diff options
Diffstat (limited to 'bpeg.c')
| -rw-r--r-- | bpeg.c | 111 |
1 files changed, 63 insertions, 48 deletions
@@ -323,6 +323,48 @@ static vm_op_t *expand_choices(vm_op_t *first) return expand_choices(choice); } +static char escapechar(const char *escaped, const char **end) +{ + size_t len = 1; + char ret = *escaped; + switch (*escaped) { + case 'a': ret = '\a'; break; case 'b': ret = '\b'; break; + case 'n': ret = '\n'; break; case 'r': ret = '\r'; break; + case 't': ret = '\t'; break; case 'v': ret = '\v'; break; + case 'x': { // Hex + static const char hextable[255] = { + ['0']=0x10, ['1']=0x1, ['2']=0x2, ['3']=0x3, ['4']=0x4, + ['5']=0x5, ['6']=0x6, ['7']=0x7, ['8']=0x8, ['9']=0x9, + ['a']=0xa, ['b']=0xb, ['c']=0xc, ['d']=0xd, ['e']=0xe, ['f']=0xf, + ['A']=0xa, ['B']=0xb, ['C']=0xc, ['D']=0xd, ['E']=0xe, ['F']=0xf, + }; + if (hextable[(int)escaped[1]] && hextable[(int)escaped[2]]) { + ret = (hextable[(int)escaped[1]] << 4) | (hextable[(int)escaped[2]] & 0xF); + len = 3; + } + break; + } + case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': { // Octal + ret = escaped[0] - '0'; + if ('0' <= escaped[1] && escaped[1] <= '7') { + ++len; + ret = (ret << 3) | (escaped[1] - '0'); + if ('0' <= escaped[2] && escaped[2] <= '7') { + ++len; + ret = (ret << 3) | (escaped[2] - '0'); + } + } + break; + } + default: break; + } + *end = &escaped[len]; + return ret; +} + +/* + * Compile a string of BPEG code into virtual machine opcodes + */ static vm_op_t *compile_bpeg(const char *str) { if (!*str) return NULL; @@ -369,43 +411,7 @@ static vm_op_t *compile_bpeg(const char *str) check(*str, "Expected escape after '\\'"); op->op = VM_STRING; op->len = 1; - char c[2] = {*str, '\0'}; - ++str; - switch (c[0]) { - case 'a': c[0] = '\a'; break; - case 'b': c[0] = '\b'; break; - case 'n': c[0] = '\n'; break; - case 'r': c[0] = '\r'; break; - case 't': c[0] = '\t'; break; - case 'v': c[0] = '\v'; break; - case 'x': { // Hex - static const char hextable[255] = { - ['0']=0x10, ['1']=0x1, ['2']=0x2, ['3']=0x3, ['4']=0x4, - ['5']=0x5, ['6']=0x6, ['7']=0x7, ['8']=0x8, ['9']=0x9, - ['a']=0xa, ['b']=0xb, ['c']=0xc, ['d']=0xd, ['e']=0xe, ['f']=0xf, - ['A']=0xa, ['B']=0xb, ['C']=0xc, ['D']=0xd, ['E']=0xe, ['F']=0xf, - }; - if (hextable[(int)str[1]] && hextable[(int)str[2]]) - c[0] = (hextable[(int)str[1]] << 4) | (hextable[(int)str[2]] & 0xF); - break; - } - case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': { // Octal - c[0] = c[0] - '0'; - ++str; - if ('0' <= *str && *str <= '7') { - c[0] = (c[0] << 3) | (*str - '0'); - ++str; - } - if ('0' <= *str && *str <= '7') { - c[0] = (c[0] << 3) | (*str - '0'); - ++str; - } - break; - } - default: { - check(0, "Invalid escape sequence"); - } - } + char c[2] = {escapechar(str, &str), '\0'}; op->args.s = strdup(c); break; } @@ -615,19 +621,24 @@ static vm_op_t *compile_bpeg(const char *str) str = after_spaces(str); char quote = *str; - ++str; - check(quote == '\'' || quote == '"', - "Expected string literal for replacement"); - const char *replacement = str; - for (; *str && *str != quote; str++) { - if (*str == '\\') { - check(str[1], "Expected more string contents after backslash"); - ++str; + const char *replacement; + if (quote == '}') { + replacement = strdup(""); + } else { + ++str; + check(quote == '\'' || quote == '"', + "Expected string literal for replacement"); + replacement = str; + for (; *str && *str != quote; str++) { + if (*str == '\\') { + check(str[1], "Expected more string contents after backslash"); + ++str; + } } + replacement = strndup(replacement, (size_t)(str-replacement)); + ++str; + str = after_spaces(str); } - replacement = strndup(replacement, (size_t)(str-replacement)); - ++str; - str = after_spaces(str); check(*str == '}', "Expected a closing '}'"); ++str; op->op = VM_REPLACE; @@ -755,6 +766,10 @@ static void print_match(match_t *m, const char *color) print_match(cap, "\033[0;7;35m"); printf("\033[0;7;34m"); } + } else if (*r == '\\') { + ++r; + fputc(escapechar(r, &r), stdout); + --r; } else { fputc(*r, stdout); } |