font> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Magenta>"Closing a 3-tuple\n"</font><font color=Cyan>++</font><font color=Cyan>)</font>
<a name="line-354"></a> <font color=Cyan>;</font> return <font color=Cyan>(</font>x<font color=Cyan>,</font>y<font color=Cyan>,</font>z<font color=Cyan>)</font> <font color=Cyan>}</font>
<a name="line-355"></a>
<a name="line-356"></a><font color=Green><u>instance</u></font> Parse a <font color=Red>=></font> Parse <font color=Cyan>(</font>Maybe a<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="line-357"></a> parsePrec p <font color=Red>=</font>
<a name="line-358"></a> parens False <font color=Cyan>(</font><font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord <font color=Magenta>"Nothing"</font><font color=Cyan>;</font> return Nothing <font color=Cyan>}</font><font color=Cyan>)</font>
<a name="line-359"></a> <font color=Cyan>`onFail`</font>
<a name="line-360"></a> parens <font color=Cyan>(</font>p<font color=Cyan>></font><font color=Magenta>9</font><font color=Cyan>)</font> <font color=Cyan>(</font><font color=Green><u>do</u></font> <font color=Cyan>{</font> isWord <font color=Magenta>"Just"</font>
<a name="line-361"></a> <font color=Cyan>;</font> fmap Just <font color=Cyan>$</font> parsePrec <font color=Magenta>10</font>
<a name="line-362"></a> <font color=Cyan>`adjustErrBad`</font> <font color=Cyan>(</font><font color=Magenta>"but within Just, "</font><font color=Cyan>++</font><font color=Cyan>)</font> <font color=Cyan>}</font><font color=Cyan>)</font>
<a name="line-363"></a> <font color=Cyan>`adjustErr`</font> <font color=Cyan>(</font><font color=Cyan>(</font><font color=Magenta>"expected a Maybe (Just or Nothing)\n"</font><font color=Cyan>++</font><font color=Cyan>)</font><font color=Cyan>.</font>indent <font color=Magenta>2</font><font color=Cyan>)</font>
<a name="line-364"></a>
<a name="line-365"></a><font color=Green><u>instance</u></font> <font color=Cyan>(</font>Parse a<font color=Cyan>,</font> Parse b<font color=Cyan>)</font> <font color=Red>=></font> Parse <font color=Cyan>(</font>Either a b<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="line-366"></a> parsePrec p <font color=Red>=</font>
<a name="line-367"></a> parens <font color=Cyan>(</font>p<font color=Cyan>></font><font color=Magenta>9</font><font color=Cyan>)</font> <font color=Cyan>$</font>
<a name="line-368"></a> constructors <font color=Red>[</font> <font color=Cyan>(</font><font color=Magenta>"Left"</font><font color=Cyan>,</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> fmap Left <font color=Cyan>$</font> parsePrec <font color=Magenta>10</font> <font color=Cyan>}</font> <font color=Cyan>)</font>
<a name="line-369"></a> <font color=Cyan>,</font> <font color=Cyan>(</font><font color=Magenta>"Right"</font><font color=Cyan>,</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> fmap Right <font color=Cyan>$</font> parsePrec <font color=Magenta>10</font> <font color=Cyan>}</font> <font color=Cyan>)</font>
<a name="line-370"></a> <font color=Red>]</font>
<a name="line-371"></a>
<a name="line-372"></a><font color=Green><u>instance</u></font> Parse a <font color=Red>=></font> Parse <font color=Red>[</font>a<font color=Red>]</font> <font color=Green><u>where</u></font>
<a name="line-373"></a> parse <font color=Red>=</font> parseList
<a name="line-374"></a>
<a name="line-375"></a><font color=Blue>------------------------------------------------------------------------</font>
</pre>
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