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// Copyright 2020 The Tint Authors.
//
// 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 SRC_TINT_READER_WGSL_TOKEN_H_
#define SRC_TINT_READER_WGSL_TOKEN_H_
#include <string>
#include <string_view>
#include <variant>
#include "src/tint/source.h"
namespace tint::reader::wgsl {
/// Stores tokens generated by the Lexer
class Token {
public:
/// The type of the parsed token
enum class Type {
/// Error result
kError = -2,
/// Uninitialized token
kUninitialized = 0,
/// Placeholder token which maybe filled in later
kPlaceholder = 1,
/// End of input string reached
kEOF,
/// An identifier
kIdentifier,
/// A float literal with no suffix
kFloatLiteral,
/// A float literal with an 'f' suffix
kFloatLiteral_F,
/// A float literal with an 'h' suffix
kFloatLiteral_H,
/// An integer literal with no suffix
kIntLiteral,
/// An integer literal with an 'i' suffix
kIntLiteral_I,
/// An integer literal with a 'u' suffix
kIntLiteral_U,
/// A '&'
kAnd,
/// A '&&'
kAndAnd,
/// A '->'
kArrow,
/// A '@'
kAttr,
/// A '/'
kForwardSlash,
/// A '!'
kBang,
/// A '['
kBracketLeft,
/// A ']'
kBracketRight,
/// A '{'
kBraceLeft,
/// A '}'
kBraceRight,
/// A ':'
kColon,
/// A ','
kComma,
/// A '='
kEqual,
/// A '=='
kEqualEqual,
/// A '>' (post template-args classification)
kTemplateArgsRight,
/// A '>'
kGreaterThan,
/// A '>='
kGreaterThanEqual,
/// A '>>'
kShiftRight,
/// A '<' (post template-args classification)
kTemplateArgsLeft,
/// A '<'
kLessThan,
/// A '<='
kLessThanEqual,
/// A '<<'
kShiftLeft,
/// A '%'
kMod,
/// A '-'
kMinus,
/// A '--'
kMinusMinus,
/// A '!='
kNotEqual,
/// A '.'
kPeriod,
/// A '+'
kPlus,
/// A '++'
kPlusPlus,
/// A '|'
kOr,
/// A '||'
kOrOr,
/// A '('
kParenLeft,
/// A ')'
kParenRight,
/// A ';'
kSemicolon,
/// A '*'
kStar,
/// A '~'
kTilde,
/// A '_'
kUnderscore,
/// A '^'
kXor,
/// A '+='
kPlusEqual,
/// A '-='
kMinusEqual,
/// A '*='
kTimesEqual,
/// A '/='
kDivisionEqual,
/// A '%='
kModuloEqual,
/// A '&='
kAndEqual,
/// A '|='
kOrEqual,
/// A '^='
kXorEqual,
/// A '>>='
kShiftRightEqual,
/// A '<<='
kShiftLeftEqual,
/// A 'alias'
kAlias,
/// A 'bitcast'
kBitcast,
/// A 'break'
kBreak,
/// A 'case'
kCase,
/// A 'const'
kConst,
/// A 'const_assert'
kConstAssert,
/// A 'continue'
kContinue,
/// A 'continuing'
kContinuing,
/// A 'default'
kDefault,
/// A 'diagnostic'
kDiagnostic,
/// A 'discard'
kDiscard,
/// A 'else'
kElse,
/// A 'enable'
kEnable,
/// A 'fallthrough'
// Note, this isn't a keyword, but a reserved word. We match it as a keyword in order to
// provide better diagnostics in case a `fallthrough` is added to a case body.
kFallthrough,
/// A 'false'
kFalse,
/// A 'fn'
kFn,
// A 'for'
kFor,
/// A 'if'
kIf,
/// A 'let'
kLet,
/// A 'loop'
kLoop,
/// A 'override'
kOverride,
/// A 'requires'
kRequires,
/// A 'return'
kReturn,
/// A 'struct'
kStruct,
/// A 'switch'
kSwitch,
/// A 'true'
kTrue,
/// A 'var'
kVar,
/// A 'while'
kWhile,
};
/// Converts a token type to a name
/// @param type the type to convert
/// @returns the token type as as string
static std::string_view TypeToName(Type type);
/// Creates an uninitialized token
Token();
/// Create a Token
/// @param type the Token::Type of the token
/// @param source the source of the token
Token(Type type, const Source& source);
/// Create a string Token
/// @param type the Token::Type of the token
/// @param source the source of the token
/// @param view the source string view for the token
Token(Type type, const Source& source, const std::string_view& view);
/// Create a string Token
/// @param type the Token::Type of the token
/// @param source the source of the token
/// @param str the source string for the token
Token(Type type, const Source& source, const std::string& str);
/// Create a string Token
/// @param type the Token::Type of the token
/// @param source the source of the token
/// @param str the source string for the token
Token(Type type, const Source& source, const char* str);
/// Create a integer Token of the given type
/// @param type the Token::Type of the token
/// @param source the source of the token
/// @param val the source unsigned for the token
Token(Type type, const Source& source, int64_t val);
/// Create a double Token
/// @param type the Token::Type of the token
/// @param source the source of the token
/// @param val the source double for the token
Token(Type type, const Source& source, double val);
/// Move constructor
Token(Token&&);
~Token();
/// Equality operator with an identifier
/// @param ident the identifier string
/// @return true if this token is an identifier and is equal to ident.
bool operator==(std::string_view ident) const;
/// Sets the token to the given type
/// @param type the type to set
void SetType(Token::Type type) { type_ = type; }
/// Returns true if the token is of the given type
/// @param t the type to check against.
/// @returns true if the token is of type `t`
bool Is(Type t) const { return type_ == t; }
/// @returns true if the token is uninitialized
bool IsUninitialized() const { return type_ == Type::kUninitialized; }
/// @returns true if the token is a placeholder
bool IsPlaceholder() const { return type_ == Type::kPlaceholder; }
/// @returns true if the token is EOF
bool IsEof() const { return type_ == Type::kEOF; }
/// @returns true if the token is Error
bool IsError() const { return type_ == Type::kError; }
/// @returns true if the token is an identifier
bool IsIdentifier() const { return type_ == Type::kIdentifier; }
/// @returns true if the token is a literal
bool IsLiteral() const {
return type_ == Type::kIntLiteral || type_ == Type::kIntLiteral_I ||
type_ == Type::kIntLiteral_U || type_ == Type::kFalse || type_ == Type::kTrue ||
type_ == Type::kFloatLiteral || type_ == Type::kFloatLiteral_F ||
type_ == Type::kFloatLiteral_H;
}
/// @returns the number of placeholder tokens required to follow the token, in order to provide
/// space for token splitting.
size_t NumPlaceholders() const {
switch (type_) {
case Type::kShiftRightEqual:
return 2;
case Type::kShiftRight:
case Type::kGreaterThanEqual:
case Type::kAndAnd:
case Type::kMinusMinus:
return 1;
default:
return 0;
}
}
/// @returns true if the token is a binary operator
bool IsBinaryOperator() const {
switch (type_) {
case Type::kAnd:
case Type::kAndAnd:
case Type::kEqualEqual:
case Type::kForwardSlash:
case Type::kGreaterThan:
case Type::kGreaterThanEqual:
case Type::kLessThan:
case Type::kLessThanEqual:
case Type::kMinus:
case Type::kMod:
case Type::kNotEqual:
case Type::kOr:
case Type::kOrOr:
case Type::kPlus:
case Type::kShiftLeft:
case Type::kShiftRight:
case Type::kStar:
case Type::kXor:
return true;
default:
return false;
}
}
/// @returns the source information for this token
Source source() const { return source_; }
/// @returns the type of the token
Type type() const { return type_; }
/// Returns the string value of the token
/// @return std::string
std::string to_str() const;
/// Returns the string view of the token
/// @return std::string_view
/// @note if the token is not an identifier, an empty string_view will be returned.
std::string_view to_str_view() const;
/// Returns the float value of the token. 0 is returned if the token does not
/// contain a float value.
/// @return double
double to_f64() const;
/// Returns the int64_t value of the token. 0 is returned if the token does
/// not contain an integer value.
/// @return int64_t
int64_t to_i64() const;
/// @returns the token type as string
std::string_view to_name() const { return Token::TypeToName(type_); }
private:
/// The Token::Type of the token
Type type_ = Type::kError;
/// The source where the token appeared
Source source_;
/// The value represented by the token
std::variant<int64_t, double, std::string, std::string_view> value_;
};
inline utils::StringStream& operator<<(utils::StringStream& out, Token::Type type) {
out << Token::TypeToName(type);
return out;
}
} // namespace tint::reader::wgsl
#endif // SRC_TINT_READER_WGSL_TOKEN_H_