From c2191f4fc70462176b50a88d4ccf786b085d4294 Mon Sep 17 00:00:00 2001
From: TomyLobo <tomylobo@nurfuerspam.de>
Date: Sun, 23 Oct 2011 05:10:41 +0200
Subject: [PATCH] Generalized the Lexer a bit more and renamed a function in
 the parser.

---
 .../worldedit/expression/lexer/Lexer.java     | 76 ++++++++++---------
 .../worldedit/expression/parser/Parser.java   |  6 +-
 2 files changed, 44 insertions(+), 38 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 e7c2333ed..47ea711bb 100644
--- a/src/main/java/com/sk89q/worldedit/expression/lexer/Lexer.java
+++ b/src/main/java/com/sk89q/worldedit/expression/lexer/Lexer.java
@@ -21,8 +21,10 @@ package com.sk89q.worldedit.expression.lexer;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -74,6 +76,13 @@ public class Lexer {
             )
     );
 
+    private static final Set<Character> characterTokens = new HashSet<Character>();
+    static {
+        characterTokens.add(',');
+        characterTokens.add('(');
+        characterTokens.add(')');
+    }
+
     private static final Pattern numberPattern = Pattern.compile("^([0-9]*(?:\\.[0-9]+)?(?:[eE][+-]?[0-9]+)?)");
     private static final Pattern identifierPattern = Pattern.compile("^([A-Za-z][0-9A-Za-z_]*)");
 
@@ -93,43 +102,40 @@ public class Lexer {
             }
 
             final char ch = peek();
-            switch (ch) {
-            case ',':
-            case '(':
-            case ')':
+
+            if (characterTokens.contains(ch)) {
                 tokens.add(new CharacterToken(position++, ch));
-                break;
-
-            default:
-                final Matcher numberMatcher = numberPattern.matcher(expression.substring(position));
-                if (numberMatcher.lookingAt()) {
-                    String numberPart = numberMatcher.group(1);
-                    if (!numberPart.isEmpty()) {
-                        try {
-                            tokens.add(new NumberToken(position, Double.parseDouble(numberPart)));
-                        }
-                        catch (NumberFormatException e) {
-                            throw new LexerException(position, "Number parsing failed", e);
-                        }
-
-                        position += numberPart.length();
-                        continue;
-                    }
-                }
-
-                final Matcher identifierMatcher = identifierPattern.matcher(expression.substring(position));
-                if (identifierMatcher.lookingAt()) {
-                    String identifierPart = identifierMatcher.group(1);
-                    if (!identifierPart.isEmpty()) {
-                        tokens.add(new IdentifierToken(position, identifierPart));
-
-                        position += identifierPart.length();
-                        continue;
-                    }
-                }
-
-                throw new LexerException(position, "Unknown character '" + ch + "'");
+                continue;
             }
+
+            final Matcher numberMatcher = numberPattern.matcher(expression.substring(position));
+            if (numberMatcher.lookingAt()) {
+                String numberPart = numberMatcher.group(1);
+                if (!numberPart.isEmpty()) {
+                    try {
+                        tokens.add(new NumberToken(position, Double.parseDouble(numberPart)));
+                    }
+                    catch (NumberFormatException e) {
+                        throw new LexerException(position, "Number parsing failed", e);
+                    }
+
+                    position += numberPart.length();
+                    continue;
+                }
+            }
+
+            final Matcher identifierMatcher = identifierPattern.matcher(expression.substring(position));
+            if (identifierMatcher.lookingAt()) {
+                String identifierPart = identifierMatcher.group(1);
+                if (!identifierPart.isEmpty()) {
+                    tokens.add(new IdentifierToken(position, identifierPart));
+
+                    position += identifierPart.length();
+                    continue;
+                }
+            }
+
+            throw new LexerException(position, "Unknown character '" + ch + "'");
         }
         while (position < expression.length());
 
diff --git a/src/main/java/com/sk89q/worldedit/expression/parser/Parser.java b/src/main/java/com/sk89q/worldedit/expression/parser/Parser.java
index ab76d2490..1ad0ceefd 100644
--- a/src/main/java/com/sk89q/worldedit/expression/parser/Parser.java
+++ b/src/main/java/com/sk89q/worldedit/expression/parser/Parser.java
@@ -95,7 +95,7 @@ public class Parser {
 
                 final Token next = peek();
                 if (next.id() == '(') {
-                    halfProcessed.add(parseFunction(identifierToken));
+                    halfProcessed.add(parseFunctionCall(identifierToken));
                 }
                 else {
                     Invokable variable = variables.get(identifierToken.value);
@@ -301,9 +301,9 @@ public class Parser {
         return tokens.get(position);
     }
 
-    private Identifiable parseFunction(IdentifierToken identifierToken) throws ParserException {
+    private Identifiable parseFunctionCall(IdentifierToken identifierToken) throws ParserException {
         if (peek().id() != '(') {
-            throw new ParserException(peek().getPosition(), "Unexpected character in parseBracket");
+            throw new ParserException(peek().getPosition(), "Unexpected character in parseFunctionCall");
         }
         ++position;