From 7cbb7da80bfe63a138a2e690110306317a8e8b0d Mon Sep 17 00:00:00 2001
From: TomyLobo <tomylobo@nurfuerspam.de>
Date: Thu, 24 Nov 2011 19:44:15 +0100
Subject: [PATCH] Added the ternary operator.

---
 .../worldedit/expression/lexer/Lexer.java     |  2 +
 .../expression/parser/ParserProcessors.java   | 57 ++++++++++++++++++-
 .../expression/runtime/Conditional.java       |  4 +-
 3 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/src/main/java/com/sk89q/worldedit/expression/lexer/Lexer.java b/src/main/java/com/sk89q/worldedit/expression/lexer/Lexer.java
index 21a6b163d..007ec5eb2 100644
--- a/src/main/java/com/sk89q/worldedit/expression/lexer/Lexer.java
+++ b/src/main/java/com/sk89q/worldedit/expression/lexer/Lexer.java
@@ -105,6 +105,8 @@ public class Lexer {
         characterTokens.add('{');
         characterTokens.add('}');
         characterTokens.add(';');
+        characterTokens.add('?');
+        characterTokens.add(':');
     }
 
     private static final Set<String> keywords = new HashSet<String>(Arrays.asList("if", "else", "while", "do", "for", "break", "continue", "return"));
diff --git a/src/main/java/com/sk89q/worldedit/expression/parser/ParserProcessors.java b/src/main/java/com/sk89q/worldedit/expression/parser/ParserProcessors.java
index 74d535265..d4f4c5ba2 100644
--- a/src/main/java/com/sk89q/worldedit/expression/parser/ParserProcessors.java
+++ b/src/main/java/com/sk89q/worldedit/expression/parser/ParserProcessors.java
@@ -28,6 +28,7 @@ import java.util.Map;
 import com.sk89q.worldedit.expression.Identifiable;
 import com.sk89q.worldedit.expression.lexer.tokens.OperatorToken;
 import com.sk89q.worldedit.expression.lexer.tokens.Token;
+import com.sk89q.worldedit.expression.runtime.Conditional;
 import com.sk89q.worldedit.expression.runtime.RValue;
 import com.sk89q.worldedit.expression.runtime.Operators;
 
@@ -235,7 +236,61 @@ public final class ParserProcessors {
     }
 
     private static RValue processTernaryOps(LinkedList<Identifiable> input) throws ParserException {
-        return processBinaryOpsLA(input, binaryOpMapsLA.length - 1);
+        LinkedList<Identifiable> lhs = new LinkedList<Identifiable>();
+        LinkedList<Identifiable> mhs = new LinkedList<Identifiable>();
+        LinkedList<Identifiable> rhs = new LinkedList<Identifiable>();
+
+        int partsFound = 0;
+        int conditionalsFound = 0;
+
+        for (Identifiable identifiable : input) {
+            final char character = identifiable.id();
+            switch (character) {
+            case '?':
+                ++conditionalsFound;
+                break;
+            case ':':
+                --conditionalsFound;
+                break;
+            }
+
+            if (conditionalsFound < 0) {
+                throw new ParserException(identifiable.getPosition(), "Unexpected ':'");
+            }
+
+            switch (partsFound) {
+            case 0:
+                if (character == '?') {
+                    System.out.println("question mark found");
+                    partsFound = 1;
+                } else {
+                    lhs.addLast(identifiable);
+                }
+                break;
+
+            case 1:
+                if (conditionalsFound == 0 && character == ':') {
+                    System.out.println("matching colon found");
+                    partsFound = 2;
+                } else {
+                    mhs.addLast(identifiable);
+                }
+                break;
+
+            case 2:
+                rhs.addLast(identifiable);
+            }
+        }
+
+        if (partsFound < 2) {
+            return processBinaryOpsLA(input, binaryOpMapsLA.length - 1);
+        }
+
+        RValue lhsInvokable = processBinaryOpsLA(lhs, binaryOpMapsLA.length - 1);
+        RValue mhsInvokable = processTernaryOps(mhs);
+        RValue rhsInvokable = processTernaryOps(rhs);
+
+        return new Conditional(input.get(lhs.size()).getPosition(), lhsInvokable, mhsInvokable, rhsInvokable);
     }
 
     private static RValue processUnaryOps(LinkedList<Identifiable> input) throws ParserException {
diff --git a/src/main/java/com/sk89q/worldedit/expression/runtime/Conditional.java b/src/main/java/com/sk89q/worldedit/expression/runtime/Conditional.java
index b7a5a02c5..c6c7d1c7c 100644
--- a/src/main/java/com/sk89q/worldedit/expression/runtime/Conditional.java
+++ b/src/main/java/com/sk89q/worldedit/expression/runtime/Conditional.java
@@ -55,8 +55,10 @@ public class Conditional extends Node {
     public String toString() {
         if (falsePart == null) {
             return "if (" + condition + ") { " + truePart + " }";
-        } else {
+        } else if (truePart instanceof Sequence || falsePart instanceof Sequence) {
             return "if (" + condition + ") { " + truePart + " } else { " + falsePart + " }";
+        } else {
+            return "(" + condition + ") ? (" + truePart + ") : (" + falsePart + ")";
         }
     }