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#include "EXTERN.h"
#include "perl.h"
#include "callparser1.h"
#include "XSUB.h"
#define REENTER_PARSER STMT_START { \
ENTER; \
PL_curcop = &PL_compiling; \
SAVEVPTR(PL_op); \
} STMT_END
#define LEAVE_PARSER LEAVE
static OP *parser_callback(pTHX_ GV *namegv, SV *psobj, U32 *flagsp)
{
dSP;
SV *args_generator;
SV *statement = NULL;
I32 count;
// call the parser callback
// it should take no arguments and return a coderef which, when called,
// produces the arguments to the keyword function
// the optree we want to generate is for something like
// mykeyword($code->())
// where $code is the thing returned by the parser function
PUSHMARK(SP);
count = call_sv(psobj, G_ARRAY);
SPAGAIN;
if (count > 1) {
statement = POPs;
}
args_generator = SvREFCNT_inc(POPs);
PUTBACK;
if (!SvROK(args_generator) || SvTYPE(SvRV(args_generator)) != SVt_PVCV) {
croak("The parser function for %s must return a coderef, not %"SVf,
GvNAME(namegv), args_generator);
}
if (SvTRUE(statement)) {
*flagsp |= CALLPARSER_STATEMENT;
}
return newUNOP(OP_ENTERSUB, OPf_STACKED,
newCVREF(0,
Perl_scalar(newSVOP(OP_CONST, 0,
args_generator))));
}
// we will need helper functions for
// - lexer functions
// - lex_read_space
// - lex_peek_unichar
// - lex_stuff_sv
// - parser functions (OP* return values should become coderefs)
// - parse_arithexpr
// - parse_barestmt
// - parse_block
// - parse_fullexpr
// - parse_fullstmt
// - parse_label
// - parse_listexpr
// - parse_stmtseq
// - parse_termexpr
// - random other things
// - "read a variable name"
// - "read a quoted string"
// - "create a new lexical variable" (should return a reference to it)
MODULE = Parse::Keyword PACKAGE = Parse::Keyword
PROTOTYPES: DISABLE
void
install_keyword_handler(keyword, handler)
SV *keyword
SV *handler
CODE:
cv_set_call_parser((CV*)SvRV(keyword), parser_callback, handler);
void
lex_read_space()
CODE:
PL_curcop = &PL_compiling;
lex_read_space(0);
SV *
parse_block()
PREINIT:
I32 floor;
CV *code;
CODE:
REENTER_PARSER;
floor = start_subparse(0, CVf_ANON);
code = newATTRSUB(floor, NULL, NULL, NULL, parse_block(0));
LEAVE_PARSER;
if (CvCLONE(code)) {
code = cv_clone(code);
}
RETVAL = newRV_inc((SV*)code);
OUTPUT:
RETVAL
SV *
lex_peek(len)
UV len
CODE:
PL_curcop = &PL_compiling;
while (PL_parser->bufend - PL_parser->bufptr < len) {
if (!lex_next_chunk(LEX_KEEP_PREVIOUS)) {
break;
}
}
if (PL_parser->bufend - PL_parser->bufptr < len) {
len = PL_parser->bufend - PL_parser->bufptr;
}
RETVAL = newSVpvn(PL_parser->bufptr, len); /* XXX unicode? */
OUTPUT:
RETVAL
void
lex_read(len)
UV len
CODE:
PL_curcop = &PL_compiling;
lex_read_to(PL_parser->bufptr + len);
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