1 files changed, 241 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/syntax/tokens.go b/src/cmd/compile/internal/syntax/tokens.go
new file mode 100644
index 0000000000..9243f1e14f
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/tokens.go
@@ -0,0 +1,241 @@
+// 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
+)
+
+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 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
+)