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package bjc.dicelang.v2;
import bjc.utils.funcdata.FunctionalList;
import bjc.utils.funcdata.FunctionalMap;
import bjc.utils.funcdata.IList;
import bjc.utils.funcdata.IMap;
import java.util.Deque;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;
import static bjc.dicelang.v2.Token.Type.*;
public class Shunter {
// The binary operators and their
// priorities
private IMap<Token.Type, Integer> ops;
// Unary operators that can only be
// applied to non-operator tokens
private Set<Token.Type> unaryAdjectives;
// Unary operators that con only be
// applied to operator tokens
private Set<Token.Type> unaryAdverbs;
private final int MATH_PREC = 20;
private final int DICE_PREC = 10;
private final int EXPR_PREC = 0;
public Shunter() {
ops = new FunctionalMap<>();
unaryAdjectives = new HashSet<>();
unaryAdverbs = new HashSet<>();
ops.put(ADD, 0 + MATH_PREC);
ops.put(SUBTRACT, 0 + MATH_PREC);
ops.put(MULTIPLY, 1 + MATH_PREC);
ops.put(IDIVIDE, 1 + MATH_PREC);
ops.put(DIVIDE, 1 + MATH_PREC);
ops.put(DICEGROUP, 0 + DICE_PREC);
ops.put(DICECONCAT, 1 + DICE_PREC);
ops.put(DICELIST, 2 + DICE_PREC);
ops.put(LET, 0 + EXPR_PREC);
ops.put(BIND, 1 + EXPR_PREC);
}
public boolean shuntTokens(IList<Token> tks, IList<Token> returned) {
Deque<Token> opStack = new LinkedList<>();
boolean unaryMode = false;
Deque<Token> unaryOps = new LinkedList<>();
for(Token tk : tks.toIterable()) {
if(unaryMode) {
// @TODO finish unary mode
if(unaryAdjectives.contains(tk.type) || unaryAdverbs.contains(tk.type)) {
unaryOps.push(tk);
continue;
}
Token currOperator = unaryOps.peek();
if(unaryAdjectives.contains(currOperator.type)) {
boolean isOp = ops.containsKey(tk.type)
|| unaryAdverbs.contains(tk.type)
|| unaryAdjectives.contains(tk.type);
if(isOp) {
System.out.printf("\tError: Unary operator %s is an"
+ " adjective, not an adverb (can't be applied"
+ " to operator %s)\n", currOperator, tk );
return false;
}
returned.add(tk);
returned.add(unaryOps.pop());
} else if (unaryAdverbs.contains(currOperator.type)) {
if(opStack.size() < 1) {
System.out.printf("\tError: Unary operators %s is an adverb,"
+ " but there is no operator to apply it to\n");
}
Token currOperand = opStack.peek();
boolean isOp = ops.containsKey(currOperand.type)
|| unaryAdverbs.contains(currOperand.type)
|| unaryAdjectives.contains(currOperand.type);
if(!isOp) {
System.out.printf("\tError: Unary operator %s is an adverb,"
+ " not an adjective (can't be applied to operand %s)\n",
currOperator, tk);
return false;
}
returned.add(tk);
returned.add(unaryOps.pop());
}
if(unaryOps.isEmpty()) unaryMode = false;
} else {
if(unaryAdjectives.contains(tk.type) || unaryAdverbs.contains(tk.type)) {
unaryMode = true;
unaryOps.add(tk);
continue;
} else if(ops.containsKey(tk.type)) {
while(!opStack.isEmpty()
&& isHigherPrec(tk.type, opStack.peek().type)) {
returned.add(opStack.pop());
}
opStack.push(tk);
} else if(tk.type == OPAREN) {
opStack.push(tk);
} else if(tk.type == CPAREN) {
Token currTk = opStack.peek();
while(currTk.type != OPAREN && currTk.intValue != tk.intValue) {
if(opStack.isEmpty()) {
System.out.printf("\tError: Could not find matching parenthesis"
+ " with matching level %d\n", tk.intValue);
return false;
}
returned.add(opStack.pop());
}
} else {
returned.add(tk);
}
}
}
// Flush leftover operators
while(!opStack.isEmpty()) {
returned.add(opStack.pop());
}
return true;
}
private boolean isHigherPrec(Token.Type left, Token.Type right) {
boolean exists = ops.containsKey(right);
// If it doesn't, the left is higher precedence.
if (!exists) {
return false;
}
int rightPrecedence = ops.get(right);
int leftPrecedence = ops.get(left);
return rightPrecedence >= leftPrecedence;
}
}
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