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-rw-r--r--bpeg.c144
-rw-r--r--utils.h32
2 files changed, 77 insertions, 99 deletions
diff --git a/bpeg.c b/bpeg.c
index 674e1ba..3af2b78 100644
--- a/bpeg.c
+++ b/bpeg.c
@@ -253,27 +253,6 @@ static void set_range(vm_op_t *op, ssize_t min, ssize_t max, vm_op_t *pat, vm_op
op->args.repetitions.sep = sep;
}
-/*
- * Helper function to skip past all spaces (and comments)
- * Returns a pointer to the first non-space character.
- */
-static inline const char *after_spaces(const char *str)
-{
- // Skip whitespace and comments:
- skip_whitespace:
- switch (*str) {
- case ' ': case '\r': case '\n': case '\t': {
- ++str;
- goto skip_whitespace;
- }
- case '#': {
- while (*str && *str != '\n') ++str;
- goto skip_whitespace;
- }
- }
- return str;
-}
-
/*
* Take an opcode and expand it into a chain of patterns if it's
* followed by any patterns (e.g. "`x `y"), otherwise return
@@ -305,9 +284,8 @@ static vm_op_t *expand_chain(vm_op_t *first)
static vm_op_t *expand_choices(vm_op_t *first)
{
first = expand_chain(first);
- const char *str = after_spaces(first->end);
- if (*str != '/') return first;
- ++str;
+ const char *str = first->end;
+ if (!matchchar(&str, '/')) return first;
debug("Otherwise:\n");
vm_op_t *second = compile_bpeg(str);
check(second, "Expected pattern after '/'");
@@ -375,10 +353,11 @@ static vm_op_t *compile_bpeg(const char *str)
vm_op_t *op = calloc(sizeof(vm_op_t), 1);
op->start = str;
op->len = -1;
- switch (*str) {
+ char c = *str;
+ ++str;
+ switch (c) {
// Any char (dot)
case '.': {
- ++str;
debug("Dot\n");
op->op = VM_ANYCHAR;
op->len = 1;
@@ -386,46 +365,41 @@ static vm_op_t *compile_bpeg(const char *str)
}
// Char literals
case '`': {
+ char literal[2] = {*str, '\0'};
++str;
- char c[2] = {*str, '\0'};
- ++str;
- check(c[0], "Expected character after '`'\n");
+ check(literal[0], "Expected character after '`'\n");
op->len = 1;
- if (*str == ',') { // Range
+ if (matchchar(&str, ',')) { // Range
debug("Char range\n");
- ++str;
char c2 = *str;
check(c2, "Expected character after ','");
op->op = VM_RANGE;
- op->args.range.low = c[0];
+ op->args.range.low = literal[0];
op->args.range.high = c2;
++str;
} else {
debug("Char literal\n");
op->op = VM_STRING;
- op->args.s = strdup(c);
+ op->args.s = strdup(literal);
}
break;
}
// Escapes
case '\\': {
- ++str;
debug("Escape sequence\n");
check(*str, "Expected escape after '\\'");
op->op = VM_STRING;
op->len = 1;
- char c[2] = {escapechar(str, &str), '\0'};
- op->args.s = strdup(c);
+ char literal[2] = {escapechar(str, &str), '\0'};
+ op->args.s = strdup(literal);
break;
}
// String literal
case '"': case '\'': {
- char quote = *str;
- ++str;
+ char quote = c;
const char *literal = str;
for (; *str && *str != quote; str++) {
if (*str == '\\') {
- // TODO: handle escape chars like \n
check(str[1], "Expected more string contents after backslash");
++str;
}
@@ -433,14 +407,13 @@ static vm_op_t *compile_bpeg(const char *str)
op->op = VM_STRING;
op->len = (ssize_t)(str - literal);
op->args.s = strndup(literal, (size_t)op->len);
+ // TODO: handle escape chars like \n
debug("String literal: %c%s%c\n", quote, op->args.s, quote);
- check(*str == quote, "Missing closing quote");
- ++str;
+ check(matchchar(&str, quote), "Missing closing quote");
break;
}
// Not <pat>
case '!': {
- ++str;
debug("Not pattern\n");
vm_op_t *p = compile_bpeg(str);
check(p, "Expected pattern after '!'\n");
@@ -452,7 +425,6 @@ static vm_op_t *compile_bpeg(const char *str)
}
// Upto <pat>
case '^': {
- ++str;
debug("Upto pattern\n");
vm_op_t *p = compile_bpeg(str);
check(p, "Expected pattern after '^'\n");
@@ -464,7 +436,6 @@ static vm_op_t *compile_bpeg(const char *str)
}
// Upto and including <pat>
case '&': {
- ++str;
debug("Upto-and pattern\n");
vm_op_t *p = compile_bpeg(str);
check(p, "Expected pattern after '&'\n");
@@ -479,34 +450,24 @@ static vm_op_t *compile_bpeg(const char *str)
case '6': case '7': case '8': case '9': {
debug("Repetitions\n");
ssize_t min = -1, max = -1;
+ --str;
long n1 = strtol(str, (char**)&str, 10);
- str = after_spaces(str);
- switch (*str) {
- case '-': {
- ++str;
- str = after_spaces(str);
- const char *start = str;
- long n2 = strtol(str, (char**)&str, 10);
- if (str == start) min = 0, max = n1;
- else min = n1, max = n2;
- break;
- }
- case '+': {
- ++str;
- min = n1, max = -1;
- break;
- }
- default: {
- min = n1, max = n1;
- break;
- }
+ if (matchchar(&str, '-')) {
+ str = after_spaces(str);
+ const char *start = str;
+ long n2 = strtol(str, (char**)&str, 10);
+ if (str == start) min = 0, max = n1;
+ else min = n1, max = n2;
+ } else if (matchchar(&str, '+')) {
+ min = n1, max = -1;
+ } else {
+ min = n1, max = n1;
}
vm_op_t *pat = compile_bpeg(str);
check(pat, "Expected pattern after repetition count");
str = pat->end;
str = after_spaces(str);
- if (*str == '%') {
- ++str;
+ if (matchchar(&str, '%')) {
vm_op_t *sep = compile_bpeg(str);
check(sep, "Expected pattern for separator after '%%'");
str = sep->end;
@@ -521,18 +482,16 @@ static vm_op_t *compile_bpeg(const char *str)
case '+': case '*': case '?': {
debug("Special repetitions\n");
ssize_t min = -1, max = -1;
- switch (*str) {
+ switch (c) {
case '+': min = 1, max = -1; break;
case '*': min = 0, max = -1; break;
case '?': min = 0, max = 1; break;
}
- ++str;
vm_op_t *pat = compile_bpeg(str);
check(pat, "Expected pattern after +");
str = pat->end;
str = after_spaces(str);
- if (*str == '%') {
- ++str;
+ if (matchchar(&str, '%')) {
vm_op_t *sep = compile_bpeg(str);
check(sep, "Expected pattern for separator after '%%'");
str = sep->end;
@@ -545,7 +504,6 @@ static vm_op_t *compile_bpeg(const char *str)
}
// Lookbehind
case '<': {
- ++str;
debug("Lookbehind\n");
vm_op_t *pat = compile_bpeg(str);
check(pat, "Expected pattern after <");
@@ -559,7 +517,6 @@ static vm_op_t *compile_bpeg(const char *str)
}
// Lookahead
case '>': {
- ++str;
debug("Lookahead\n");
vm_op_t *pat = compile_bpeg(str);
check(pat, "Expected pattern after >");
@@ -572,32 +529,28 @@ static vm_op_t *compile_bpeg(const char *str)
// Parentheses
case '(': {
debug("Open paren (\n");
- ++str;
free(op);
op = compile_bpeg(str);
check(op, "Expected pattern inside parentheses");
op = expand_choices(op);
str = op->end;
str = after_spaces(str);
- check(*str == ')', "Expected closing parenthesis");
- ++str;
+ check(matchchar(&str, ')'), "Expected closing parenthesis");
debug(")\n");
break;
}
// Capture
case '@': {
debug("Capture\n");
- ++str;
op->op = VM_CAPTURE;
str = after_spaces(str);
- if (*str == '[') {
- ++str;
+ if (matchchar(&str, '[')) {
char *closing = strchr(str, ']');
check(closing, "Expected closing ']'");
op->args.capture.name = strndup(str, (size_t)(closing-str));
debug("named \"%s\"\n", op->args.capture.name);
str = closing;
- ++str;
+ check(matchchar(&str, ']'), "Expected closing ']'");
}
vm_op_t *pat = compile_bpeg(str);
check(pat, "Expected pattern after @");
@@ -609,27 +562,24 @@ static vm_op_t *compile_bpeg(const char *str)
// Replacement
case '{': {
debug("Replacement {\n");
- ++str;
str = after_spaces(str);
vm_op_t *pat = NULL;
- if (*str != '~') {
+ if (!matchchar(&str, '~')) {
pat = compile_bpeg(str);
check(pat, "Expected pattern after '{'");
pat = expand_choices(pat);
str = pat->end;
str = after_spaces(str);
- check(*str == '~', "Expected '~' after pattern in replacement");
+ check(matchchar(&str, '~'), "Expected '~' after pattern in replacement");
}
- ++str;
str = after_spaces(str);
char quote = *str;
const char *replacement;
- if (quote == '}') {
+ if (matchchar(&str, '}')) {
replacement = strdup("");
} else {
- ++str;
- check(quote == '\'' || quote == '"',
+ check(matchchar(&str, '"') || matchchar(&str, '\''),
"Expected string literal for replacement");
replacement = str;
for (; *str && *str != quote; str++) {
@@ -639,11 +589,9 @@ static vm_op_t *compile_bpeg(const char *str)
}
}
replacement = strndup(replacement, (size_t)(str-replacement));
- ++str;
- str = after_spaces(str);
+ check(matchchar(&str, quote), "Expected closing quote");
}
- check(*str == '}', "Expected a closing '}'");
- ++str;
+ check(matchchar(&str, '}'), "Expected a closing '}'");
op->op = VM_REPLACE;
op->args.replace.replace_pat = pat;
op->args.replace.replacement = replacement;
@@ -655,14 +603,14 @@ static vm_op_t *compile_bpeg(const char *str)
// Whitespace
case '_': {
debug("Whitespace\n");
- ++str;
op->op = VM_REF;
op->args.s = strdup("_");
break;
}
default: {
// Reference
- if (isalpha(*str)) {
+ if (isalpha(c)) {
+ --str;
const char *refname = str;
size_t len = 1;
for (++str; isalnum(*str); ++str)
@@ -770,8 +718,7 @@ static void print_match(match_t *m, const char *color)
print_match(cap, "\033[0;35m");
printf("\033[0;34m");
}
- } else if (*r == '\\') {
- ++r;
+ } else if (matchchar(&r, '\\')) {
fputc(escapechar(r, &r), stdout);
--r;
} else {
@@ -819,16 +766,15 @@ int main(int argc, char *argv[])
check(op, "Failed to compile_bpeg input");
op = expand_choices(op);
- const char *defs = after_spaces(op->end);
- while (*defs == ';') {
- defs = after_spaces(++defs);
+ const char *defs = op->end;
+ while (matchchar(&defs, ';')) {
+ defs = after_spaces(defs);
const char *name = defs;
check(isalpha(*name), "Definition must begin with a name");
while (isalpha(*defs)) ++defs;
name = strndup(name, (size_t)(defs-name));
defs = after_spaces(defs);
- check(*defs == '=', "Expected '=' in definition");
- ++defs;
+ check(matchchar(&defs, '='), "Expected '=' in definition");
vm_op_t *def = load_def(name, defs);
check(def, "Couldn't load definition");
defs = def->end;
diff --git a/utils.h b/utils.h
index 8723516..96c6de2 100644
--- a/utils.h
+++ b/utils.h
@@ -5,3 +5,35 @@
// TODO: better error reporting
#define check(cond, ...) do { if (!(cond)) { fprintf(stderr, __VA_ARGS__); fwrite("\n", 1, 1, stderr); _exit(1); } } while(0)
#define debug(...) do { if (verbose) fprintf(stderr, __VA_ARGS__); } while(0)
+
+/*
+ * Helper function to skip past all spaces (and comments)
+ * Returns a pointer to the first non-space character.
+ */
+static inline const char *after_spaces(const char *str)
+{
+ // Skip whitespace and comments:
+ skip_whitespace:
+ switch (*str) {
+ case ' ': case '\r': case '\n': case '\t': {
+ ++str;
+ goto skip_whitespace;
+ }
+ case '#': {
+ while (*str && *str != '\n') ++str;
+ goto skip_whitespace;
+ }
+ }
+ return str;
+}
+
+static inline int matchchar(const char **str, char c)
+{
+ *str = after_spaces(*str);
+ if (**str == c) {
+ ++(*str);
+ return 1;
+ } else {
+ return 0;
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2026-03-01 05:04:33 +0000