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
136
137
138
139
140
141
142
143
144
|
package bjc.dicelang.ast;
import java.util.Deque;
import java.util.LinkedList;
import java.util.function.Function;
import org.apache.commons.lang3.StringUtils;
import bjc.dicelang.ast.nodes.IDiceASTNode;
import bjc.dicelang.ast.nodes.LiteralDiceNode;
import bjc.dicelang.ast.nodes.OperatorDiceNode;
import bjc.dicelang.ast.nodes.VariableDiceNode;
import bjc.utils.data.Pair;
import bjc.utils.funcdata.FunctionalList;
import bjc.utils.funcdata.FunctionalStringTokenizer;
import bjc.utils.funcutils.ListUtils;
import bjc.utils.parserutils.AST;
import bjc.utils.parserutils.ShuntingYard;
import bjc.utils.parserutils.TreeConstructor;
/**
* Create an AST from a string expression
*
* @author ben
*
*/
public class DiceASTParser {
private static final class NodeBaker
implements Function<String, IDiceASTNode> {
@Override
public IDiceASTNode apply(String tok) {
if (isOperator(tok)) {
return OperatorDiceNode.fromString(tok);
} else if (NodeBaker.isLiteral(tok)) {
return new LiteralDiceNode(tok);
} else {
return new VariableDiceNode(tok);
}
}
/**
* Check if a token represents a literal
*
* @param tok
* The token to check
* @return Whether or not the token represents a literal
*/
private static boolean isLiteral(String tok) {
if (StringUtils.countMatches(tok, 'c') == 1
&& !tok.equalsIgnoreCase("c")) {
return true;
} else if (StringUtils.countMatches(tok, 'd') == 1
&& !tok.equalsIgnoreCase("d")) {
return true;
} else {
try {
Integer.parseInt(tok);
return true;
} catch (NumberFormatException nfx) {
return false;
}
}
}
}
/**
* The yard to use for shunting expressions
*/
private static ShuntingYard<String> yard;
static {
yard = new ShuntingYard<>();
yard.addOp("d", 5); // dice operator: use for creating variable
// size dice groups
yard.addOp("c", 6); // compound operator: use for creating compound
// dice from expressions
yard.addOp(":=", 0); // binding operator: Bind a name to a variable
// expression
}
/**
* Build an AST from a string expression
*
* @param exp
* The string to build from
* @return An AST built from the passed in string
*/
public AST<IDiceASTNode> buildAST(String exp) {
FunctionalList<String> tokens =
FunctionalStringTokenizer.fromString(exp).toList();
Deque<Pair<String, String>> ops = new LinkedList<>();
ops.add(new Pair<>("+", "\\+"));
ops.add(new Pair<>("-", "-"));
ops.add(new Pair<>("*", "\\*"));
ops.add(new Pair<>("/", "/"));
ops.add(new Pair<>(":=", ":="));
FunctionalList<String> semiExpandedTokens =
ListUtils.splitTokens(tokens, ops);
ops = new LinkedList<>();
ops.add(new Pair<>("(", "\\("));
ops.add(new Pair<>(")", "\\)"));
FunctionalList<String> fullyExpandedTokens =
ListUtils.deAffixTokens(semiExpandedTokens, ops);
FunctionalList<String> shunted =
yard.postfix(fullyExpandedTokens, (s) -> s);
AST<String> rawAST = TreeConstructor.constructTree(shunted,
DiceASTParser::isOperator);
AST<IDiceASTNode> bakedAST = rawAST.transmuteAST(new NodeBaker());
return bakedAST;
}
/**
* Check if a token represents an operator
*
* @param tok
* The token to check if it represents an operator
* @return Whether or not the token represents an operator
*/
private static boolean isOperator(String tok) {
switch (tok) {
case ":=":
case "+":
case "-":
case "*":
case "/":
case "c":
case "d":
return true;
default:
return false;
}
}
}
|
