Move the JSON parser from evalengine

go/vt/sqlparser/parse_date.go → go/mysql/datetime/parse.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package sqlparser
+package datetime
 
 import (
 	"fmt"

go/vt/sqlparser/parse_date_test.go → go/mysql/datetime/parse_test.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package sqlparser
+package datetime
 
 import (
 	"testing"

go/mysql/float.go

@@ -0,0 +1,50 @@
+/*
+Copyright 2023 The Vitess 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.
+*/
+
+package mysql
+
+import (
+	"bytes"
+	"strconv"
+
+	"vitess.io/vitess/go/sqltypes"
+)
+
+// FormatFloat formats a float64 as a byte string in a similar way to what MySQL does
+func FormatFloat(typ sqltypes.Type, f float64) []byte {
+	return AppendFloat(nil, typ, f)
+}
+
+func AppendFloat(buf []byte, typ sqltypes.Type, f float64) []byte {
+	format := byte('g')
+	if typ == sqltypes.Decimal {
+		format = 'f'
+	}
+
+	// the float printer in MySQL does not add a positive sign before
+	// the exponent for positive exponents, but the Golang printer does
+	// do that, and there's no way to customize it, so we must strip the
+	// redundant positive sign manually
+	// e.g. 1.234E+56789 -> 1.234E56789
+	fstr := strconv.AppendFloat(buf, f, format, -1, 64)
+	if idx := bytes.IndexByte(fstr, 'e'); idx >= 0 {
+		if fstr[idx+1] == '+' {
+			fstr = append(fstr[:idx+1], fstr[idx+2:]...)
+		}
+	}
+
+	return fstr
+}