forked from golang/go
/
tokens.go
263 lines (227 loc) · 3.55 KB
/
tokens.go
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package syntax
import "fmt"
type token uint
const (
_ token = iota
_EOF
// names and literals
_Name
_Literal
// operators and operations
_Operator // excluding '*' (_Star)
_AssignOp
_IncOp
_Assign
_Define
_Arrow
_Star
// delimitors
_Lparen
_Lbrack
_Lbrace
_Rparen
_Rbrack
_Rbrace
_Comma
_Semi
_Colon
_Dot
_DotDotDot
// keywords
_Break
_Case
_Chan
_Const
_Continue
_Default
_Defer
_Else
_Fallthrough
_For
_Func
_Go
_Goto
_If
_Import
_Interface
_Map
_Package
_Range
_Return
_Select
_Struct
_Switch
_Type
_Var
tokenCount
)
const (
// for BranchStmt
Break = _Break
Continue = _Continue
Fallthrough = _Fallthrough
Goto = _Goto
// for CallStmt
Go = _Go
Defer = _Defer
)
var tokstrings = [...]string{
// source control
_EOF: "EOF",
// names and literals
_Name: "name",
_Literal: "literal",
// operators and operations
_Operator: "op",
_AssignOp: "op=",
_IncOp: "opop",
_Assign: "=",
_Define: ":=",
_Arrow: "<-",
_Star: "*",
// delimitors
_Lparen: "(",
_Lbrack: "[",
_Lbrace: "{",
_Rparen: ")",
_Rbrack: "]",
_Rbrace: "}",
_Comma: ",",
_Semi: ";",
_Colon: ":",
_Dot: ".",
_DotDotDot: "...",
// keywords
_Break: "break",
_Case: "case",
_Chan: "chan",
_Const: "const",
_Continue: "continue",
_Default: "default",
_Defer: "defer",
_Else: "else",
_Fallthrough: "fallthrough",
_For: "for",
_Func: "func",
_Go: "go",
_Goto: "goto",
_If: "if",
_Import: "import",
_Interface: "interface",
_Map: "map",
_Package: "package",
_Range: "range",
_Return: "return",
_Select: "select",
_Struct: "struct",
_Switch: "switch",
_Type: "type",
_Var: "var",
}
func (tok token) String() string {
var s string
if 0 <= tok && int(tok) < len(tokstrings) {
s = tokstrings[tok]
}
if s == "" {
s = fmt.Sprintf("<tok-%d>", tok)
}
return s
}
// Make sure we have at most 64 tokens so we can use them in a set.
const _ uint64 = 1 << (tokenCount - 1)
// contains reports whether tok is in tokset.
func contains(tokset uint64, tok token) bool {
return tokset&(1<<tok) != 0
}
type LitKind uint
const (
IntLit LitKind = iota
FloatLit
ImagLit
RuneLit
StringLit
)
type Operator uint
const (
_ Operator = iota
Def // :=
Not // !
Recv // <-
// precOrOr
OrOr // ||
// precAndAnd
AndAnd // &&
// precCmp
Eql // ==
Neq // !=
Lss // <
Leq // <=
Gtr // >
Geq // >=
// precAdd
Add // +
Sub // -
Or // |
Xor // ^
// precMul
Mul // *
Div // /
Rem // %
And // &
AndNot // &^
Shl // <<
Shr // >>
)
var opstrings = [...]string{
// prec == 0
Def: ":", // : in :=
Not: "!",
Recv: "<-",
// precOrOr
OrOr: "||",
// precAndAnd
AndAnd: "&&",
// precCmp
Eql: "==",
Neq: "!=",
Lss: "<",
Leq: "<=",
Gtr: ">",
Geq: ">=",
// precAdd
Add: "+",
Sub: "-",
Or: "|",
Xor: "^",
// precMul
Mul: "*",
Div: "/",
Rem: "%",
And: "&",
AndNot: "&^",
Shl: "<<",
Shr: ">>",
}
func (op Operator) String() string {
var s string
if 0 <= op && int(op) < len(opstrings) {
s = opstrings[op]
}
if s == "" {
s = fmt.Sprintf("<op-%d>", op)
}
return s
}
// Operator precedences
const (
_ = iota
precOrOr
precAndAnd
precCmp
precAdd
precMul
)