hunt.sql.visitor.functions.Bin 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.Bin;
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.Long;
26 import hunt.String;
27 
28 import std.concurrency : initOnce;
29 
30 public class Bin : Function {
31     
32     static Bin instance() {
33         __gshared Bin inst;
34         return initOnce!inst(new Bin());
35     }    
36 
37     // public  static Bin instance;
38 
39     // static this()
40     // {
41     //     instance = new Bin();
42     // }
43 
44     public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
45         if (x.getParameters().size() != 1) {
46             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
47         }
48 
49         SQLExpr param0 = x.getParameters().get(0);
50         param0.accept(visitor);
51 
52         Object param0Value = param0.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
53         if (param0Value is null) {
54             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
55         }
56 
57         if (cast(Number)(param0Value) !is null) {
58             long longValue = (cast(Number) param0Value).longValue();
59             string result = Long.toStr(longValue, 2);
60             return new String(result);
61         }
62         return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
63     }
64 }