add 1token and docs

extra/peg/parsers/parsers-docs.factor

@@ -1,9 +1,19 @@
-! Copyright (C) 2007 Chris Double.
+! Copyright (C) 2008 Chris Double, Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: help.markup help.syntax peg peg.parsers.private
 unicode.categories ;
 IN: peg.parsers
 
+HELP: 1token
+{ $values
+    { "ch" "a character" }
+    { "parser" "a parser" }
+} { $description
+    "Calls 1string on a character and returns a parser that matches that character."
+} { $examples
+    { $example "USING: peg peg.parsers prettyprint ;" "\"a\" CHAR: a 1token parse parse-result-ast ." "\"a\"" }
+} { $see-also 'string' } ;
+
 HELP: (list-of)
 { $values
     { "items" "a sequence" }

extra/peg/parsers/parsers.factor

@@ -21,6 +21,8 @@ M: just-parser compile ( parser -- quot )
 MEMO: just ( parser -- parser )
   just-parser construct-boa init-parser ;
 
+MEMO: 1token ( ch -- parser ) 1string token ;
+
 <PRIVATE
 MEMO: (list-of) ( items separator repeat1? -- parser )
   >r over 2seq r> [ repeat1 ] [ repeat0 ] if [ concat ] action 2seq