-HELP: c-setter
-{ $values { "name" string } { "quot" { $quotation "( obj c-ptr n -- )" } } }
-{ $description "Outputs a quotation which writes values of this C type to a C structure." }
-{ $errors "Throws an error if the type does not exist." } ;
-
-HELP: <c-array>
-{ $values { "len" "a non-negative integer" } { "c-type" "a C type" } { "array" byte-array } }
-{ $description "Creates a byte array large enough to hold " { $snippet "n" } " values of a C type." }
-{ $notes "The appropriate specialized array vocabulary must be loaded; otherwise, an error will be thrown. The vocabulary can be loaded with the " { $link require-c-array } " word. See the " { $vocab-link "specialized-arrays" } " vocabulary for details on the underlying sequence type constructed." }
-{ $errors "Throws an error if the type does not exist, the necessary specialized array vocabulary is not loaded, or the requested size is negative." } ;
-
-HELP: <c-object>
-{ $values { "type" "a C type" } { "array" byte-array } }
-{ $description "Creates a byte array suitable for holding a value with the given C type." }
-{ $errors "Throws an " { $link no-c-type } " error if the type does not exist." } ;
-
-{ <c-object> malloc-object } related-words
-
-HELP: memory>byte-array
-{ $values { "alien" c-ptr } { "len" "a non-negative integer" } { "byte-array" byte-array } }
-{ $description "Reads " { $snippet "len" } " bytes starting from " { $snippet "base" } " and stores them in a new byte array." } ;
-
-HELP: byte-array>memory
-{ $values { "byte-array" byte-array } { "base" c-ptr } }
-{ $description "Writes a byte array to memory starting from the " { $snippet "base" } " address." }
-{ $warning "This word is unsafe. Improper use can corrupt memory." } ;
-
-HELP: malloc-array
-{ $values { "n" "a non-negative integer" } { "type" "a C type" } { "alien" alien } }
-{ $description "Allocates an unmanaged memory block large enough to hold " { $snippet "n" } " values of a C type, then wraps the memory in a sequence object using " { $link <c-direct-array> } "." }
-{ $notes "The appropriate specialized array vocabulary must be loaded; otherwise, an error will be thrown. The vocabulary can be loaded with the " { $link require-c-array } " word. See the " { $vocab-link "specialized-arrays" } " vocabulary for details on the underlying sequence type constructed." }
-{ $warning "Don't forget to deallocate the memory with a call to " { $link free } "." }
-{ $errors "Throws an error if the type does not exist, if the requested size is negative, if a direct specialized array class appropriate to the type is not loaded, or if memory allocation fails." } ;
-
-HELP: malloc-object
-{ $values { "type" "a C type" } { "alien" alien } }
-{ $description "Allocates an unmanaged memory block large enough to hold a value of a C type." }
-{ $warning "Don't forget to deallocate the memory with a call to " { $link free } "." }
-{ $errors "Throws an error if the type does not exist or if memory allocation fails." } ;
-
-HELP: malloc-byte-array
-{ $values { "byte-array" byte-array } { "alien" alien } }
-{ $description "Allocates an unmanaged memory block of the same size as the byte array, and copies the contents of the byte array there." }
-{ $warning "Don't forget to deallocate the memory with a call to " { $link free } "." }
-{ $errors "Throws an error if memory allocation fails." } ;
-
-{ <c-array> <c-direct-array> malloc-array } related-words
-
-HELP: box-parameter
-{ $values { "n" integer } { "ctype" string } }
-{ $description "Generates code for converting a C value stored at offset " { $snippet "n" } " from the top of the stack into a Factor object to be pushed on the data stack." }
-{ $notes "This is an internal word used by the compiler when compiling callbacks." } ;
-
-HELP: box-return
-{ $values { "ctype" string } }
-{ $description "Generates code for converting a C value stored in return registers into a Factor object to be pushed on the data stack." }
-{ $notes "This is an internal word used by the compiler when compiling alien calls." } ;
-
-HELP: unbox-return
-{ $values { "ctype" string } }
-{ $description "Generates code for converting a Factor value on the data stack into a C value to be stored in the return registers." }
-{ $notes "This is an internal word used by the compiler when compiling callbacks." } ;
-
-HELP: define-deref
-{ $values { "name" "a word name" } }
-{ $description "Defines a word " { $snippet "*name" } " with stack effect " { $snippet "( c-ptr -- value )" } " for reading a value with C type " { $snippet "name" } " stored at an alien pointer." }
-{ $notes "This is an internal word called when defining C types, there is no need to call it on your own." } ;
-
-HELP: define-out
-{ $values { "name" "a word name" } }
-{ $description "Defines a word " { $snippet "<" { $emphasis "name" } ">" } " with stack effect " { $snippet "( value -- array )" } ". This word allocates a byte array large enough to hold a value with C type " { $snippet "name" } ", and writes the value at the top of the stack to the array." }
-{ $notes "This is an internal word called when defining C types, there is no need to call it on your own." } ;
-
-{ string>alien alien>string malloc-string } related-words
-
-HELP: malloc-string
-{ $values { "string" string } { "encoding" "an encoding descriptor" } { "alien" c-ptr } }
-{ $description "Encodes a string together with a trailing null code point using the given encoding, and stores the resulting bytes in a freshly-allocated unmanaged memory block." }
-{ $warning "Don't forget to deallocate the memory with a call to " { $link free } "." }
-{ $errors "Throws an error if one of the following conditions occurs:"
- { $list
- "the string contains null code points"
- "the string contains characters not representable using the encoding specified"
- "memory allocation fails"
- }
-} ;
-
-HELP: require-c-array
-{ $values { "c-type" "a C type" } }
-{ $description "Generates a specialized array of " { $snippet "c-type" } " using the " { $link <c-array> } " or " { $link <c-direct-array> } " vocabularies." }
-{ $notes "This word must be called inside a compilation unit. See the " { $vocab-link "specialized-arrays" } " vocabulary for details on the underlying sequence types loaded." } ;
-
-HELP: <c-direct-array>
-{ $values { "alien" c-ptr } { "len" integer } { "c-type" "a C type" } { "array" "a specialized direct array" } }
-{ $description "Constructs a new specialized array of length " { $snippet "len" } " and element type " { $snippet "c-type" } " over the range of memory referenced by " { $snippet "alien" } "." }
-{ $notes "The appropriate specialized array vocabulary must be loaded; otherwise, an error will be thrown. The vocabulary can be loaded with the " { $link require-c-array } " word. See the " { $vocab-link "specialized-arrays" } " vocabulary for details on the underlying sequence type constructed." } ;
-
-ARTICLE: "c-strings" "C strings"
-"C string types are arrays with shape " { $snippet "{ \"char*\" encoding }" } ", where " { $snippet "encoding" } " is an encoding descriptor. The type " { $snippet "\"char*\"" } " is an alias for " { $snippet "{ \"char*\" utf8 }" } ". See " { $link "encodings-descriptors" } " for information about encoding descriptors."
-$nl
-"Passing a Factor string to a C function expecting a C string allocates a " { $link byte-array } " in the Factor heap; the string is then converted to the requested format and a raw pointer is passed to the function."
-$nl
-"If the conversion fails, for example if the string contains null bytes or characters with values higher than 255, a " { $link c-string-error. } " is thrown."
-$nl
-"Care must be taken if the C function expects a " { $snippet "char*" } " with a length in bytes, rather than a null-terminated " { $snippet "char*" } "; passing the result of calling " { $link length } " on the string object will not suffice. This is because a Factor string of " { $emphasis "n" } " characters will not necessarily encode to " { $emphasis "n" } " bytes. The correct idiom for C functions which take a string with a length is to first encode the string using " { $link encode } ", and then pass the resulting byte array together with the length of this byte array."
-$nl
-"Sometimes a C function has a parameter type of " { $snippet "void*" } ", and various data types, among them strings, can be passed in. In this case, strings are not automatically converted to aliens, and instead you must call one of these words:"
-{ $subsection string>alien }
-{ $subsection malloc-string }
-"The first allocates " { $link byte-array } "s, and the latter allocates manually-managed memory which is not moved by the garbage collector and has to be explicitly freed by calling " { $link free } ". See " { $link "byte-arrays-gc" } " for a discussion of the two approaches."
-$nl
-"A word to read strings from arbitrary addresses:"
-{ $subsection alien>string }
-"For example, if a C function returns a " { $snippet "char*" } " but stipulates that the caller must deallocate the memory afterward, you must define the function as returning " { $snippet "void*" } ", and call one of the above words before passing the pointer to " { $link free } "." ;
+HELP: char
+{ $description "This C type represents a one-byte signed integer type. Input values will be converted to " { $link math:integer } "s and truncated to eight bits; output values will be returned as " { $link math:fixnum } "s." } ;
+HELP: uchar
+{ $description "This C type represents a one-byte unsigned integer type. Input values will be converted to " { $link math:integer } "s and truncated to eight bits; output values will be returned as " { $link math:fixnum } "s." } ;
+HELP: short
+{ $description "This C type represents a two-byte signed integer type. Input values will be converted to " { $link math:integer } "s and truncated to sixteen bits; output values will be returned as " { $link math:fixnum } "s." } ;
+HELP: ushort
+{ $description "This C type represents a two-byte unsigned integer type. Input values will be converted to " { $link math:integer } "s and truncated to sixteen bits; output values will be returned as " { $link math:fixnum } "s." } ;
+HELP: int
+{ $description "This C type represents a four-byte signed integer type. Input values will be converted to " { $link math:integer } "s and truncated to 32 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: uint
+{ $description "This C type represents a four-byte unsigned integer type. Input values will be converted to " { $link math:integer } "s and truncated to 32 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: long
+{ $description "This C type represents a four- or eight-byte signed integer type. On Windows and on 32-bit Unix platforms, it will be four bytes. On 64-bit Unix platforms, it will be eight bytes. Input values will be converted to " { $link math:integer } "s and truncated to 32 or 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: intptr_t
+{ $description "This C type represents a signed integer type large enough to hold any pointer value; that is, on 32-bit platforms, it will be four bytes, and on 64-bit platforms, it will be eight bytes. Input values will be converted to " { $link math:integer } "s and truncated to 32 or 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: ulong
+{ $description "This C type represents a four- or eight-byte unsigned integer type. On Windows and on 32-bit Unix platforms, it will be four bytes. On 64-bit Unix platforms, it will be eight bytes. Input values will be converted to " { $link math:integer } "s and truncated to 32 or 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: uintptr_t
+{ $description "This C type represents an unsigned integer type large enough to hold any pointer value; that is, on 32-bit platforms, it will be four bytes, and on 64-bit platforms, it will be eight bytes. Input values will be converted to " { $link math:integer } "s and truncated to 32 or 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: ptrdiff_t
+{ $description "This C type represents a signed integer type large enough to hold the distance between two pointer values; that is, on 32-bit platforms, it will be four bytes, and on 64-bit platforms, it will be eight bytes. Input values will be converted to " { $link math:integer } "s and truncated to 32 or 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: size_t
+{ $description "This C type represents unsigned size values of the size expected by the platform's standard C library (usually four bytes on a 32-bit platform, and eight on a 64-bit platform). Input values will be converted to " { $link math:integer } "s and truncated to the appropriate size; output values will be returned as " { $link math:integer } "s." } ;
+HELP: longlong
+{ $description "This C type represents an eight-byte signed integer type. Input values will be converted to " { $link math:integer } "s and truncated to 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: ulonglong
+{ $description "This C type represents an eight-byte unsigned integer type. Input values will be converted to " { $link math:integer } "s and truncated to 64 bits; output values will be returned as " { $link math:integer } "s." } ;
+HELP: void
+{ $description "This symbol is not a valid C type, but it can be used as the return type for a " { $link POSTPONE: FUNCTION: } " or " { $link POSTPONE: CALLBACK: } " definition or for an " { $link alien-invoke } " or " { $link alien-callback } " call." } ;
+HELP: void*
+{ $description "This C type represents a generic pointer to C memory. See " { $link pointer } " for information on pointer C types." } ;
+HELP: c-string
+{ $description "This C type represents a pointer to a C string. See " { $link "c-strings" } " for details about using strings with the FFI." } ;
+HELP: float
+{ $description "This C type represents a single-precision IEEE 754 floating-point type. Input values will be converted to Factor " { $link math:float } "s and demoted to single-precision; output values will be returned as Factor " { $link math:float } "s." } ;
+HELP: double
+{ $description "This C type represents a double-precision IEEE 754 floating-point type. Input values will be converted to Factor " { $link math:float } "s; output values will be returned as Factor " { $link math:float } "s." } ;
+
+HELP: pointer:
+{ $syntax "pointer: c-type" }
+{ $description "Constructs a " { $link pointer } " C type." } ;
+
+HELP: pointer
+{ $class-description "Represents a pointer C type. The " { $snippet "to" } " slot contains the C type being pointed to. Both " { $link byte-array } " and " { $link alien } " values can be provided as pointer function inputs, but see " { $link "byte-arrays-gc" } " for notes about passing byte arrays into C functions. Objects with methods on " { $link >c-ptr } ", such as structs and specialized arrays, may also be used as pointer inputs."
+$nl
+"Pointer output values are represented in Factor as " { $link alien } "s. If the pointed-to type is a struct, the alien will automatically be wrapped in a struct object if it is not null."
+$nl
+"In " { $link POSTPONE: TYPEDEF: } ", " { $link POSTPONE: FUNCTION: } ", " { $link POSTPONE: CALLBACK: } ", and " { $link POSTPONE: STRUCT: } " definitions, pointer types can be created by suffixing " { $snippet "*" } " to a C type name. Outside of FFI definitions, a pointer C type can be created using the " { $link POSTPONE: pointer: } " syntax word:"
+{ $unchecked-example "FUNCTION: int* foo ( char* bar )" }
+{ $unchecked-example ": foo ( bar -- int* )
+ pointer: int f \"foo\" { pointer: char } f alien-invoke ;" } } ;