src/main/java/org/zwobble/couscous/backends/python/PythonSerializer.java


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
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

package org.zwobble.couscous.backends.python;

import org.zwobble.couscous.backends.python.ast.PythonBlock;
import org.zwobble.couscous.backends.python.ast.PythonBooleanLiteralNode;
import org.zwobble.couscous.backends.python.ast.PythonClassNode;
import org.zwobble.couscous.backends.python.ast.PythonFunctionDefinitionNode;
import org.zwobble.couscous.backends.python.ast.PythonIntegerLiteralNode;
import org.zwobble.couscous.backends.python.ast.PythonModuleNode;
import org.zwobble.couscous.backends.python.ast.PythonNode;
import org.zwobble.couscous.backends.python.ast.PythonPassNode;
import org.zwobble.couscous.backends.python.ast.PythonReturnNode;
import org.zwobble.couscous.backends.python.ast.PythonStringLiteralNode;
import org.zwobble.couscous.backends.python.ast.PythonVariableReferenceNode;
import org.zwobble.couscous.backends.python.ast.PythonWriter;
import org.zwobble.couscous.backends.python.ast.visitors.PythonNodeVisitor;

import static com.google.common.collect.Iterables.skip;

import lombok.val;

public class PythonSerializer implements PythonNodeVisitor<Void> {
    public static String serialize(PythonNode node) {
        val writer = new PythonWriter();
        val serializer = new PythonSerializer(writer);
        serializer.write(node);
        return writer.asString();
    }
    
    private PythonWriter writer;
    
    private PythonSerializer(PythonWriter writer) {
        this.writer = writer;
    }
    
    public void write(PythonNode node) {
        node.accept(this);
    }
    
    @Override
    public Void visit(PythonIntegerLiteralNode integerLiteral) {
        writer.writeInteger(integerLiteral.getValue());
        return null;
    }

    @Override
    public Void visit(PythonStringLiteralNode stringLiteral) {
        writer.writeStringLiteral(stringLiteral.getValue());
        return null;
    }

    @Override
    public Void visit(PythonBooleanLiteralNode booleanLiteral) {
        writer.writeKeyword(booleanLiteral.getValue() ? "True" : "False");
        return null;
    }

    @Override
    public Void visit(PythonVariableReferenceNode reference) {
        writer.writeIdentifier(reference.getName());
        return null;
    }

    @Override
    public Void visit(PythonReturnNode pythonReturn) {
        writer.startStatement();
        writer.writeKeyword("return");
        writer.writeSpace();
        write(pythonReturn.getValue());
        writer.endStatement();
        return null;
    }

    @Override
    public Void visit(PythonPassNode pass) {
        writer.startStatement();
        writer.writeKeyword("pass");
        writer.endStatement();
        return null;
    }

    @Override
    public Void visit(PythonClassNode pythonClass) {
        writer.startStatement();
        writer.writeKeyword("class");
        writer.writeSpace();
        writer.writeIdentifier(pythonClass.getName());
        writer.writeSymbol("(");
        writer.writeIdentifier("object");
        writer.writeSymbol(")");
        writeBlock(pythonClass.getBody());
        writer.endStatement();
        return null;
    }

    @Override
    public Void visit(PythonFunctionDefinitionNode functionDefinition) {
        writer.startStatement();
        writer.writeKeyword("def");
        writer.writeSpace();
        writer.writeIdentifier(functionDefinition.getName());
        writer.writeSymbol("(");
        writeArgumentNames(functionDefinition);
        writer.writeSymbol(")");
        writeBlock(functionDefinition.getBody());
        writer.endStatement();
        return null;
    }

    private void writeArgumentNames(PythonFunctionDefinitionNode functionDefinition) {
        if (!functionDefinition.getArgumentNames().isEmpty()) {
            writer.writeIdentifier(functionDefinition.getArgumentNames().get(0));
            for (val argumentName : skip(functionDefinition.getArgumentNames(), 1)) {
                writer.writeSymbol(",");
                writer.writeSpace();
                writer.writeIdentifier(argumentName);
            }
        }
    }

    @Override
    public Void visit(PythonModuleNode module) {
        for (val statement : module.getStatements()) {
            write(statement);
        }
        return null;
    }

    private void writeBlock(PythonBlock body) {
        writer.startBlock();
        for (val statement : body) {
            write(statement);
        }
        writer.endBlock();
    }
}