steve
/
factor
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Some help for pegs

release
Chris Double 2007-11-27 12:22:33 +13:00
parent 6476eb765e
commit 99b39e0351
3 changed files with 141 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

108
extra/peg/peg-docs.factor
View File

@ -2,10 +2,112 @@
! See http://factorcode.org/license.txt for BSD license.
USING: help.markup help.syntax peg ;
HELP: parse
{ $values
{ "string" "a string" }
{ "parse" "a parser" }
{ "result" "a <parse-result> or f" }
}
{ $description
"Given the input string, parse it using the given parser. The result is a <parse-result> object if "
"the parse was successful, otherwise it is f." } ;
HELP: token
{ $values
{ "string" "a string" } }
{ "string" "a string" }
{ "parser" "a parser" }
}
{ $description
"A parser generator that returns a parser that matches the given string." }
{ $example "\"begin foo end\" \"begin\" token parse" "result-here" } ;
"Returns a parser that matches the given string." } ;
HELP: range
{ $values
{ "min" "a character" }
{ "max" "a character" }
{ "parser" "a parser" }
}
{ $description
"Returns a parser that matches a single character that lies within the range of characters given, inclusive." }
{ $example ": digit ( -- parser ) CHAR: 0 CHAR: 9 range ;" } ;
HELP: seq
{ $values
{ "seq" "a sequence of parsers" }
{ "parser" "a parser" }
}
{ $description
"Returns a parser that calls all parsers in the given sequence, in order. The parser succeeds if "
"all the parsers succeed, otherwise it fails. The AST produced is a sequence of the AST produced by "
"the individual parsers." } ;
HELP: choice
{ $values
{ "seq" "a sequence of parsers" }
{ "parser" "a parser" }
}
{ $description
"Returns a parser that will try all the parsers in the sequence, in order, until one succeeds. "
"The resulting AST is that produced by the successful parser." } ;
HELP: repeat0
{ $values
{ "p1" "a parser" }
{ "p2" "a parser" }
}
{ $description
"Returns a parser that parses 0 or more instances of the 'p1' parser. The AST produced is "
"an array of the AST produced by the 'p1' parser. An empty array indicates 0 instances were "
"parsed." } ;
HELP: repeat1
{ $values
{ "p1" "a parser" }
{ "p2" "a parser" }
}
{ $description
"Returns a parser that parses 1 or more instances of the 'p1' parser. The AST produced is "
"an array of the AST produced by the 'p1' parser." } ;
HELP: optional
{ $values
{ "p1" "a parser" }
{ "p2" "a parser" }
}
{ $description
"Returns a parser that parses 0 or 1 instances of the 'p1' parser. The AST produced is "
"'f' if 0 instances are parsed the AST produced is 'f', otherwise it is the AST produced by 'p1'." } ;
HELP: ensure
{ $values
{ "p1" "a parser" }
{ "p2" "a parser" }
}
{ $description
"Returns a parser that succeeds if the 'p1' parser succeeds but does not add anything to the "
"AST and does not move the location in the input string. This can be used for lookahead and "
"disambiguation, along with the " { $link ensure-not } " word." }
{ $example "\"0\" token ensure octal-parser" } ;
HELP: ensure-not
{ $values
{ "p1" "a parser" }
{ "p2" "a parser" }
}
{ $description
"Returns a parser that succeeds if the 'p1' parser fails but does not add anything to the "
"AST and does not move the location in the input string. This can be used for lookahead and "
"disambiguation, along with the " { $link ensure } " word." }
{ $example "\"+\" token \"=\" token ensure-not \"+=\" token 3array seq" } ;
HELP: action
{ $values
{ "p1" "a parser" }
{ "quot" "a quotation with stack effect ( ast -- ast )" }
}
{ $description
"Returns a parser that calls the 'p1' parser and applies the quotation to the AST resulting "
"from that parse. The result of the quotation is then used as the final AST. This can be used "
"for manipulating the parse tree to produce a AST better suited for the task at hand rather than "
"the default AST." }
{ $example "CHAR: 0 CHAR: 9 range [ to-digit ] action" } ;

2
extra/peg/peg-tests.factor
View File

@ -1,7 +1,7 @@
! Copyright (C) 2007 Chris Double.
! See http://factorcode.org/license.txt for BSD license.
!
USING: kernel tools.test strings namespaces arrays sequences peg ;
USING: kernel tools.test strings namespaces arrays sequences peg peg.private ;
IN: temporary
{ 0 1 2 } [

66
extra/peg/peg.factor
View File

@ -3,10 +3,14 @@
USING: kernel sequences strings namespaces math assocs shuffle vectors combinators.lib ;
IN: peg
SYMBOL: ignore
TUPLE: parse-result remaining ast ;
GENERIC: parse ( state parser -- result )
<PRIVATE
SYMBOL: ignore
: <parse-result> ( remaining ast -- parse-result )
parse-result construct-boa ;
@ -20,8 +24,6 @@ TUPLE: parser id ;
: init-parser ( parser -- parser )
get-next-id parser construct-boa over set-delegate ;
GENERIC: parse ( state parser -- result )
TUPLE: token-parser symbol ;
M: token-parser parse ( state parser -- result )
@ -31,9 +33,6 @@ M: token-parser parse ( state parser -- result )
2drop f
] if ;
: token ( string -- parser )
token-parser construct-boa init-parser ;
TUPLE: range-parser min max ;
M: range-parser parse ( state parser -- result )
@ -48,9 +47,6 @@ M: range-parser parse ( state parser -- result )
] if
] if ;
: range ( min max -- parser )
range-parser construct-boa init-parser ;
TUPLE: seq-parser parsers ;
: do-seq-parser ( result parser -- result )
@ -71,9 +67,6 @@ TUPLE: seq-parser parsers ;
M: seq-parser parse ( state parser -- result )
seq-parser-parsers [ V{ } clone <parse-result> ] dip (seq-parser) ;
: seq ( seq -- parser )
seq-parser construct-boa init-parser ;
TUPLE: choice-parser parsers ;
: (choice-parser) ( state parsers -- result )
@ -90,9 +83,6 @@ TUPLE: choice-parser parsers ;
M: choice-parser parse ( state parser -- result )
choice-parser-parsers (choice-parser) ;
: choice ( seq -- parser )
choice-parser construct-boa init-parser ;
TUPLE: repeat0-parser p1 ;
: (repeat-parser) ( parser result -- result )
@ -115,25 +105,16 @@ M: repeat0-parser parse ( state parser -- result )
drop V{ } clone <parse-result>
] if* ;
: repeat0 ( parser -- parser )
repeat0-parser construct-boa init-parser ;
TUPLE: repeat1-parser p1 ;
M: repeat1-parser parse ( state parser -- result )
repeat1-parser-p1 tuck parse dup [ clone-result (repeat-parser) ] [ nip ] if ;
: repeat1 ( parser -- parser )
repeat1-parser construct-boa init-parser ;
TUPLE: optional-parser p1 ;
M: optional-parser parse ( state parser -- result )
dupd optional-parser-p1 parse swap f <parse-result> or ;
: optional ( parser -- parser )
optional-parser construct-boa init-parser ;
TUPLE: ensure-parser p1 ;
M: ensure-parser parse ( state parser -- result )
@ -143,9 +124,6 @@ M: ensure-parser parse ( state parser -- result )
drop f
] if ;
: ensure ( parser -- parser )
ensure-parser construct-boa init-parser ;
TUPLE: ensure-not-parser p1 ;
M: ensure-not-parser parse ( state parser -- result )
@ -155,9 +133,6 @@ M: ensure-not-parser parse ( state parser -- result )
ignore <parse-result>
] if ;
: ensure-not ( parser -- parser )
ensure-not-parser construct-boa init-parser ;
TUPLE: action-parser p1 quot ;
M: action-parser parse ( state parser -- result )
@ -168,5 +143,34 @@ M: action-parser parse ( state parser -- result )
nip
] if ;
PRIVATE>
: token ( string -- parser )
token-parser construct-boa init-parser ;
: range ( min max -- parser )
range-parser construct-boa init-parser ;
: seq ( seq -- parser )
seq-parser construct-boa init-parser ;
: choice ( seq -- parser )
choice-parser construct-boa init-parser ;
: repeat0 ( parser -- parser )
repeat0-parser construct-boa init-parser ;
: repeat1 ( parser -- parser )
repeat1-parser construct-boa init-parser ;
: optional ( parser -- parser )
optional-parser construct-boa init-parser ;
: ensure ( parser -- parser )
ensure-parser construct-boa init-parser ;
: ensure-not ( parser -- parser )
ensure-not-parser construct-boa init-parser ;
: action ( parser quot -- parser )
action-parser construct-boa init-parser ;