diff options
Diffstat (limited to 'plugins/regex.c')
| -rw-r--r-- | plugins/regex.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/plugins/regex.c b/plugins/regex.c new file mode 100644 index 0000000..d7a8a97 --- /dev/null +++ b/plugins/regex.c @@ -0,0 +1,226 @@ + +#include "zprep_plugin.h" +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> + +static void emit_match_logic(const char *pattern, FILE *out, int *label_counter); + +void regex_transpile(const char *input_body, const ZApi *api) +{ + FILE *out = api->out; + const char *p = input_body; + static int regex_counter = 0; + + // Trim whitespace from start/end of pattern block + while (*p && isspace(*p)) + { + p++; + } + char *pattern = strdup(p); + int len = strlen(pattern); + while (len > 0 && isspace(pattern[len - 1])) + { + pattern[--len] = 0; + } + + // Generate unique function name + int fn_id = regex_counter++; + char fn_name[64]; + snprintf(fn_name, sizeof(fn_name), "_regex_match_%d", fn_id); + + FILE *target = api->hoist_out ? api->hoist_out : out; + + fprintf(target, "static int %s(const char *text) {\n", fn_name); + fprintf(target, " if (!text) return 0;\n"); + fprintf(target, " const char *c = text;\n"); + + int label_id = 0; + emit_match_logic(pattern, target, &label_id); + + fprintf(target, " return 1;\n"); + fprintf(target, "}\n"); + + fprintf(out, "%s", fn_name); + + free(pattern); +} + +static void emit_match_logic(const char *pattern, FILE *out, int * /*label_counter*/) +{ + const char *c = pattern; + + while (*c) + { + if (isspace(*c)) + { + c++; + continue; + } + + // Handle Anchors + if (*c == '^') + { + c++; + continue; + } + + if (*c == '$') + { + fprintf(out, " if (*c != '\\0') return 0;\n"); + c++; + continue; + } + + // Character Class [a-z] + if (*c == '[') + { + const char *scanner = c + 1; + while (*scanner && *scanner != ']') + { + scanner++; + } + if (!*scanner) + { + return; + } + const char *class_end = scanner; + + const char *q = class_end + 1; + while (*q && isspace(*q)) + { + q++; + } + char quantifier = 0; + if (*q == '+' || *q == '*') + { + quantifier = *q; + } + + fprintf(out, " {\n"); + fprintf(out, " int _count = 0;\n"); + if (quantifier) + { + fprintf(out, " while (1) {\n"); + } + + if (quantifier) + { + fprintf(out, " if (*c == 0) break;\n"); // End of input for loop + } + else + { + fprintf(out, " if (*c == 0) return 0;\n"); // End of input for single char + } + + fprintf(out, " int match = 0;\n"); + + const char *p = c + 1; + int invert = 0; + while (p < class_end && isspace(*p)) + { + p++; + } + if (p < class_end && *p == '^') + { + invert = 1; + p++; + } + while (p < class_end && isspace(*p)) + { + p++; + } + + while (p < class_end) + { + if (isspace(*p)) + { + p++; + continue; + } + + // Range check + const char *next = p + 1; + while (next < class_end && isspace(*next)) + { + next++; + } + + if (next < class_end && *next == '-' && next + 1 < class_end) + { + const char *range_end = next + 1; + while (range_end < class_end && isspace(*range_end)) + { + range_end++; + } + + if (range_end < class_end) + { + fprintf(out, " if (*c >= '%c' && *c <= '%c') match = 1;\n", *p, + *range_end); + p = range_end + 1; + continue; + } + } + + fprintf(out, " if (*c == '%c') match = 1;\n", *p); + p++; + } + + if (invert) + { + fprintf(out, " if (match) { match = 0; } else { match = 1; }\n"); + } + + if (quantifier) + { + fprintf(out, " if (!match) break;\n"); + fprintf(out, " c++; _count++;\n"); + fprintf(out, " }\n"); // End while + if (quantifier == '+') + { + fprintf(out, " if (_count == 0) return 0;\n"); + } + } + else + { + fprintf(out, " if (!match) return 0;\n"); + fprintf(out, " c++;\n"); + } + + fprintf(out, " }\n"); // End Block + + // Advance main pointer c + c = class_end + 1; + if (quantifier) + { + // Skip the quantifier token we processed + while (*c && isspace(*c)) + { + c++; + } + if (*c == quantifier) + { + c++; + } + } + continue; + } + + // Dot + if (*c == '.') + { + fprintf(out, " if (*c == 0) return 0; c++;\n"); + c++; + continue; + } + + // Literal + char lit = *c; + fprintf(out, " if (*c != '%c') return 0; c++;\n", lit); + c++; + } +} + +ZPlugin regex_plugin = {.name = "regex", .fn = regex_transpile}; |