hunt.sql.visitor.functions.Locate source code

1 /*
2  * Copyright 2015-2018 HuntLabs.cn
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 module hunt.sql.visitor.functions.Locate;
17 
18 // import hunt.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
19 
20 import hunt.Integer;
21 import hunt.Number;
22 
23 import hunt.String;
24 import hunt.String;
25 import hunt.collection;
26 import std.conv;
27 import std.uni;
28 import std.string;
29 import hunt.sql.ast.SQLExpr;
30 import hunt.sql.ast.expr.SQLMethodInvokeExpr;
31 import hunt.sql.visitor.SQLEvalVisitor;
32 import hunt.sql.visitor.functions.Function;
33 
34 import std.concurrency : initOnce;
35 
36 public class Locate : Function {
37 
38     static Locate instance() {
39         __gshared Locate inst;
40         return initOnce!inst(new Locate());
41     } 
42 
43     // public  static Locate instance;
44 
45     // static this()
46     // {
47     //     instance = new Locate();
48     // }
49 
50     public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
51         List!(SQLExpr) params = x.getParameters();
52         int paramSize = params.size();
53         if (paramSize != 2 && paramSize != 3) {
54             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
55         }
56 
57         SQLExpr param0 = params.get(0);
58         SQLExpr param1 = params.get(1);
59         SQLExpr param2 = null;
60 
61         param0.accept(visitor);
62         param1.accept(visitor);
63         if (paramSize == 3) {
64             param2 = params.get(2);
65             param2.accept(visitor);
66         }
67 
68         Object param0Value = param0.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
69         Object param1Value = param1.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
70         if (param0Value is null || param1Value is null) {
71             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
72         }
73 
74         string strValue0 = param0Value.toString();
75         string strValue1 = param1Value.toString();
76 
77         if (paramSize == 2) {
78             int result = cast(int)(strValue1.indexOf(strValue0) + 1);
79             return new Integer(result);
80         }
81         
82         Object param2Value = param2.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
83         int start = (cast(Number) param2Value).intValue();
84         
85         int result = cast(int)(strValue1.indexOf(strValue0, start + 1) + 1);
86         return new Integer(result);
87     }
88 }