traxys/tree-sitter
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Parse simple character sets in pattern rules

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This commit is contained in:
Max Brunsfeld 2014-01-30 13:04:31 -08:00
parent 28e10dc722
commit 60e2d00b4d
6 changed files with 192 additions and 127 deletions
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56
src/compiler/rules/pattern.cpp
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@ -38,6 +38,18 @@ namespace tree_sitter {
return result;
}
rule_ptr char_set() {
bool is_affirmative = true;
if (peek() == '^') {
next();
is_affirmative = false;
}
std::vector<CharacterMatch> matches;
while (has_more_input() && (peek() != ']'))
matches.push_back(single_char());
return character(matches, is_affirmative);
}
rule_ptr atom() {
rule_ptr result;
switch (peek()) {
@ -49,34 +61,52 @@ namespace tree_sitter {
else
next();
break;
case '[':
next();
result = char_set();
if (peek() != ']')
error("mismatched square brackets");
else
next();
break;
case ')':
error("mismatched parens");
break;
case '\\':
next();
result = escaped_char(peek());
next();
break;
default:
result = character(peek());
next();
break;
result = character({ single_char() }, true);
}
return result;
}
rule_ptr escaped_char(char value) {
CharacterMatch single_char() {
CharacterMatch value('\0');
switch (peek()) {
case '\\':
next();
value = escaped_char(peek());
next();
break;
default:
value = peek();
next();
return value;
}
return value;
}
CharacterMatch escaped_char(char value) {
switch (value) {
case '\\':
case '(':
case ')':
return character(value);
return value;
case 'w':
return character(CharClassWord);
return CharClassWord;
case 'd':
return character(CharClassDigit);
return CharClassDigit;
default:
error("unrecognized escape sequence");
return rule_ptr();
return '\0';
}
}