polyparse-1.1: docs/haddock/src/Text/ParserCombinators/Poly/NoLeak/State.html
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<pre><a name="(line1)"></a><font color=Green><u>module</u></font> Text<font color=Cyan>.</font>ParserCombinators<font color=Cyan>.</font>Poly<font color=Cyan>.</font>NoLeak<font color=Cyan>.</font>State
<a name="(line2)"></a> <font color=Cyan>(</font> <font color=Blue>-- * The Parser datatype</font>
<a name="(line3)"></a> Parser<font color=Cyan>(</font>P<font color=Cyan>)</font> <font color=Blue>-- datatype, instance of: Functor, Monad, PolyParse</font>
<a name="(line4)"></a> <font color=Cyan>,</font> runParser <font color=Blue>-- :: Parser s t a -> s -> [t] -> (Either String a, s, [t])</font>
<a name="(line5)"></a> <font color=Blue>-- ** basic parsers</font>
<a name="(line6)"></a> <font color=Cyan>,</font> next <font color=Blue>-- :: Parser s t t</font>
<a name="(line7)"></a> <font color=Cyan>,</font> satisfy <font color=Blue>-- :: (t->Bool) -> Parser s t t</font>
<a name="(line8)"></a> <font color=Blue>-- ** State-handling</font>
<a name="(line9)"></a> <font color=Cyan>,</font> stUpdate <font color=Blue>-- :: (s->s) -> Parser s t ()</font>
<a name="(line10)"></a> <font color=Cyan>,</font> stQuery <font color=Blue>-- :: (s->a) -> Parser s t a</font>
<a name="(line11)"></a> <font color=Cyan>,</font> stGet <font color=Blue>-- :: Parser s t s</font>
<a name="(line12)"></a> <font color=Blue>-- ** re-parsing</font>
<a name="(line13)"></a> <font color=Cyan>,</font> reparse <font color=Blue>-- :: [t] -> Parser s t ()</font>
<a name="(line14)"></a> <font color=Blue>-- * Re-export all more general combinators</font>
<a name="(line15)"></a> <font color=Cyan>,</font> <font color=Green><u>module</u></font> Text<font color=Cyan>.</font>ParserCombinators<font color=Cyan>.</font>Poly<font color=Cyan>.</font>Base
<a name="(line16)"></a> <font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="(line17)"></a>
<a name="(line18)"></a>
<a name="(line19)"></a><font color=Green><u>import</u></font> Text<font color=Cyan>.</font>ParserCombinators<font color=Cyan>.</font>Poly<font color=Cyan>.</font>Base
<a name="(line20)"></a>
<a name="(line21)"></a><a name="Parser"></a><font color=Blue>-- | This @Parser@ datatype is a fairly generic parsing monad with error</font>
<a name="(line22)"></a><a name="Parser"></a><font color=Blue>-- reporting. It can be used for arbitrary token types, not just</font>
<a name="(line23)"></a><a name="Parser"></a><font color=Blue>-- String input. (If you require a running state, use module PolyState</font>
<a name="(line24)"></a><a name="Parser"></a><font color=Blue>-- instead)</font>
<a name="(line25)"></a><a name="Parser"></a><font color=Green><u>newtype</u></font> Parser s t a <font color=Red>=</font> P <font color=Cyan>(</font>s <font color=Red>-></font> <font color=Red>[</font>t<font color=Red>]</font> <font color=Red>-></font> Result <font color=Red>[</font>t<font color=Red>]</font> s a<font color=Cyan>)</font>
<a name="(line26)"></a>
<a name="(line27)"></a><a name="Result"></a><font color=Blue>-- A return type like Either, that distinguishes not only between</font>
<a name="(line28)"></a><a name="Result"></a><font color=Blue>-- right and wrong answers, but also has gradations of wrongness.</font>
<a name="(line29)"></a><a name="Result"></a><font color=Green><u>data</u></font> Result z s a <font color=Red>=</font> Success z s a
<a name="(line30)"></a> <font color=Red>|</font> Failure z s String
<a name="(line31)"></a> <font color=Red>|</font> Committed <font color=Cyan>(</font>Result z s a<font color=Cyan>)</font>
<a name="(line32)"></a>
<a name="(line33)"></a><font color=Green><u>instance</u></font> Functor <font color=Cyan>(</font>Result z s<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="(line34)"></a> fmap f <font color=Cyan>(</font>Success z s a<font color=Cyan>)</font> <font color=Red>=</font> Success z s <font color=Cyan>(</font>f a<font color=Cyan>)</font>
<a name="(line35)"></a> fmap f <font color=Cyan>(</font>Failure z s e<font color=Cyan>)</font> <font color=Red>=</font> Failure z s e
<a name="(line36)"></a> fmap f <font color=Cyan>(</font>Committed r<font color=Cyan>)</font> <font color=Red>=</font> Committed <font color=Cyan>(</font>fmap f r<font color=Cyan>)</font>
<a name="(line37)"></a>
<a name="(line38)"></a><a name="runParser"></a><font color=Blue>-- | Apply a parser to an input token sequence.</font>
<a name="(line39)"></a>runParser <font color=Red>::</font> Parser s t a <font color=Red>-></font> s <font color=Red>-></font> <font color=Red>[</font>t<font color=Red>]</font> <font color=Red>-></font> <font color=Cyan>(</font>Either String a<font color=Cyan>,</font> s<font color=Cyan>,</font> <font color=Red>[</font>t<font color=Red>]</font><font color=Cyan>)</font>
<a name="(line40)"></a>runParser <font color=Cyan>(</font>P p<font color=Cyan>)</font> <font color=Red>=</font> <font color=Red>\</font>s<font color=Red>-></font> resultToEither <font color=Cyan>.</font> p s
<a name="(line41)"></a> <font color=Green><u>where</u></font>
<a name="(line42)"></a> resultToEither <font color=Red>::</font> Result z s a <font color=Red>-></font> <font color=Cyan>(</font>Either String a<font color=Cyan>,</font> s<font color=Cyan>,</font> z<font color=Cyan>)</font>
<a name="(line43)"></a> resultToEither <font color=Cyan>(</font>Success z s a<font color=Cyan>)</font> <font color=Red>=</font> <font color=Cyan>(</font>Right a<font color=Cyan>,</font> s<font color=Cyan>,</font> z<font color=Cyan>)</font>
<a name="(line44)"></a> resultToEither <font color=Cyan>(</font>Failure z s e<font color=Cyan>)</font> <font color=Red>=</font> <font color=Cyan>(</font>Left e<font color=Cyan>,</font> s<font color=Cyan>,</font> z<font color=Cyan>)</font>
<a name="(line45)"></a> resultToEither <font color=Cyan>(</font>Committed r<font color=Cyan>)</font> <font color=Red>=</font> resultToEither r
<a name="(line46)"></a>
<a name="(line47)"></a><font color=Green><u>instance</u></font> Functor <font color=Cyan>(</font>Parser s t<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="(line48)"></a> fmap f <font color=Cyan>(</font>P p<font color=Cyan>)</font> <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s<font color=Red>-></font> fmap f <font color=Cyan>.</font> p s<font color=Cyan>)</font>
<a name="(line49)"></a>
<a name="(line50)"></a><font color=Green><u>instance</u></font> Monad <font color=Cyan>(</font>Parser s t<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="(line51)"></a> return x <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> Success ts s x<font color=Cyan>)</font>
<a name="(line52)"></a> fail e <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> Failure ts s e<font color=Cyan>)</font>
<a name="(line53)"></a> <font color=Cyan>(</font>P f<font color=Cyan>)</font> <font color=Cyan>>>=</font> g <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s<font color=Red>-></font> continue <font color=Cyan>.</font> f s<font color=Cyan>)</font>
<a name="(line54)"></a> <font color=Green><u>where</u></font>
<a name="(line55)"></a> continue <font color=Cyan>(</font>Success ts s x<font color=Cyan>)</font> <font color=Red>=</font> <font color=Green><u>let</u></font> <font color=Cyan>(</font>P g'<font color=Cyan>)</font> <font color=Red>=</font> g x <font color=Green><u>in</u></font> g' s ts
<a name="(line56)"></a> continue <font color=Cyan>(</font>Committed <font color=Cyan>(</font>Committed r<font color=Cyan>)</font><font color=Cyan>)</font> <font color=Red>=</font> continue <font color=Cyan>(</font>Committed r<font color=Cyan>)</font>
<a name="(line57)"></a> continue <font color=Cyan>(</font>Committed r<font color=Cyan>)</font> <font color=Red>=</font> Committed <font color=Cyan>(</font>continue r<font color=Cyan>)</font>
<a name="(line58)"></a> continue <font color=Cyan>(</font>Failure ts s e<font color=Cyan>)</font> <font color=Red>=</font> Failure ts s e
<a name="(line59)"></a>
<a name="(line60)"></a><font color=Green><u>instance</u></font> PolyParse <font color=Cyan>(</font>Parser s t<font color=Cyan>)</font> <font color=Green><u>where</u></font>
<a name="(line61)"></a> commit <font color=Cyan>(</font>P p<font color=Cyan>)</font> <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s<font color=Red>-></font> Committed <font color=Cyan>.</font> p s<font color=Cyan>)</font>
<a name="(line62)"></a> <font color=Cyan>(</font>P p<font color=Cyan>)</font> <font color=Cyan>`adjustErr`</font> f <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s<font color=Red>-></font> adjust <font color=Cyan>.</font> p s<font color=Cyan>)</font>
<a name="(line63)"></a> <font color=Green><u>where</u></font>
<a name="(line64)"></a> adjust <font color=Cyan>(</font>Failure z s e<font color=Cyan>)</font> <font color=Red>=</font> Failure z s <font color=Cyan>(</font>f e<font color=Cyan>)</font>
<a name="(line65)"></a> adjust <font color=Cyan>(</font>Committed r<font color=Cyan>)</font> <font color=Red>=</font> Committed <font color=Cyan>(</font>adjust r<font color=Cyan>)</font>
<a name="(line66)"></a> adjust good <font color=Red>=</font> good
<a name="(line67)"></a>
<a name="(line68)"></a> <font color=Cyan>(</font>P p<font color=Cyan>)</font> <font color=Cyan>`onFail`</font> <font color=Cyan>(</font>P q<font color=Cyan>)</font> <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> continue s ts <font color=Cyan>$</font> p s ts<font color=Cyan>)</font>
<a name="(line69)"></a> <font color=Green><u>where</u></font>
<a name="(line70)"></a> continue s ts <font color=Cyan>(</font>Failure <font color=Green><u>_</u></font> <font color=Green><u>_</u></font> <font color=Green><u>_</u></font><font color=Cyan>)</font> <font color=Red>=</font> q s ts
<a name="(line71)"></a> <font color=Blue>-- continue _ _ (Committed r) = r -- no, remain Committed</font>
<a name="(line72)"></a> continue <font color=Green><u>_</u></font> <font color=Green><u>_</u></font> r <font color=Red>=</font> r
<a name="(line73)"></a>
<a name="(line74)"></a> oneOf' <font color=Red>=</font> accum []
<a name="(line75)"></a> <font color=Green><u>where</u></font> accum errs [] <font color=Red>=</font>
<a name="(line76)"></a> fail <font color=Cyan>(</font><font color=Magenta>"failed to parse any of the possible choices:\n"</font>
<a name="(line77)"></a> <font color=Cyan>++</font>indent <font color=Magenta>2</font> <font color=Cyan>(</font>concatMap showErr <font color=Cyan>(</font>reverse errs<font color=Cyan>)</font><font color=Cyan>)</font><font color=Cyan>)</font>
<a name="(line78)"></a> accum errs <font color=Cyan>(</font><font color=Cyan>(</font>e<font color=Cyan>,</font>P p<font color=Cyan>)</font><font color=Red><b>:</b></font>ps<font color=Cyan>)</font> <font color=Red>=</font>
<a name="(line79)"></a> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> <font color=Green><u>case</u></font> p s ts <font color=Green><u>of</u></font>
<a name="(line80)"></a> Failure <font color=Green><u>_</u></font> <font color=Green><u>_</u></font> err <font color=Red>-></font>
<a name="(line81)"></a> <font color=Green><u>let</u></font> <font color=Cyan>(</font>P p<font color=Cyan>)</font> <font color=Red>=</font> accum <font color=Cyan>(</font><font color=Cyan>(</font>e<font color=Cyan>,</font>err<font color=Cyan>)</font><font color=Red><b>:</b></font>errs<font color=Cyan>)</font> ps
<a name="(line82)"></a> <font color=Green><u>in</u></font> p s ts
<a name="(line83)"></a> r<font color=Red>@</font><font color=Cyan>(</font>Success z <font color=Green><u>_</u></font> a<font color=Cyan>)</font> <font color=Red>-></font> r
<a name="(line84)"></a> r<font color=Red>@</font><font color=Cyan>(</font>Committed <font color=Green><u>_</u></font><font color=Cyan>)</font> <font color=Red>-></font> r <font color=Cyan>)</font>
<a name="(line85)"></a> showErr <font color=Cyan>(</font>name<font color=Cyan>,</font>err<font color=Cyan>)</font> <font color=Red>=</font> name<font color=Cyan>++</font><font color=Magenta>":\n"</font><font color=Cyan>++</font>indent <font color=Magenta>2</font> err
<a name="(line86)"></a>
<a name="(line87)"></a><a name="next"></a><font color=Blue>------------------------------------------------------------------------</font>
<a name="(line88)"></a>next <font color=Red>::</font> Parser s t t
<a name="(line89)"></a>next <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> <font color=Green><u>case</u></font> ts <font color=Green><u>of</u></font>
<a name="(line90)"></a> [] <font color=Red>-></font> Failure [] s <font color=Magenta>"Ran out of input (EOF)"</font>
<a name="(line91)"></a> <font color=Cyan>(</font>t<font color=Red><b>:</b></font>ts'<font color=Cyan>)</font> <font color=Red>-></font> Success ts' s t <font color=Cyan>)</font>
<a name="(line92)"></a>
<a name="(line93)"></a><a name="satisfy"></a>satisfy <font color=Red>::</font> <font color=Cyan>(</font>t<font color=Red>-></font>Bool<font color=Cyan>)</font> <font color=Red>-></font> Parser s t t
<a name="(line94)"></a>satisfy pred <font color=Red>=</font> <font color=Green><u>do</u></font> <font color=Cyan>{</font> x <font color=Red><-</font> next
<a name="(line95)"></a> <font color=Cyan>;</font> <font color=Green><u>if</u></font> pred x <font color=Green><u>then</u></font> return x <font color=Green><u>else</u></font> fail <font color=Magenta>"Parse.satisfy: failed"</font>
<a name="(line96)"></a> <font color=Cyan>}</font>
<a name="(line97)"></a><font color=Blue>------------------------------------------------------------------------</font>
<a name="(line98)"></a><font color=Blue>-- State handling</font>
<a name="(line99)"></a>
<a name="(line100)"></a><a name="stUpdate"></a><font color=Blue>-- | Update the internal state.</font>
<a name="(line101)"></a>stUpdate <font color=Red>::</font> <font color=Cyan>(</font>s<font color=Red>-></font>s<font color=Cyan>)</font> <font color=Red>-></font> Parser s t ()
<a name="(line102)"></a>stUpdate f <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> Success ts <font color=Cyan>(</font>f s<font color=Cyan>)</font> ()<font color=Cyan>)</font>
<a name="(line103)"></a>
<a name="(line104)"></a><a name="stQuery"></a><font color=Blue>-- | Query the internal state.</font>
<a name="(line105)"></a>stQuery <font color=Red>::</font> <font color=Cyan>(</font>s<font color=Red>-></font>a<font color=Cyan>)</font> <font color=Red>-></font> Parser s t a
<a name="(line106)"></a>stQuery f <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> Success ts s <font color=Cyan>(</font>f s<font color=Cyan>)</font><font color=Cyan>)</font>
<a name="(line107)"></a>
<a name="(line108)"></a><a name="stGet"></a><font color=Blue>-- | Deliver the entire internal state.</font>
<a name="(line109)"></a>stGet <font color=Red>::</font> Parser s t s
<a name="(line110)"></a>stGet <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s ts<font color=Red>-></font> Success ts s s<font color=Cyan>)</font>
<a name="(line111)"></a>
<a name="(line112)"></a>
<a name="(line113)"></a><a name="reparse"></a><font color=Blue>------------------------------------------------------------------------</font>
<a name="(line114)"></a><font color=Blue>-- | Push some tokens back onto the front of the input stream and reparse.</font>
<a name="(line115)"></a><font color=Blue>-- This is useful e.g. for recursively expanding macros. When the</font>
<a name="(line116)"></a><font color=Blue>-- user-parser recognises a macro use, it can lookup the macro</font>
<a name="(line117)"></a><font color=Blue>-- expansion from the parse state, lex it, and then stuff the</font>
<a name="(line118)"></a><font color=Blue>-- lexed expansion back down into the parser.</font>
<a name="(line119)"></a>reparse <font color=Red>::</font> <font color=Red>[</font>t<font color=Red>]</font> <font color=Red>-></font> Parser s t ()
<a name="(line120)"></a>reparse ts <font color=Red>=</font> P <font color=Cyan>(</font><font color=Red>\</font>s inp<font color=Red>-></font> Success <font color=Cyan>(</font>ts<font color=Cyan>++</font>inp<font color=Cyan>)</font> s ()<font color=Cyan>)</font>
<a name="(line121)"></a>
<a name="(line122)"></a><font color=Blue>------------------------------------------------------------------------</font>
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