factor/library/syntax/parse-syntax.factor

138 lines
3.3 KiB
Factor

! Copyright (C) 2004, 2005 Slava Pestov.
! See http://factor.sf.net/license.txt for BSD license.
! Bootstrapping trick; see doc/bootstrap.txt.
IN: !syntax
USING: alien errors generic hashtables kernel lists math
namespaces parser sequences strings syntax unparse vectors
words ;
: parsing ( -- )
#! Mark the most recently defined word to execute at parse
#! time, rather than run time. The word can use 'scan' to
#! read ahead in the input stream.
word t "parsing" set-word-prop ; parsing
: inline ( -- )
#! Mark the last word to be inlined.
word t "inline" set-word-prop ; parsing
: stateless ( -- )
#! Mark the last word to be evaluated at compile time if
#! all inputs are literals.
word t "stateless" set-word-prop ; parsing
! The variable "in-definition" is set inside a : ... ;.
! ( and #! then add "stack-effect" and "documentation"
! properties to the current word if it is set.
! Booleans
! The canonical t is a heap-allocated dummy object.
BUILTIN: t 7 t? ;
: t t swons ; parsing
! In the runtime, the canonical f is represented as a null
! pointer with tag 3. So
! f address . ==> 3
BUILTIN: f 9 not ;
: f f swons ; parsing
! Lists
: [ f ; parsing
: ] reverse swons ; parsing
! Conses (whose cdr might not be a list)
: [[ f ; parsing
: ]] 2unlist swons swons ; parsing
! Vectors
: { f ; parsing
: } reverse >vector swons ; parsing
! Hashtables
: {{ f ; parsing
: }} alist>hash swons ; parsing
! Tuples.
: << f ; parsing
: >> reverse literal-tuple swons ; parsing
! Do not execute parsing word
: POSTPONE: ( -- ) scan-word swons ; parsing
! Word definitions
: :
#! Begin a word definition. Word name follows.
CREATE [ define-compound ] [ ] "in-definition" on ; parsing
: ;
#! End a word definition.
"in-definition" off reverse swap call ; parsing
! Symbols
: SYMBOL:
#! A symbol is a word that pushes itself when executed.
CREATE define-symbol ; parsing
: \
#! Parsed as a piece of code that pushes a word on the stack
#! \ foo ==> [ foo ] car
scan-word literalize swons ; parsing
! Long wrapper syntax. Only used in the rare case that another
! wrapper is being wrapped.
: W[ [ ] ; parsing
: ]W first <wrapper> swons ; parsing
! Vocabularies
: PRIMITIVE:
#! This is just for show. All flash no substance.
"You cannot define primitives in Factor" throw ; parsing
: DEFER:
#! Create a word with no definition. Used for mutually
#! recursive words.
CREATE drop ; parsing
: FORGET:
#! Followed by a word name. The word is removed from its
#! vocabulary. Note that specifying an undefined word is a
#! no-op.
scan "use" get search [ forget ] when* ; parsing
: USE:
#! Add vocabulary to search path.
scan use+ ; parsing
: USING:
#! A list of vocabularies terminated with ;
string-mode on
[ string-mode off [ use+ ] each ]
f ; parsing
: IN:
#! Set vocabulary for new definitions.
scan dup use+ "in" set ; parsing
! Char literal
: CHAR: ( -- ) 0 scan next-char drop swons ; parsing
! String literal
: " parse-string swons ; parsing
: SBUF" skip-blank parse-string >sbuf swons ; parsing
! Comments
: (
#! Stack comment.
CHAR: ) until parsed-stack-effect ; parsing
: !
#! EOL comment.
until-eol drop ; parsing
: #!
#! Documentation comment.
until-eol parsed-documentation ; parsing