X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pod%2Fperlxs.pod;h=15a7888697421f17e1b4e9fbac5d29a8d972f5ca;hb=70a63dff8306516881e1d108737939903cfadaef;hp=c9f7cc8549eb60336c9f819b8c875e520dd2033e;hpb=7207e29d564e32c8ec2cb43eabae72ff68c02442;p=p5sagit%2Fp5-mst-13.2.git diff --git a/pod/perlxs.pod b/pod/perlxs.pod index c9f7cc8..15a7888 100644 --- a/pod/perlxs.pod +++ b/pod/perlxs.pod @@ -310,6 +310,10 @@ keyword and must follow immediately after it when used. [ XS code in package RPC ] +The same package name can be used more than once, allowing for +non-contiguous code. This is useful if you have a stronger ordering +principle than package names. + Although this keyword is optional and in some cases provides redundant information it should always be used. This keyword will ensure that the XSUBs appear in the desired package. @@ -839,6 +843,31 @@ However, the generated Perl function is called in very C-ish style: my ($day, $month); day_month($day, time, $month); +=head2 The C Keyword + +If one of the input arguments to the C function is the length of a string +argument C, one can substitute the name of the length-argument by +C in the XSUB declaration. This argument must be omited when +the generated Perl function is called. E.g., + + void + dump_chars(char *s, short l) + { + short n = 0; + while (n < l) { + printf("s[%d] = \"\\%#03o\"\n", n, (int)s[n]); + n++; + } + } + + MODULE = x PACKAGE = x + + void dump_chars(char *s, short length(s)) + +should be called as C. + +This directive is supported with ANSI-type function declarations only. + =head2 Variable-length Parameter Lists XSUBs can have variable-length parameter lists by specifying an ellipsis @@ -1165,6 +1194,14 @@ prototypes. timep RETVAL +If the prototypes are enabled, you can disable it locally for a given +XSUB as in the following example: + + void + rpcb_gettime_noproto() + PROTOTYPE: DISABLE + ... + =head2 The ALIAS: Keyword The ALIAS: keyword allows an XSUB to have two or more unique Perl names @@ -1189,6 +1226,40 @@ C for this function. OUTPUT: timep +=head2 The OVERLOAD: Keyword + +Instead of writing an overloaded interface using pure Perl, you +can also use the OVERLOAD keyword to define additional Perl names +for your functions (like the ALIAS: keyword above). However, the +overloaded functions must be defined with three parameters (except +for the nomethod() function which needs four parameters). If any +function has the OVERLOAD: keyword, several additional lines +will be defined in the c file generated by xsubpp in order to +register with the overload magic. + +Since blessed objects are actually stored as RV's, it is useful +to use the typemap features to preprocess parameters and extract +the actual SV stored within the blessed RV. See the sample for +T_PTROBJ_SPECIAL below. + +To use the OVERLOAD: keyword, create an XS function which takes +three input parameters ( or use the c style '...' definition) like +this: + + SV * + cmp (lobj, robj, swap) + My_Module_obj lobj + My_Module_obj robj + IV swap + OVERLOAD: cmp <=> + { /* function defined here */} + +In this case, the function will overload both of the three way +comparison operators. For all overload operations using non-alpha +characters, you must type the parameter without quoting, seperating +multiple overloads with whitespace. Note that "" (the stringify +overload) should be entered as \"\" (i.e. escaped). + =head2 The INTERFACE: Keyword This keyword declares the current XSUB as a keeper of the given