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/*
* Copyright 2017 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef wasm_support_name_h
#define wasm_support_name_h
#include "support/istring.h"
namespace wasm {
// We use a Name for all of the identifiers. These are IStrings, so they are
// all interned - comparisons etc are just pointer comparisons, so there is no
// perf loss. Having names everywhere makes using the AST much nicer (for
// example, block names are strings and not offsets, which makes composition
// - adding blocks, removing blocks - easy). One exception is local variables,
// where we do use indices, as they are a large proportion of the AST,
// perf matters a lot there, and compositionality is not a problem.
// TODO: as an optimization, IString values < some threshold could be considered
// numerical indices directly.
struct Name : public IString {
Name() : IString() {}
Name(std::string_view str) : IString(str, false) {}
Name(const char* str) : IString(str, false) {}
Name(IString str) : IString(str) {}
Name(const std::string& str) : IString(str) {}
// String literals do not need to be copied. Note: Not safe to construct from
// temporary char arrays! Take their address first.
template<size_t N> Name(const char (&str)[N]) : IString(str) {}
friend std::ostream& operator<<(std::ostream& o, Name name) {
if (name) {
return o << name.str;
} else {
return o << "(null Name)";
}
}
static Name fromInt(size_t i) {
return IString(std::to_string(i).c_str(), false);
}
bool hasSubstring(IString substring) {
// TODO: Use C++23 `contains`.
return str.find(substring.str) != std::string_view::npos;
}
std::ostream& print(std::ostream& o) const;
private:
static bool isIDChar(char c);
};
} // namespace wasm
namespace std {
template<> struct hash<wasm::Name> : hash<wasm::IString> {};
} // namespace std
#endif // wasm_support_name_h