/
Productions.java
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/
Productions.java
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package org.isk.jvmhardcore.mathparser;
import java.util.Stack;
import org.isk.jvmhardcore.mathparser.core.Production;
public class Productions {
// stream = expression eof
public static class Stream implements Production<EventType, MathTokenizer> {
public EventType produce(MathTokenizer tokenizer,
Production<EventType, MathTokenizer>[] table,
Stack<Production<EventType, MathTokenizer>> productionStack) {
productionStack.push(table[Symbols.EOF]);
productionStack.push(table[Symbols.EXPRESSION]);
return null;
}
}
// expression = ws number ws operator ws number ws
public static class Expression implements Production<EventType, MathTokenizer> {
public EventType produce(MathTokenizer tokenizer,
Production<EventType, MathTokenizer>[] table,
Stack<Production<EventType, MathTokenizer>> productionStack) {
productionStack.push(table[Symbols.WS]);
productionStack.push(table[Symbols.NUMBER]);
productionStack.push(table[Symbols.WS]);
productionStack.push(table[Symbols.OPERATOR]);
productionStack.push(table[Symbols.WS]);
productionStack.push(table[Symbols.NUMBER]);
productionStack.push(table[Symbols.WS]);
return null;
}
}
// number = integer | float
// integer = repeatingDigit
// float = oRepeatingDigit [dot] oRepeatingDigit
// repeatingDigit = digit oRepeatingDigit
// oRepeatingDigit = {digit}
// sign = '+' | '-' | ''
// digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
// dot = '.'
public static class Number implements Production<EventType, MathTokenizer> {
public EventType produce(MathTokenizer tokenizer,
Production<EventType, MathTokenizer>[] table,
Stack<Production<EventType, MathTokenizer>> productionStack) {
if (tokenizer.isFloat()) {
return EventType.FLOAT;
} else {
return EventType.INTEGER;
}
}
}
// operator = '+' | '-' | '/' | '*'
public static class Operator implements Production<EventType, MathTokenizer> {
public EventType produce(MathTokenizer tokenizer,
Production<EventType, MathTokenizer>[] table,
Stack<Production<EventType, MathTokenizer>> productionStack) {
return EventType.OPERATOR;
}
}
// ws = ? whitespaces ?
public static class Whitespaces implements Production<EventType, MathTokenizer> {
public EventType produce(MathTokenizer tokenizer,
Production<EventType, MathTokenizer>[] table,
Stack<Production<EventType, MathTokenizer>> productionStack) {
tokenizer.consumeUnprintables();
return null;
}
}
// eof = ? end of stream ?
public static class EndOfFile implements Production<EventType, MathTokenizer> {
public EventType produce(MathTokenizer tokenizer,
Production<EventType, MathTokenizer>[] table,
Stack<Production<EventType, MathTokenizer>> productionStack) {
return EventType.EOF;
}
}
}