github.com/XiaoMi/Gaea@v1.2.5/parser/opcode/opcode.go (about)

     1  // Copyright 2015 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package opcode
    15  
    16  import (
    17  	"fmt"
    18  	"io"
    19  
    20  	"github.com/pingcap/errors"
    21  
    22  	"github.com/XiaoMi/Gaea/parser/format"
    23  )
    24  
    25  // Op is opcode type.
    26  type Op int
    27  
    28  // List operators.
    29  const (
    30  	LogicAnd Op = iota + 1
    31  	LeftShift
    32  	RightShift
    33  	LogicOr
    34  	GE
    35  	LE
    36  	EQ
    37  	NE
    38  	LT
    39  	GT
    40  	Plus
    41  	Minus
    42  	And
    43  	Or
    44  	Mod
    45  	Xor
    46  	Div
    47  	Mul
    48  	Not
    49  	BitNeg
    50  	IntDiv
    51  	LogicXor
    52  	NullEQ
    53  	In
    54  	Like
    55  	Case
    56  	Regexp
    57  	IsNull
    58  	IsTruth
    59  	IsFalsity
    60  )
    61  
    62  // Ops maps opcode to string.
    63  var Ops = map[Op]string{
    64  	LogicAnd:   "and",
    65  	LogicOr:    "or",
    66  	LogicXor:   "xor",
    67  	LeftShift:  "leftshift",
    68  	RightShift: "rightshift",
    69  	GE:         "ge",
    70  	LE:         "le",
    71  	EQ:         "eq",
    72  	NE:         "ne",
    73  	LT:         "lt",
    74  	GT:         "gt",
    75  	Plus:       "plus",
    76  	Minus:      "minus",
    77  	And:        "bitand",
    78  	Or:         "bitor",
    79  	Mod:        "mod",
    80  	Xor:        "bitxor",
    81  	Div:        "div",
    82  	Mul:        "mul",
    83  	Not:        "not",
    84  	BitNeg:     "bitneg",
    85  	IntDiv:     "intdiv",
    86  	NullEQ:     "nulleq",
    87  	In:         "in",
    88  	Like:       "like",
    89  	Case:       "case",
    90  	Regexp:     "regexp",
    91  	IsNull:     "isnull",
    92  	IsTruth:    "istrue",
    93  	IsFalsity:  "isfalse",
    94  }
    95  
    96  // String implements Stringer interface.
    97  func (o Op) String() string {
    98  	str, ok := Ops[o]
    99  	if !ok {
   100  		panic(fmt.Sprintf("%d", o))
   101  	}
   102  
   103  	return str
   104  }
   105  
   106  var opsLiteral = map[Op]string{
   107  	LogicAnd:   " AND ",
   108  	LogicOr:    " OR ",
   109  	LogicXor:   " XOR ",
   110  	LeftShift:  "<<",
   111  	RightShift: ">>",
   112  	GE:         ">=",
   113  	LE:         "<=",
   114  	EQ:         "=",
   115  	NE:         "!=",
   116  	LT:         "<",
   117  	GT:         ">",
   118  	Plus:       "+",
   119  	Minus:      "-",
   120  	And:        "&",
   121  	Or:         "|",
   122  	Mod:        "%",
   123  	Xor:        "^",
   124  	Div:        "/",
   125  	Mul:        "*",
   126  	Not:        "!",
   127  	BitNeg:     "~",
   128  	IntDiv:     "DIV",
   129  	NullEQ:     "<=>",
   130  	In:         "IN",
   131  	Like:       "LIKE",
   132  	Case:       "CASE",
   133  	Regexp:     "REGEXP",
   134  	IsNull:     "IS NULL",
   135  	IsTruth:    "IS TRUE",
   136  	IsFalsity:  "IS FALSE",
   137  }
   138  
   139  // Format the ExprNode into a Writer.
   140  func (o Op) Format(w io.Writer) {
   141  	fmt.Fprintf(w, "%s", opsLiteral[o])
   142  }
   143  
   144  // Restore the Op into a Writer
   145  func (o Op) Restore(ctx *format.RestoreCtx) error {
   146  	if v, ok := opsLiteral[o]; ok {
   147  		ctx.WriteKeyWord(v)
   148  		return nil
   149  	}
   150  	return errors.Errorf("Invalid opcode type %d during restoring AST to SQL text", o)
   151  }