remove dependency on TiDB (#679)

Author: tangenta

README.md

@@ -7,6 +7,33 @@ TiDB SQL Parser
 
 ## How to use it
 
+```go
+import (
+	"fmt"
+	"github.com/pingcap/parser"
+	_ "github.com/pingcap/tidb/types/parser_driver"
+)
+
+// This example show how to parse a text sql into ast.
+func example() {
+
+	// 0. make sure import parser_driver implemented by TiDB(user also can implement own driver by self).
+	// and add `import _ "github.com/pingcap/tidb/types/parser_driver"` in the head of file.
+
+	// 1. Create a parser. The parser is NOT goroutine safe and should
+	// not be shared among multiple goroutines. However, parser is also
+	// heavy, so each goroutine should reuse its own local instance if
+	// possible.
+	p := parser.New()
+
+	// 2. Parse a text SQL into AST([]ast.StmtNode).
+	stmtNodes, _, err := p.Parse("select * from tbl where id = 1", "", "")
+
+	// 3. Use AST to do cool things.
+	fmt.Println(stmtNodes[0], err)
+}
+```
+
 See [https://godoc.org/github.com/pingcap/parser](https://godoc.org/github.com/pingcap/parser)
 
 ## How to update parser for TiDB

ast/expressions_test.go

@@ -17,7 +17,6 @@ import (
 	. "github.com/pingcap/check"
 	. "github.com/pingcap/parser/ast"
 	"github.com/pingcap/parser/format"
-	_ "github.com/pingcap/tidb/types/parser_driver"
 )
 
 var _ = Suite(&testExpressionsSuite{})

ast/functions_test.go

@@ -16,9 +16,8 @@ package ast_test
 import (
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser"
-	"github.com/pingcap/parser/ast"
 	. "github.com/pingcap/parser/ast"
-	driver "github.com/pingcap/tidb/types/parser_driver"
+	"github.com/pingcap/parser/test_driver"
 )
 
 var _ = Suite(&testFunctionsSuite{})
@@ -146,9 +145,9 @@ func (ts *testFunctionsSuite) TestConvert(c *C) {
 		}
 		c.Assert(err, IsNil)
 
-		st := stmt.(*ast.SelectStmt)
+		st := stmt.(*SelectStmt)
 		expr := st.Fields.Fields[0].Expr.(*FuncCallExpr)
-		charsetArg := expr.Args[1].(*driver.ValueExpr)
+		charsetArg := expr.Args[1].(*test_driver.ValueExpr)
 		c.Assert(charsetArg.GetString(), Equals, testCase.CharsetName)
 	}
 }
@@ -175,9 +174,9 @@ func (ts *testFunctionsSuite) TestChar(c *C) {
 		}
 		c.Assert(err, IsNil)
 
-		st := stmt.(*ast.SelectStmt)
+		st := stmt.(*SelectStmt)
 		expr := st.Fields.Fields[0].Expr.(*FuncCallExpr)
-		charsetArg := expr.Args[1].(*driver.ValueExpr)
+		charsetArg := expr.Args[1].(*test_driver.ValueExpr)
 		c.Assert(charsetArg.GetString(), Equals, testCase.CharsetName)
 	}
 }

ast/util_test.go

@@ -21,7 +21,7 @@ import (
 	"github.com/pingcap/parser"
 	. "github.com/pingcap/parser/ast"
 	. "github.com/pingcap/parser/format"
-	"github.com/pingcap/tidb/types/parser_driver"
+	"github.com/pingcap/parser/test_driver"
 )
 
 var _ = Suite(&testCacheableSuite{})
@@ -99,7 +99,7 @@ func (checker *nodeTextCleaner) Enter(in Node) (out Node, skipChildren bool) {
 		node.FnName.O = strings.ToLower(node.FnName.O)
 		switch node.FnName.L {
 		case "convert":
-			node.Args[1].(*driver.ValueExpr).Datum.SetBytes(nil)
+			node.Args[1].(*test_driver.ValueExpr).Datum.SetBytes(nil)
 		}
 	case *AggregateFuncExpr:
 		node.F = strings.ToLower(node.F)

go.mod1

@@ -7,13 +7,14 @@ require (
 	github.com/cznic/sortutil v0.0.0-20181122101858-f5f958428db8
 	github.com/cznic/strutil v0.0.0-20171016134553-529a34b1c186
 	github.com/cznic/y v0.0.0-20170802143616-045f81c6662a
+	github.com/golang/protobuf v1.3.2 // indirect
 	github.com/pingcap/check v0.0.0-20190102082844-67f458068fc8
 	github.com/pingcap/errors v0.11.4
-	github.com/pingcap/tidb v0.0.0-20190703092821-755875aacb5a
 	github.com/pingcap/tipb v0.0.0-20190428032612-535e1abaa330
+	github.com/pkg/errors v0.8.1 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20190728182440-6a916e37a237 // indirect
 	github.com/sirupsen/logrus v1.3.0
 	golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2
-	gopkg.in/stretchr/testify.v1 v1.2.2 // indirect
 )
 
 go 1.13

go.sum1

@@ -29,8 +29,7 @@ import (
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
-	"github.com/pingcap/tidb/types"
-	driver "github.com/pingcap/tidb/types/parser_driver"
+	"github.com/pingcap/parser/test_driver"
 )
 
 func TestT(t *testing.T) {
@@ -251,16 +250,16 @@ func (s *testParserSuite) TestSimple(c *C) {
 	sel, ok := st.(*ast.SelectStmt)
 	c.Assert(ok, IsTrue)
 	expr := sel.Fields.Fields[0]
-	vExpr := expr.Expr.(*driver.ValueExpr)
-	c.Assert(vExpr.Kind(), Equals, types.KindInt64)
+	vExpr := expr.Expr.(*test_driver.ValueExpr)
+	c.Assert(vExpr.Kind(), Equals, test_driver.KindInt64)
 	src = "SELECT 9223372036854775808;"
 	st, err = parser.ParseOneStmt(src, "", "")
 	c.Assert(err, IsNil)
 	sel, ok = st.(*ast.SelectStmt)
 	c.Assert(ok, IsTrue)
 	expr = sel.Fields.Fields[0]
-	vExpr = expr.Expr.(*driver.ValueExpr)
-	c.Assert(vExpr.Kind(), Equals, types.KindUint64)
+	vExpr = expr.Expr.(*test_driver.ValueExpr)
+	c.Assert(vExpr.Kind(), Equals, test_driver.KindUint64)
 }
 
 func (s *testParserSuite) TestSpecialComments(c *C) {
@@ -4827,8 +4826,8 @@ func (checker *nodeTextCleaner) Enter(in ast.Node) (out ast.Node, skipChildren b
 		node.F = strings.ToLower(node.F)
 	case *ast.SelectField:
 		node.Offset = 0
-	case *driver.ValueExpr:
-		if node.Kind() == types.KindMysqlDecimal {
+	case *test_driver.ValueExpr:
+		if node.Kind() == test_driver.KindMysqlDecimal {
 			node.GetMysqlDecimal().FromString(node.GetMysqlDecimal().ToString())
 		}
 	case *ast.GrantStmt: