diff options
Diffstat (limited to 'grammar.c')
| -rw-r--r-- | grammar.c | 37 |
1 files changed, 25 insertions, 12 deletions
@@ -7,6 +7,14 @@ #include "utils.h" const char *BPEG_BUILTIN_GRAMMAR = ( + // Meta-rules for acting on everything + "pattern = !(/);\n" // Not defined by default + "replacement = {!(/)=>};\n" // Not defined by default + "replace-all = *&&@replacement &&$$;\n" + "find-all = *(matching-line / {&&(\\n/$$)=>});\n" + "matching-line = +&@pattern *. $ ?\\n;\n" + + // Helper definitions (commonly used) "crlf=\\r\\n;\n" "cr=\\r;\n" "r=\\r;\n" "anglebraces=`< *(anglebraces / ~~`>) `>;\n" @@ -61,9 +69,13 @@ void add_def(grammar_t *g, const char *src, const char *name, vm_op_t *op) ++g->size; } -void load_grammar(grammar_t *g, const char *src) +/* + * Load the given grammar (semicolon-separated definitions) + * and return the first rule defined. + */ +vm_op_t *load_grammar(grammar_t *g, const char *src) { - vm_op_t *mainpat = NULL; + vm_op_t *ret = NULL; do { src = after_spaces(src); if (!*src) break; @@ -76,20 +88,21 @@ void load_grammar(grammar_t *g, const char *src) vm_op_t *op = bpeg_pattern(src); check(op, "Couldn't load definition"); add_def(g, src, name, op); - if (mainpat == NULL) { - mainpat = op; - g->pattern = op; + if (ret == NULL) { + ret = op; } src = op->end; } while (*src && matchchar(&src, ';')); + return ret; } -/* - * Print a BPEG grammar in human-readable form. - */ -void print_grammar(grammar_t *g) +vm_op_t *lookup(grammar_t *g, const char *name) { - if (g->pattern) print_pattern(g->pattern); + // Search backwards so newer defs take precedence + for (int i = g->size-1; i >= 0; i--) { + if (streq(g->definitions[i].name, name)) { + return g->definitions[i].op; + } + } + return NULL; } - -// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1 |