2 USING: alien alien.c-types alien.parser classes.struct help.markup help.syntax see ;
5 { $syntax "DLL\" path\"" }
6 { $values { "path" "a pathname string" } }
7 { $description "Constructs a DLL handle at parse time." } ;
10 { $syntax "ALIEN: address" }
11 { $values { "address" "a non-negative hexadecimal integer" } }
12 { $description "Creates an alien object at parse time." }
13 { $notes "Alien objects are invalidated between image saves and loads, and hence source files should not contain alien literals; this word is for interactive use only. See " { $link "alien-expiry" } " for details." } ;
15 ARTICLE: "syntax-aliens" "Alien object literal syntax"
16 { $subsection POSTPONE: ALIEN: }
17 { $subsection POSTPONE: DLL" } ;
20 { $syntax "LIBRARY: name" }
21 { $values { "name" "a logical library name" } }
22 { $description "Sets the logical library for consequent " { $link POSTPONE: FUNCTION: } " definitions that follow." } ;
25 { $syntax "FUNCTION: return name ( parameters )" }
26 { $values { "return" "a C return type" } { "name" "a C function name" } { "parameters" "a comma-separated sequence of type/name pairs; " { $snippet "type1 arg1, type2 arg2, ..." } } }
27 { $description "Defines a new word " { $snippet "name" } " which calls a C library function with the same name, in the logical library given by the most recent " { $link POSTPONE: LIBRARY: } " declaration."
29 "The new word must be compiled before being executed." }
31 "For example, suppose the " { $snippet "foo" } " library exports the following function:"
33 "void the_answer(char* question, int value) {"
34 " printf(\"The answer to %s is %d.\n\",question,value);"
37 "You can define a word for invoking it:"
39 "LIBRARY: foo\nFUNCTION: void the_answer ( char* question, int value ) ;"
41 "\"the question\" 42 the_answer"
42 "The answer to the question is 42."
44 { $notes "Note that the parentheses and commas are only syntax sugar and can be omitted; they serve no purpose other than to make the declaration slightly easier to read:"
46 "FUNCTION: void glHint ( GLenum target, GLenum mode ) ;"
47 "FUNCTION: void glHint GLenum target GLenum mode ;"
51 { $syntax "TYPEDEF: old new" }
52 { $values { "old" "a C type" } { "new" "a C type" } }
53 { $description "Aliases the C type " { $snippet "old" } " under the name " { $snippet "new" } " if ." }
54 { $notes "This word differs from " { $link typedef } " in that it runs at parse time, to ensure correct ordering of operations when loading source files. Words defined in source files are compiled before top-level forms are run, so if a source file defines C binding words and uses " { $link typedef } ", the type alias won't be available at compile time." } ;
57 { $syntax "C-ENUM: words... ;" }
58 { $values { "words" "a sequence of word names" } }
59 { $description "Creates a sequence of word definitions in the current vocabulary. Each word pushes an integer according to its index in the enumeration definition. The first word pushes 0." }
60 { $notes "This word emulates a C-style " { $snippet "enum" } " in Factor. While this feature can be used for any purpose, using integer constants is discouraged unless it is for interfacing with C libraries. Factor code should use " { $link "words.symbol" } " or " { $link "singletons" } " instead." }
62 "Here is an example enumeration definition:"
63 { $code "C-ENUM: red green blue ;" }
64 "It is equivalent to the following series of definitions:"
65 { $code "CONSTANT: red 0" "CONSTANT: green 1" "CONSTANT: blue 2" }
69 { $syntax "C-TYPE: type" }
70 { $values { "type" "a new C type" } }
71 { $description "Defines a new, opaque C type. Since it is opaque, " { $snippet "type" } " will not be directly usable as a parameter or return type of a " { $link POSTPONE: FUNCTION: } " or as a slot of a " { $link POSTPONE: STRUCT: } ". However, it can be used as the type of a pointer (that is, as " { $snippet "type*" } ")." $nl
72 { $snippet "C-TYPE:" } " can also be used to forward-declare C types to enable circular dependencies. For example:"
73 { $code """C-TYPE: forward
74 STRUCT: backward { x forward* } ;
75 STRUCT: forward { x backward* } ; """ } }
76 { $notes "Primitive C types are also displayed using " { $snippet "C-TYPE:" } " syntax when they are displayed by " { $link see } "." } ;
79 { $syntax "CALLBACK: return type ( parameters ) ;" }
80 { $values { "return" "a C return type" } { "type" "a type name" } { "parameters" "a comma-separated sequence of type/name pairs; " { $snippet "type1 arg1, type2 arg2, ..." } } }
81 { $description "Defines a new function pointer C type word " { $snippet "type" } ". The newly defined word works both as a C type and as a wrapper for " { $link alien-callback } " for callbacks that accept the given return type and parameters. The ABI of the callback is decided from the ABI of the active " { $link POSTPONE: LIBRARY: } " declaration." }
84 "CALLBACK: bool FakeCallback ( int message, void* payload ) ;"
85 ": MyFakeCallback ( -- alien )"
86 " [| message payload |"
87 " \"message #\" write"
88 " message number>string write"
89 " \" received\" write nl"
96 { $syntax "&: symbol" }
97 { $values { "symbol" "A C library symbol name" } }
98 { $description "Pushes the address of a symbol named " { $snippet "symbol" } " from the current library, set with " { $link POSTPONE: LIBRARY: } "." } ;
101 { $values { "old" "a string" } { "new" "a string" } }
102 { $description "Aliases the C type " { $snippet "old" } " under the name " { $snippet "new" } "." }
103 { $notes "Using this word in the same source file which defines C bindings can cause problems, because words are compiled before top-level forms are run. Use the " { $link POSTPONE: TYPEDEF: } " word instead." } ;
105 { POSTPONE: TYPEDEF: typedef } related-words
108 { $values { "c-type" "a C type name" } { "?" "a boolean" } }
109 { $description "Tests if a C type is a structure defined by " { $link POSTPONE: STRUCT: } "." } ;
111 HELP: define-function
112 { $values { "return" "a C return type" } { "library" "a logical library name" } { "function" "a C function name" } { "parameters" "a sequence of C parameter types" } }
113 { $description "Defines a word named " { $snippet "function" } " in the current vocabulary (see " { $link "vocabularies" } "). The word calls " { $link alien-invoke } " with the specified parameters." }
114 { $notes "This word is used to implement the " { $link POSTPONE: FUNCTION: } " parsing word." } ;