hunt.sql.visitor.functions.Insert 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.Insert;
17 
18 // import hunt.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
19 
20 import hunt.sql.ast.SQLExpr;
21 import hunt.sql.ast.expr.SQLMethodInvokeExpr;
22 import hunt.sql.visitor.SQLEvalVisitor;
23 import hunt.sql.visitor.functions.Function;
24 import hunt.Number;
25 import hunt.String;
26 import hunt.String;
27 import hunt.collection;
28 import std.conv;
29 import std.uni;
30 import hunt.text;
31 
32 import std.concurrency : initOnce;
33 
34 public class Insert : Function {
35 
36     static Insert instance() {
37         __gshared Insert inst;
38         return initOnce!inst(new Insert());
39     }    
40 
41     // public  static Insert instance;
42     // static this()
43     // {
44     //     instance = new Insert();
45     // }
46 
47     public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
48         if (x.getParameters().size() != 4) {
49             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
50         }
51 
52         SQLExpr param0 = x.getParameters().get(0);
53         SQLExpr param1 = x.getParameters().get(1);
54         SQLExpr param2 = x.getParameters().get(2);
55         SQLExpr param3 = x.getParameters().get(3);
56         param0.accept(visitor);
57         param1.accept(visitor);
58         param2.accept(visitor);
59         param3.accept(visitor);
60 
61         Object param0Value = param0.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
62         Object param1Value = param1.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
63         Object param2Value = param2.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
64         Object param3Value = param3.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
65 
66         if (!(cast(String)(param0Value) !is null)) {
67             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
68         }
69         if (!(cast(Number)(param1Value) !is null)) {
70             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
71         }
72         if (!(cast(Number)(param2Value) !is null)) {
73             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
74         }
75         if (!(cast(String)(param3Value) !is null)) {
76             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
77         }
78 
79         string str = (cast(String) param0Value).value();
80         int pos = (cast(Number) param1Value).intValue();
81         int len = (cast(Number) param2Value).intValue();
82         string newstr = (cast(String) param3Value).value();
83         
84         if (pos <= 0) {
85             return new String(str);
86         }
87         
88         if (pos == 1) {
89             if (len > str.length) {
90                 return new String(newstr);
91             }
92             return new String(newstr ~ str.substring(len));
93         }
94         
95         string first = str.substring(0, pos - 1);
96         if (pos + len - 1 > str.length) {
97             return new String(first ~ newstr);
98         }
99         
100         return new String(first ~ newstr ~ str.substring(pos + len - 1));
101     }
102 }