traxys/tree-sitter
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Don't use exceptions in pattern parser

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This commit is contained in:
Max Brunsfeld 2014-03-04 12:36:38 -08:00
parent 7ff690371e
commit ae82b90fdb
1 changed files with 19 additions and 13 deletions
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32
src/compiler/rules/pattern.cpp
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@ -52,21 +52,25 @@ namespace tree_sitter {
case '(':
next();
result = rule();
if (peek() != ')')
error("mismatched parens");
else
next();
if (has_error()) return result;
if (peek() != ')') {
error = "mismatched parens";
return result;
}
next();
break;
case '[':
next();
result = char_set().copy();
if (peek() != ']')
error("mismatched square brackets");
else
next();
if (has_error()) return result;
if (peek() != ']') {
error = "mismatched square brackets";
return result;
}
next();
break;
case ')':
error("mismatched parens");
error = "mismatched parens";
break;
default:
result = single_char().copy();
@ -87,11 +91,12 @@ namespace tree_sitter {
}
CharacterSet single_char() {
CharacterSet value({ '\0' });
CharacterSet value;
switch (peek()) {
case '\\':
next();
value = escaped_char(peek());
if (has_error()) return value;
next();
break;
default:
@ -119,7 +124,7 @@ namespace tree_sitter {
case 'd':
return CharacterSet({CharacterRange('0', '9')});
default:
error("unrecognized escape sequence");
error = "unrecognized escape sequence";
return CharacterSet();
}
}
@ -136,10 +141,11 @@ namespace tree_sitter {
return position < length;
}
void error(const char *message) {
throw string("Invalid regex pattern '") + input + "': " + message;
bool has_error() {
return error != "";
}
string error;
const string input;
const size_t length;
int position;