-
Notifications
You must be signed in to change notification settings - Fork 0
/
split.go
executable file
·111 lines (90 loc) · 2.72 KB
/
split.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
// Copyright 2020-2021 Dolthub, Inc.
//
// 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 function
import (
"fmt"
"regexp"
"github.com/Rock-liyi/p2pdb-store/sql"
"github.com/Rock-liyi/p2pdb-store/sql/expression"
)
// Split receives a string and returns the parts of it splitted by a
// delimiter.
type Split struct {
expression.BinaryExpression
}
var _ sql.FunctionExpression = (*Split)(nil)
// NewSplit creates a new Split UDF.
func NewSplit(str, delimiter sql.Expression) sql.Expression {
return &Split{expression.BinaryExpression{
Left: str,
Right: delimiter,
}}
}
// FunctionName implements sql.FunctionExpression
func (f *Split) FunctionName() string {
return "split"
}
// Description implements sql.FunctionExpression
func (f *Split) Description() string {
return "returns the parts of the string str split by the separator sep as a JSON array of strings."
}
// Eval implements the Expression interface.
func (f *Split) Eval(ctx *sql.Context, row sql.Row) (interface{}, error) {
left, err := f.Left.Eval(ctx, row)
if err != nil {
return nil, err
}
if left == nil {
return nil, nil
}
left, err = sql.LongText.Convert(left)
if err != nil {
return nil, err
}
right, err := f.Right.Eval(ctx, row)
if err != nil {
return nil, err
}
if right == nil {
return nil, nil
}
right, err = sql.LongText.Convert(right)
if err != nil {
return nil, err
}
re, err := regexp.Compile(right.(string))
if err != nil {
return nil, err
}
parts := re.Split(left.(string), -1)
var result = make([]interface{}, len(parts))
for i, part := range parts {
result[i] = part
}
return result, nil
}
// Type implements the Expression interface.
func (*Split) Type() sql.Type { return sql.CreateArray(sql.LongText) }
// IsNullable implements the Expression interface.
func (f *Split) IsNullable() bool { return f.Left.IsNullable() || f.Right.IsNullable() }
func (f *Split) String() string {
return fmt.Sprintf("split(%s, %s)", f.Left, f.Right)
}
// WithChildren implements the Expression interface.
func (f *Split) WithChildren(children ...sql.Expression) (sql.Expression, error) {
if len(children) != 2 {
return nil, sql.ErrInvalidChildrenNumber.New(f, len(children), 2)
}
return NewSplit(children[0], children[1]), nil
}