X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;f=doc%2Fref.sgml;h=39ae02ebaf9a920fceb1b76cef1a1671bd0f70fb;hb=005eb1c1210634a27fbc973d84004b5622456fc5;hp=607edfced873810076050e650872e0270ec179d5;hpb=d542c08a7adad816d6378fd6c80f62547033b866;p=uffi.git diff --git a/doc/ref.sgml b/doc/ref.sgml index 607edfc..39ae02e 100644 --- a/doc/ref.sgml +++ b/doc/ref.sgml @@ -96,8 +96,12 @@ dereferenced :char pointer returns an character. pointer returns an character. - :byte - Unsigned 8-bits. A + :byte - Signed 8-bits. A dereferenced :byte pointer returns an integer. + + + :unsigned-byte - Unsigned 8-bits. A +dereferenced :unsigned-byte pointer returns an integer. :short - Signed 16-bits. @@ -884,8 +888,8 @@ can be freed. size - An optional size parameter. If specified, allocates and returns an -array of type that is size members long. + An optional size parameter that is evaluated. If specified, allocates and returns an +array of type that is size members long. This parameter is evaluated. @@ -1046,6 +1050,61 @@ much better with static allocation. + + + size-of-foreign-type + Returns the number of data bytes used by a foreign object type. + + Macro + + + Syntax + + size-of-foreign-type ftype + + + + Arguments and Values + + + ftype + + A foreign type specifier. This parameter is evaluated. + + + + + + + Description + + Returns the number of data bytes used by a foreign object type. This does not include any Lisp storage overhead. + + + + Examples + + +(size-of-foreign-object :unsigned-byte) +=> 1 +(size-of-foreign-object 'my-100-byte-vector-type) +=> 100 + + + + + Side Effects + None. + + Affected by + None. + + + Exceptional Situations + None. + + + pointer-address @@ -1436,12 +1495,23 @@ if a cstring returned by a function is &null;. Overview - &uffi; has functions to two types of C-compatible + + &uffi; has functions to two types of +C-compatible strings, cstring and foreign strings. -cstrings are used as parameters to and from functions. An implementation, such as CMUCL, -may not convert these to a foreign type for efficiency sake. Thus, it is not -possible to "allocate" a cstring. In contrast, foreign strings -always need to have memory for them. + +cstrings are used as parameters to and from functions. An +implementation, such as CMUCL and Lispworks, a cstring may not be a +foreign type but rather the Lisp string itself while on other +platforms a cstring is a newly allocated foreign vector for storing +characters. Thus, it is not possible to portably +allocate a cstring. + + +In contrast, foreign strings +are always a foreign vector of characters which have a memory +allocated to hold them. Because of this, if you need to allocate memory to +hold the return value of a string, use a foreign string and not a cstring. @@ -1543,7 +1613,7 @@ that returns a cstring. Side Effects - None. + On some implementations, this function allocates memory. Affected by @@ -1645,7 +1715,7 @@ that returns a cstring. Description - Binds a lexical variable to a newly allocated cstring. Automatically frees cstring. + Binds a symbol to a cstring created from conversion of a string. Automatically frees the cstring.