Sophie: ghc-0:6.10.4-1mdv2010.0 i586

ghc-6.10.4-1mdv2010.0.i586.rpm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<!--Rendered using the Haskell Html Library v0.2-->
<HTML
><HEAD
><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8"
><TITLE
>Distribution.Compat.ReadP</TITLE
><LINK HREF="haddock.css" REL="stylesheet" TYPE="text/css"
><SCRIPT SRC="haddock-util.js" TYPE="text/javascript"
></SCRIPT
><SCRIPT TYPE="text/javascript"
>window.onload = function () {setSynopsis("mini_Distribution-Compat-ReadP.html")};</SCRIPT
></HEAD
><BODY
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="topbar"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD
><IMG SRC="haskell_icon.gif" WIDTH="16" HEIGHT="16" ALT=" "
></TD
><TD CLASS="title"
>Cabal-1.6.0.3: A framework for packaging Haskell software</TD
><TD CLASS="topbut"
><A HREF="index.html"
>Contents</A
></TD
><TD CLASS="topbut"
><A HREF="doc-index.html"
>Index</A
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="modulebar"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD
><FONT SIZE="6"
>Distribution.Compat.ReadP</FONT
></TD
><TD ALIGN="right"
><TABLE CLASS="narrow" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="infohead"
>Portability</TD
><TD CLASS="infoval"
>portable</TD
></TR
><TR
><TD CLASS="infohead"
>Maintainer</TD
><TD CLASS="infoval"
>libraries@haskell.org</TD
></TR
></TABLE
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="section4"
><B
>Contents</B
></TD
></TR
><TR
><TD
><DL
><DT
><A HREF="#1"
>The <TT
><A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
></TT
> type
</A
></DT
><DT
><A HREF="#2"
>Primitive operations
</A
></DT
><DT
><A HREF="#3"
>Other operations
</A
></DT
><DT
><A HREF="#4"
>Running a parser
</A
></DT
><DT
><A HREF="#5"
>Properties
</A
></DT
></DL
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Description</TD
></TR
><TR
><TD CLASS="doc"
><P
>This is a library of parser combinators, originally written by Koen Claessen.
 It parses all alternatives in parallel, so it never keeps hold of
 the beginning of the input string, a common source of space leaks with
 other parsers.  The '(+++)' choice combinator is genuinely commutative;
 it makes no difference which branch is &quot;shorter&quot;.
</P
><P
>See also Koen's paper <EM
>Parallel Parsing Processes</EM
>
 (<A HREF="http://www.cs.chalmers.se/~koen/publications.html"
>http://www.cs.chalmers.se/~koen/publications.html</A
>).
</P
><P
>This version of ReadP has been locally hacked to make it H98, by
 Martin Sj&#xf6;gren <A HREF="mailto:msjogren@gmail.com"
>mailto:msjogren@gmail.com</A
>
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Synopsis</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>type</SPAN
> <A HREF="#t%3AReadP"
>ReadP</A
> r a = Parser r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Aget"
>get</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Alook"
>look</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3A%2B%2B%2B"
>(+++)</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3A%3C%2B%2B"
>(&lt;++)</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> a a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Agather"
>gather</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> (<A HREF="../base/Data-Char.html#t%3AString"
>String</A
> -&gt; P <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> r) a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (<A HREF="../base/Data-Char.html#t%3AString"
>String</A
>, a)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Apfail"
>pfail</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Asatisfy"
>satisfy</A
> ::  (<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="../ghc-prim/GHC-Bool.html#t%3ABool"
>Bool</A
>) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Achar"
>char</A
> ::  <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Astring"
>string</A
> ::  <A HREF="../base/Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Amunch"
>munch</A
> ::  (<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="../ghc-prim/GHC-Bool.html#t%3ABool"
>Bool</A
>) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Amunch1"
>munch1</A
> ::  (<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="../ghc-prim/GHC-Bool.html#t%3ABool"
>Bool</A
>) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AskipSpaces"
>skipSpaces</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Achoice"
>choice</A
> ::  [<A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a] -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Acount"
>count</A
> ::  <A HREF="../ghc-prim/GHC-Types.html#t%3AInt"
>Int</A
> -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Abetween"
>between</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r open -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r close -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Aoption"
>option</A
> ::  a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Aoptional"
>optional</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Amany"
>many</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Amany1"
>many1</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AskipMany"
>skipMany</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AskipMany1"
>skipMany1</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AsepBy"
>sepBy</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AsepBy1"
>sepBy1</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AendBy"
>endBy</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AendBy1"
>endBy1</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Achainr"
>chainr</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Achainl"
>chainl</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Achainl1"
>chainl1</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Achainr1"
>chainr1</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AmanyTill"
>manyTill</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> [a] end -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="../base/Text-ParserCombinators-ReadP.html#t%3AReadS"
>ReadS</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AreadP_to_S"
>readP_to_S</A
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> a a -&gt; <A HREF="../base/Text-ParserCombinators-ReadP.html#t%3AReadS"
>ReadS</A
> a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AreadS_to_P"
>readS_to_P</A
> ::  <A HREF="../base/Text-ParserCombinators-ReadP.html#t%3AReadS"
>ReadS</A
> a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="1"
><A NAME="1"
>The <TT
><A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
></TT
> type
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>type</SPAN
> <A NAME="t:ReadP"
><A NAME="t%3AReadP"
></A
></A
><B
>ReadP</B
> r a = Parser r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> a</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="2"
><A NAME="2"
>Primitive operations
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:get"
><A NAME="v%3Aget"
></A
></A
><B
>get</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
></TD
></TR
><TR
><TD CLASS="doc"
>Consumes and returns the next character.
   Fails if there is no input left.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:look"
><A NAME="v%3Alook"
></A
></A
><B
>look</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="doc"
>Look-ahead: returns the part of the input that is left, without
   consuming it.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:+++"
><A NAME="v%3A%2B%2B%2B"
></A
></A
><B
>(+++)</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Symmetric choice.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:<++"
><A NAME="v%3A%3C%2B%2B"
></A
></A
><B
>(&lt;++)</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> a a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Local, exclusive, left-biased choice: If left parser
   locally produces any result at all, then right parser is
   not used.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:gather"
><A NAME="v%3Agather"
></A
></A
><B
>gather</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> (<A HREF="../base/Data-Char.html#t%3AString"
>String</A
> -&gt; P <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> r) a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (<A HREF="../base/Data-Char.html#t%3AString"
>String</A
>, a)</TD
></TR
><TR
><TD CLASS="doc"
>Transforms a parser into one that does the same, but
   in addition returns the exact characters read.
   IMPORTANT NOTE: <TT
><A HREF="Distribution-Compat-ReadP.html#v%3Agather"
>gather</A
></TT
> gives a runtime error if its first argument
   is built using any occurrences of readS_to_P.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="3"
><A NAME="3"
>Other operations
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:pfail"
><A NAME="v%3Apfail"
></A
></A
><B
>pfail</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Always fails.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:satisfy"
><A NAME="v%3Asatisfy"
></A
></A
><B
>satisfy</B
> ::  (<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="../ghc-prim/GHC-Bool.html#t%3ABool"
>Bool</A
>) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
></TD
></TR
><TR
><TD CLASS="doc"
>Consumes and returns the next character, if it satisfies the
   specified predicate.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:char"
><A NAME="v%3Achar"
></A
></A
><B
>char</B
> ::  <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
></TD
></TR
><TR
><TD CLASS="doc"
>Parses and returns the specified character.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:string"
><A NAME="v%3Astring"
></A
></A
><B
>string</B
> ::  <A HREF="../base/Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="doc"
>Parses and returns the specified string.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:munch"
><A NAME="v%3Amunch"
></A
></A
><B
>munch</B
> ::  (<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="../ghc-prim/GHC-Bool.html#t%3ABool"
>Bool</A
>) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="doc"
>Parses the first zero or more characters satisfying the predicate.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:munch1"
><A NAME="v%3Amunch1"
></A
></A
><B
>munch1</B
> ::  (<A HREF="../ghc-prim/GHC-Types.html#t%3AChar"
>Char</A
> -&gt; <A HREF="../ghc-prim/GHC-Bool.html#t%3ABool"
>Bool</A
>) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../base/Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="doc"
>Parses the first one or more characters satisfying the predicate.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:skipSpaces"
><A NAME="v%3AskipSpaces"
></A
></A
><B
>skipSpaces</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="doc"
>Skips all whitespace.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:choice"
><A NAME="v%3Achoice"
></A
></A
><B
>choice</B
> ::  [<A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a] -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Combines all parsers in the specified list.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:count"
><A NAME="v%3Acount"
></A
></A
><B
>count</B
> ::  <A HREF="../ghc-prim/GHC-Types.html#t%3AInt"
>Int</A
> -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
><TT
> count n p </TT
> parses <TT
>n</TT
> occurrences of <TT
>p</TT
> in sequence. A list of
   results is returned.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:between"
><A NAME="v%3Abetween"
></A
></A
><B
>between</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r open -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r close -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
><TT
> between open close p </TT
> parses <TT
>open</TT
>, followed by <TT
>p</TT
> and finally
   <TT
>close</TT
>. Only the value of <TT
>p</TT
> is returned.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:option"
><A NAME="v%3Aoption"
></A
></A
><B
>option</B
> ::  a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
><TT
>option x p</TT
> will either parse <TT
>p</TT
> or return <TT
>x</TT
> without consuming
   any input.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:optional"
><A NAME="v%3Aoptional"
></A
></A
><B
>optional</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="doc"
><TT
>optional p</TT
> optionally parses <TT
>p</TT
> and always returns <TT
>()</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:many"
><A NAME="v%3Amany"
></A
></A
><B
>many</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
>Parses zero or more occurrences of the given parser.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:many1"
><A NAME="v%3Amany1"
></A
></A
><B
>many1</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
>Parses one or more occurrences of the given parser.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:skipMany"
><A NAME="v%3AskipMany"
></A
></A
><B
>skipMany</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="doc"
>Like <TT
><A HREF="Distribution-Compat-ReadP.html#v%3Amany"
>many</A
></TT
>, but discards the result.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:skipMany1"
><A NAME="v%3AskipMany1"
></A
></A
><B
>skipMany1</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r <A HREF="../ghc-prim/GHC-Unit.html#t%3A%28%29"
>()</A
></TD
></TR
><TR
><TD CLASS="doc"
>Like <TT
><A HREF="Distribution-Compat-ReadP.html#v%3Amany1"
>many1</A
></TT
>, but discards the result.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:sepBy"
><A NAME="v%3AsepBy"
></A
></A
><B
>sepBy</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
><TT
>sepBy p sep</TT
> parses zero or more occurrences of <TT
>p</TT
>, separated by <TT
>sep</TT
>.
   Returns a list of values returned by <TT
>p</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:sepBy1"
><A NAME="v%3AsepBy1"
></A
></A
><B
>sepBy1</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
><TT
>sepBy1 p sep</TT
> parses one or more occurrences of <TT
>p</TT
>, separated by <TT
>sep</TT
>.
   Returns a list of values returned by <TT
>p</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:endBy"
><A NAME="v%3AendBy"
></A
></A
><B
>endBy</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
><TT
>endBy p sep</TT
> parses zero or more occurrences of <TT
>p</TT
>, separated and ended
   by <TT
>sep</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:endBy1"
><A NAME="v%3AendBy1"
></A
></A
><B
>endBy1</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r sep -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
><TT
>endBy p sep</TT
> parses one or more occurrences of <TT
>p</TT
>, separated and ended
   by <TT
>sep</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:chainr"
><A NAME="v%3Achainr"
></A
></A
><B
>chainr</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
><TT
>chainr p op x</TT
> parses zero or more occurrences of <TT
>p</TT
>, separated by <TT
>op</TT
>.
   Returns a value produced by a <EM
>right</EM
> associative application of all
   functions returned by <TT
>op</TT
>. If there are no occurrences of <TT
>p</TT
>, <TT
>x</TT
> is
   returned.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:chainl"
><A NAME="v%3Achainl"
></A
></A
><B
>chainl</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
><TT
>chainl p op x</TT
> parses zero or more occurrences of <TT
>p</TT
>, separated by <TT
>op</TT
>.
   Returns a value produced by a <EM
>left</EM
> associative application of all
   functions returned by <TT
>op</TT
>. If there are no occurrences of <TT
>p</TT
>, <TT
>x</TT
> is
   returned.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:chainl1"
><A NAME="v%3Achainl1"
></A
></A
><B
>chainl1</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Like <TT
><A HREF="Distribution-Compat-ReadP.html#v%3Achainl"
>chainl</A
></TT
>, but parses one or more occurrences of <TT
>p</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:chainr1"
><A NAME="v%3Achainr1"
></A
></A
><B
>chainr1</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r (a -&gt; a -&gt; a) -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Like <TT
><A HREF="Distribution-Compat-ReadP.html#v%3Achainr"
>chainr</A
></TT
>, but parses one or more occurrences of <TT
>p</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:manyTill"
><A NAME="v%3AmanyTill"
></A
></A
><B
>manyTill</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> [a] end -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r [a]</TD
></TR
><TR
><TD CLASS="doc"
><TT
>manyTill p end</TT
> parses zero or more occurrences of <TT
>p</TT
>, until <TT
>end</TT
>
   succeeds. Returns a list of values returned by <TT
>p</TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="4"
><A NAME="4"
>Running a parser
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="../base/Text-ParserCombinators-ReadP.html#t%3AReadS"
>ReadS</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:readP_to_S"
><A NAME="v%3AreadP_to_S"
></A
></A
><B
>readP_to_S</B
> ::  <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> a a -&gt; <A HREF="../base/Text-ParserCombinators-ReadP.html#t%3AReadS"
>ReadS</A
> a</TD
></TR
><TR
><TD CLASS="doc"
>Converts a parser into a Haskell ReadS-style function.
   This is the main way in which you can &quot;run&quot; a <TT
><A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
></TT
> parser:
   the expanded type is
 <TT
> readP_to_S :: ReadP a -&gt; String -&gt; [(a,String)] </TT
>
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:readS_to_P"
><A NAME="v%3AreadS_to_P"
></A
></A
><B
>readS_to_P</B
> ::  <A HREF="../base/Text-ParserCombinators-ReadP.html#t%3AReadS"
>ReadS</A
> a -&gt; <A HREF="Distribution-Compat-ReadP.html#t%3AReadP"
>ReadP</A
> r a</TD
></TR
><TR
><TD CLASS="doc"
>Converts a Haskell ReadS-style function into a parser.
   Warning: This introduces local backtracking in the resulting
   parser, and therefore a possible inefficiency.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="5"
><A NAME="5"
>Properties
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="doc"
><P
>The following are QuickCheck specifications of what the combinators do.
These can be seen as formal specifications of the behavior of the
combinators.
</P
><P
>We use bags to give semantics to the combinators.
</P
><PRE
>  type Bag a = [a]
</PRE
><P
>Equality on bags does not care about the order of elements.
</P
><PRE
>  (=~) :: Ord a =&gt; Bag a -&gt; Bag a -&gt; Bool
  xs =~ ys = sort xs == sort ys
</PRE
><P
>A special equality operator to avoid unresolved overloading
when testing the properties.
</P
><PRE
>  (=~.) :: Bag (Int,String) -&gt; Bag (Int,String) -&gt; Bool
  (=~.) = (=~)
</PRE
><P
>Here follow the properties:
</P
><PRE
>  prop_Get_Nil =
    readP_to_S get [] =~ []

  prop_Get_Cons c s =
    readP_to_S get (c:s) =~ [(c,s)]

  prop_Look s =
    readP_to_S look s =~ [(s,s)]

  prop_Fail s =
    readP_to_S pfail s =~. []

  prop_Return x s =
    readP_to_S (return x) s =~. [(x,s)]

  prop_Bind p k s =
    readP_to_S (p &gt;&gt;= k) s =~.
      [ ys''
      | (x,s') &lt;- readP_to_S p s
      , ys''   &lt;- readP_to_S (k (x::Int)) s'
      ]

  prop_Plus p q s =
    readP_to_S (p +++ q) s =~.
      (readP_to_S p s ++ readP_to_S q s)

  prop_LeftPlus p q s =
    readP_to_S (p &lt;++ q) s =~.
      (readP_to_S p s +&lt;+ readP_to_S q s)
   where
    [] +&lt;+ ys = ys
    xs +&lt;+ _  = xs

  prop_Gather s =
    forAll readPWithoutReadS $ \p -&gt;
      readP_to_S (gather p) s =~
	 [ ((pre,x::Int),s')
	 | (x,s') &lt;- readP_to_S p s
	 , let pre = take (length s - length s') s
	 ]

  prop_String_Yes this s =
    readP_to_S (string this) (this ++ s) =~
      [(this,s)]

  prop_String_Maybe this s =
    readP_to_S (string this) s =~
      [(this, drop (length this) s) | this `isPrefixOf` s]

  prop_Munch p s =
    readP_to_S (munch p) s =~
      [(takeWhile p s, dropWhile p s)]

  prop_Munch1 p s =
    readP_to_S (munch1 p) s =~
      [(res,s') | let (res,s') = (takeWhile p s, dropWhile p s), not (null res)]

  prop_Choice ps s =
    readP_to_S (choice ps) s =~.
      readP_to_S (foldr (+++) pfail ps) s

  prop_ReadS r s =
    readP_to_S (readS_to_P r) s =~. r s
</PRE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="botbar"
>Produced by <A HREF="http://www.haskell.org/haddock/"
>Haddock</A
> version 2.4.2</TD
></TR
></TABLE
></BODY
></HTML
>