factor/library/syntax/parse-syntax.factor

150 lines
3.6 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 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
: flushable ( -- )
#! Declare that a word may be removed if the value it
#! computes is unused.
word t "flushable" set-word-prop ; parsing
: foldable ( -- )
#! Declare a word as safe for compile-time evaluation.
#! Foldable implies flushable, since we can first fold to
#! a constant then flush the constant.
word
dup t "foldable" set-word-prop
t "flushable" 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
: t t swons ; parsing
: f f swons ; parsing
! Lists
: [ f ; parsing
: ] reverse swons ; parsing
! Conses (whose cdr might not be a list)
: [[ f ; parsing
: ]] 2unseq swons swons ; parsing
! Vectors
: { f ; parsing
: } reverse >vector swons ; parsing
! Hashtables
: {{ f ; parsing
: }} alist>hash swons ; parsing
! Do not execute parsing word
: POSTPONE: ( -- ) scan-word swons ; parsing
! Word definitions
: :
#! Begin a word definition. Word name follows.
CREATE dup reset-generic [ 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 dup reset-generic define-symbol ; parsing
: \
#! Word literals: \ foo
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 dup reset-generic 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
! Complex numbers
: #{ f ; parsing
: }# dup second swap first rect> swons ; parsing
! Reading integers in other bases
: (BASE) ( base -- )
#! Reads an integer in a specific base.
scan swap base> swons ;
: HEX: 16 (BASE) ; parsing
: DEC: 10 (BASE) ; parsing
: OCT: 8 (BASE) ; parsing
: BIN: 2 (BASE) ; parsing