Working up parser combinators
This commit is contained in:
61
langkit/langkit_parser.cpp
Normal file
61
langkit/langkit_parser.cpp
Normal file
@@ -0,0 +1,61 @@
|
||||
// This file is distributed under the BSD License.
|
||||
// See LICENSE.TXT for details.
|
||||
|
||||
#include "langkit_lexer.hpp"
|
||||
#include "langkit_parser.hpp"
|
||||
|
||||
Token_Iterator String_Rule(Token_Iterator iter, Token_Iterator end, const std::string &val) {
|
||||
if (iter != end) {
|
||||
if (iter->text == val) {
|
||||
return ++iter;
|
||||
}
|
||||
}
|
||||
|
||||
return iter;
|
||||
}
|
||||
|
||||
Token_Iterator Type_Rule(Token_Iterator iter, Token_Iterator end, const int val) {
|
||||
if (iter != end) {
|
||||
if (iter->identifier == val) {
|
||||
return ++iter;
|
||||
}
|
||||
}
|
||||
|
||||
return iter;
|
||||
}
|
||||
|
||||
Token_Iterator Or_Rule(Token_Iterator iter, Token_Iterator end, const Rule &lhs, const Rule &rhs) {
|
||||
Token_Iterator new_iter;
|
||||
|
||||
if (iter != end) {
|
||||
new_iter = lhs.rule(iter, end);
|
||||
|
||||
if (new_iter != iter) {
|
||||
return new_iter;
|
||||
}
|
||||
else {
|
||||
new_iter = rhs.rule(iter, end);
|
||||
if (new_iter != iter) {
|
||||
return new_iter;
|
||||
}
|
||||
}
|
||||
}
|
||||
return iter;
|
||||
}
|
||||
|
||||
Token_Iterator And_Rule(Token_Iterator iter, Token_Iterator end, const Rule &lhs, const Rule &rhs) {
|
||||
Token_Iterator lhs_iter, rhs_iter;
|
||||
|
||||
if (iter != end) {
|
||||
lhs_iter = lhs.rule(iter, end);
|
||||
|
||||
if (lhs_iter != iter) {
|
||||
rhs_iter = rhs.rule(iter, end);
|
||||
if (rhs_iter != iter) {
|
||||
return rhs_iter;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return iter;
|
||||
}
|
Reference in New Issue
Block a user