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// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/torque/earley-parser.h"
#include "test/unittests/test-utils.h"
namespace v8 {
namespace internal {
namespace torque {
namespace {
template <int op(int, int)>
base::Optional<ParseResult> MakeBinop(ParseResultIterator* child_results) {
// Ideally, we would want to use int as a result type here instead of
// std::string. This is possible, but requires adding int to the list of
// supported ParseResult types in torque-parser.cc. To avoid changing that
// code, we use std::string here, which is already used in the Torque parser.
auto a = child_results->NextAs<std::string>();
auto b = child_results->NextAs<std::string>();
return ParseResult{std::to_string(op(std::stoi(a), std::stoi(b)))};
}
int plus(int a, int b) { return a + b; }
int minus(int a, int b) { return a - b; }
int mul(int a, int b) { return a * b; }
} // namespace
struct SimpleArithmeticGrammar : Grammar {
static bool MatchWhitespace(InputPosition* pos) {
while (MatchChar(std::isspace, pos)) {
}
return true;
}
static bool MatchInteger(InputPosition* pos) {
InputPosition current = *pos;
MatchString("-", ¤t);
if (MatchChar(std::isdigit, ¤t)) {
while (MatchChar(std::isdigit, ¤t)) {
}
*pos = current;
return true;
}
return false;
}
SimpleArithmeticGrammar() : Grammar(&sum_expression) {
SetWhitespace(MatchWhitespace);
}
Symbol integer = {Rule({Pattern(MatchInteger)}, YieldMatchedInput)};
Symbol atomic_expression = {Rule({&integer}),
Rule({Token("("), &sum_expression, Token(")")})};
Symbol mul_expression = {
Rule({&atomic_expression}),
Rule({&mul_expression, Token("*"), &atomic_expression}, MakeBinop<mul>)};
Symbol sum_expression = {
Rule({&mul_expression}),
Rule({&sum_expression, Token("+"), &mul_expression}, MakeBinop<plus>),
Rule({&sum_expression, Token("-"), &mul_expression}, MakeBinop<minus>)};
};
TEST(EarleyParser, SimpleArithmetic) {
SimpleArithmeticGrammar grammar;
SourceFileMap::Scope source_file_map;
CurrentSourceFile::Scope current_source_file{
SourceFileMap::AddSource("dummy_filename")};
std::string result1 =
grammar.Parse("-5 - 5 + (3 + 5) * 2")->Cast<std::string>();
ASSERT_EQ("6", result1);
std::string result2 = grammar.Parse("((-1 + (1) * 2 + 3 - 4 * 5 + -6 * 7))")
->Cast<std::string>();
ASSERT_EQ("-58", result2);
}
} // namespace torque
} // namespace internal
} // namespace v8
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