Move parsing code into TreeBuilder, change lexing and parsing algorithms

src/org/nwapw/abacus/plugin/PluginManager.java

@@ -33,6 +33,7 @@ public class PluginManager {
     public PluginManager(){
         plugins = new ArrayList<>();
         cachedFunctions = new HashMap<>();
+        cachedOperators = new HashMap<>();
     }
 
     /**

src/org/nwapw/abacus/tree/OpNode.java

@@ -95,13 +95,6 @@ public class OpNode extends TreeNode {
         String leftString = left != null ? left.toString() : "null";
         String rightString = right != null ? right.toString() : "null";
 
-        if(right != null && right instanceof OpNode){
+        return "(" + leftString + operation + rightString + ")";
-            if(TreeNode.precedenceMap.get(((OpNode) right).getOperation()) >
-                    TreeNode.precedenceMap.get(operation)) {
-                rightString = "(" + rightString + ")";
-            }
-        }
-        
-        return leftString + operation + rightString;
     }
 }

src/org/nwapw/abacus/tree/TokenType.java

@@ -6,7 +6,8 @@ package org.nwapw.abacus.tree;
  */
 public enum TokenType {
 
-    INTERNAL_FUNCTION_END(-1), INTERNAL_FUNCTION_START(-1), ANY(0), COMMA(1), OP(2), NUM(3), WORD(4), OPEN_PARENTH(5), CLOSE_PARENTH(6);
+    INTERNAL_FUNCTION_END(-1),
+    ANY(0), COMMA(1), OP(2), NUM(3), FUNCTION(4), OPEN_PARENTH(5), CLOSE_PARENTH(6);
 
     /**
      * The priority by which this token gets sorted.

src/org/nwapw/abacus/tree/TreeBuilder.java

@@ -0,0 +1,142 @@
+package org.nwapw.abacus.tree;
+
+import org.nwapw.abacus.function.OperatorAssociativity;
+import org.nwapw.abacus.lexing.Lexer;
+import org.nwapw.abacus.lexing.pattern.Match;
+import org.nwapw.abacus.plugin.PluginManager;
+
+import java.util.*;
+
+public class TreeBuilder {
+
+    private Lexer<TokenType> lexer;
+    private HashMap<String, Integer> precedenceMap;
+    private HashMap<String, OperatorAssociativity> associativityMap;
+
+    /**
+     * Comparator used to sort token types.
+     */
+    protected static Comparator<TokenType> tokenSorter = Comparator.comparingInt(e -> e.priority);
+
+    public TreeBuilder(){
+        lexer = new Lexer<TokenType>(){{
+            register(",", TokenType.COMMA);
+            register("[0-9]+(\\.[0-9]+)?", TokenType.NUM);
+            register("\\(", TokenType.OPEN_PARENTH);
+            register("\\)", TokenType.CLOSE_PARENTH);
+        }};
+        precedenceMap = new HashMap<>();
+        associativityMap = new HashMap<>();
+    }
+
+    /**
+     * Tokenizes a string, converting it into matches
+     * @param string the string to tokenize.
+     * @return the list of tokens produced.
+     */
+    public ArrayList<Match<TokenType>> tokenize(String string){
+        return lexer.lexAll(string, 0, tokenSorter);
+    }
+
+    /**
+     * Rearranges tokens into a postfix list, using Shunting Yard.
+     * @param source the source string.
+     * @param from the tokens to be rearranged.
+     * @return the resulting list of rearranged tokens.
+     */
+    public ArrayList<Match<TokenType>> intoPostfix(String source, ArrayList<Match<TokenType>> from){
+        ArrayList<Match<TokenType>> output = new ArrayList<>();
+        Stack<Match<TokenType>> tokenStack = new Stack<>();
+        while(!from.isEmpty()){
+            Match<TokenType> match = from.remove(0);
+            TokenType matchType = match.getType();
+            if(matchType == TokenType.NUM) {
+                output.add(match);
+            } else if(matchType == TokenType.FUNCTION) {
+                output.add(new Match<>(0, 0, TokenType.INTERNAL_FUNCTION_END));
+                tokenStack.push(match);
+            } else if(matchType == TokenType.OP){
+                String tokenString = source.substring(match.getFrom(), match.getTo());
+                int precedence = precedenceMap.get(tokenString);
+                OperatorAssociativity associativity = associativityMap.get(tokenString);
+
+                while(!tokenStack.empty()) {
+                    Match<TokenType> otherMatch = tokenStack.peek();
+                    TokenType otherMatchType = otherMatch.getType();
+                    if(otherMatchType != TokenType.OP) break;
+
+                    int otherPrecdence = precedenceMap.get(source.substring(otherMatch.getFrom(), otherMatch.getTo()));
+                    if(otherPrecdence < precedence ||
+                            (associativity == OperatorAssociativity.RIGHT && otherPrecdence == precedence)) {
+                        break;
+                    }
+                    output.add(tokenStack.pop());
+                }
+                tokenStack.push(match);
+            } else if(matchType == TokenType.OPEN_PARENTH){
+                tokenStack.push(match);
+            } else if(matchType == TokenType.CLOSE_PARENTH || matchType == TokenType.COMMA){
+                while(!tokenStack.empty() && tokenStack.peek().getType() != TokenType.OPEN_PARENTH){
+                    output.add(tokenStack.pop());
+                }
+                if(tokenStack.empty()) return null;
+                if(matchType == TokenType.CLOSE_PARENTH){
+                    tokenStack.pop();
+                }
+            }
+        }
+        while(!tokenStack.empty()){
+            if(!(tokenStack.peek().getType() == TokenType.OP)) return null;
+            output.add(tokenStack.pop());
+        }
+        return output;
+    }
+
+    /**
+     * Constructs a tree recursively from a list of tokens.
+     * @param source the source string.
+     * @param matches the list of tokens from the source string.
+     * @return the construct tree expression.
+     */
+    public TreeNode fromStringRecursive(String source, ArrayList<Match<TokenType>> matches){
+        if(matches.size() == 0) return null;
+        Match<TokenType> match = matches.remove(0);
+        TokenType matchType = match.getType();
+        if(matchType == TokenType.OP){
+            TreeNode right = fromStringRecursive(source, matches);
+            TreeNode left = fromStringRecursive(source, matches);
+            if(left == null || right == null) return null;
+            else return new OpNode(source.substring(match.getFrom(), match.getTo()), left, right);
+        } else if(matchType == TokenType.NUM){
+            return new NumberNode(Double.parseDouble(source.substring(match.getFrom(), match.getTo())));
+        } else if(matchType == TokenType.FUNCTION){
+            String functionName = source.substring(match.getFrom(), match.getTo());
+            FunctionNode node = new FunctionNode(functionName);
+            while(!matches.isEmpty() && matches.get(0).getType() != TokenType.INTERNAL_FUNCTION_END){
+                TreeNode argument = fromStringRecursive(source, matches);
+                if(argument == null) return null;
+                node.addChild(argument);
+            }
+            if(matches.isEmpty()) return null;
+            matches.remove(0);
+            return node;
+        }
+        return null;
+    }
+
+    /**
+     * Creates a tree node from a string.
+     * @param string the string to create a node from.
+     * @return the resulting tree.
+     */
+    public TreeNode fromString(String string){
+        ArrayList<Match<TokenType>> matches = tokenize(string);
+        if(matches == null) return null;
+        matches = intoPostfix(string, matches);
+        if(matches == null) return null;
+
+        Collections.reverse(matches);
+        return fromStringRecursive(string, matches);
+    }
+
+}

src/org/nwapw/abacus/tree/TreeNode.java

@@ -11,158 +11,6 @@ import java.util.*;
  */
 public abstract class TreeNode {
 
-    /**
-     * The lexer used to lex tokens.
-     */
-    protected static Lexer<TokenType> lexer = new Lexer<TokenType>(){{
-        register(",", TokenType.COMMA);
-        register("\\+|-|\\*|/", TokenType.OP);
-        register("[0-9]+(\\.[0-9]+)?", TokenType.NUM);
-        register("[a-zA-Z]+", TokenType.WORD);
-        register("\\(", TokenType.OPEN_PARENTH);
-        register("\\)", TokenType.CLOSE_PARENTH);
-    }};
-    /**
-     * A map that maps operations to their precedence.
-     */
-    protected static HashMap<String, Integer> precedenceMap = new HashMap<String, Integer>(){{
-        put("+", 0);
-        put("-", 0);
-        put("*", 1);
-        put("/", 1);
-    }};
-    /**
-     * A map that maps operations to their associativity.
-     */
-    protected static HashMap<String, OperatorAssociativity> associativityMap =
-            new HashMap<String, OperatorAssociativity>() {{
-                put("+", OperatorAssociativity.LEFT);
-                put("-", OperatorAssociativity.LEFT);
-                put("*", OperatorAssociativity.LEFT);
-                put("/", OperatorAssociativity.LEFT);
-            }};
-
-    /**
-     * Comparator used to sort token types.
-     */
-    protected static Comparator<TokenType> tokenSorter = Comparator.comparingInt(e -> e.priority);
-
-    /**
-     * Tokenizes a string, converting it into matches
-     * @param string the string to tokenize.
-     * @return the list of tokens produced.
-     */
-    public static ArrayList<Match<TokenType>> tokenize(String string){
-        return lexer.lexAll(string, 0, tokenSorter);
-    }
-
-    /**
-     * Rearranges tokens into a postfix list, using Shunting Yard.
-     * @param source the source string.
-     * @param from the tokens to be rearranged.
-     * @return the resulting list of rearranged tokens.
-     */
-    public static ArrayList<Match<TokenType>> intoPostfix(String source, ArrayList<Match<TokenType>> from){
-        ArrayList<Match<TokenType>> output = new ArrayList<>();
-        Stack<Match<TokenType>> tokenStack = new Stack<>();
-        while(!from.isEmpty()){
-            Match<TokenType> match = from.remove(0);
-            TokenType matchType = match.getType();
-            if(matchType == TokenType.NUM || matchType == TokenType.WORD) {
-                output.add(match);
-            } else if(matchType == TokenType.OP){
-                String tokenString = source.substring(match.getFrom(), match.getTo());
-                int precedence = precedenceMap.get(tokenString);
-                OperatorAssociativity associativity = associativityMap.get(tokenString);
-
-                while(!tokenStack.empty()) {
-                    Match<TokenType> otherMatch = tokenStack.peek();
-                    if(otherMatch.getType() != TokenType.OP) break;
-
-                    int otherPrecdence = precedenceMap.get(source.substring(otherMatch.getFrom(), otherMatch.getTo()));
-                    if(otherPrecdence < precedence ||
-                            (associativity == OperatorAssociativity.RIGHT && otherPrecdence == precedence)) {
-                        break;
-                    }
-                    output.add(tokenStack.pop());
-                }
-                tokenStack.push(match);
-            } else if(matchType == TokenType.OPEN_PARENTH){
-                if(!output.isEmpty() && output.get(output.size() - 1).getType() == TokenType.WORD){
-                    tokenStack.push(output.remove(output.size() - 1));
-                    output.add(new Match<>(0, 0, TokenType.INTERNAL_FUNCTION_END));
-                }
-                tokenStack.push(match);
-            } else if(matchType == TokenType.CLOSE_PARENTH || matchType == TokenType.COMMA){
-                while(!tokenStack.empty() && tokenStack.peek().getType() != TokenType.OPEN_PARENTH){
-                    output.add(tokenStack.pop());
-                }
-                if(tokenStack.empty()) return null;
-                if(matchType == TokenType.CLOSE_PARENTH){
-                    tokenStack.pop();
-                    if(!tokenStack.empty() && tokenStack.peek().getType() == TokenType.WORD) {
-                        output.add(tokenStack.pop());
-                        output.add(new Match<>(0, 0, TokenType.INTERNAL_FUNCTION_START));
-                    }
-                }
-            }
-        }
-        while(!tokenStack.empty()){
-            if(!(tokenStack.peek().getType() == TokenType.OP)) return null;
-            output.add(tokenStack.pop());
-        }
-        return output;
-    }
-
-    /**
-     * Constructs a tree recursively from a list of tokens.
-     * @param source the source string.
-     * @param matches the list of tokens from the source string.
-     * @return the construct tree expression.
-     */
-    public static TreeNode fromStringRecursive(String source, ArrayList<Match<TokenType>> matches){
-        if(matches.size() == 0) return null;
-        Match<TokenType> match = matches.remove(0);
-        TokenType matchType = match.getType();
-        if(matchType == TokenType.OP){
-            TreeNode right = fromStringRecursive(source, matches);
-            TreeNode left = fromStringRecursive(source, matches);
-            if(left == null || right == null) return null;
-            else return new OpNode(source.substring(match.getFrom(), match.getTo()), left, right);
-        } else if(matchType == TokenType.NUM){
-            return new NumberNode(Double.parseDouble(source.substring(match.getFrom(), match.getTo())));
-        } else if(matchType == TokenType.INTERNAL_FUNCTION_START){
-            if(matches.isEmpty() || matches.get(0).getType() != TokenType.WORD) return null;
-            Match<TokenType> stringName = matches.remove(0);
-            String functionName = source.substring(stringName.getFrom(), stringName.getTo());
-            FunctionNode node = new FunctionNode(functionName);
-            while(!matches.isEmpty() && matches.get(0).getType() != TokenType.INTERNAL_FUNCTION_END){
-                TreeNode argument = fromStringRecursive(source, matches);
-                if(argument == null) return null;
-                node.addChild(argument);
-            }
-            if(matches.isEmpty()) return null;
-            matches.remove(0);
-            return node;
-        }
-        return null;
-    }
-
-    /**
-     * Creates a tree node from a string.
-     * @param string the string to create a node from.
-     * @return the resulting tree.
-     */
-    public static TreeNode fromString(String string){
-        ArrayList<Match<TokenType>> matches = tokenize(string);
-        if(matches == null) return null;
-        matches = intoPostfix(string, matches);
-        if(matches == null) return null;
-
-        Collections.reverse(matches);
-        return fromStringRecursive(string, matches);
-    }
-
     public abstract <T> T reduce(Reducer<T> reducer);
 
 }

src/org/nwapw/abacus/window/Window.java

@@ -3,6 +3,7 @@ package org.nwapw.abacus.window;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.plugin.PluginManager;
 import org.nwapw.abacus.tree.NumberReducer;
+import org.nwapw.abacus.tree.TreeBuilder;
 import org.nwapw.abacus.tree.TreeNode;
 
 import javax.swing.*;
@@ -47,6 +48,10 @@ public class Window extends JFrame {
      * The plugin manager used to retrieve functions.
      */
     private PluginManager manager;
+    /**
+     * The builder used to construct the parse trees.
+     */
+    private TreeBuilder builder;
     /**
      * The reducer used to evaluate the tree.
      */
@@ -123,7 +128,8 @@ public class Window extends JFrame {
      * Action listener that causes the input to be evaluated.
      */
     private ActionListener evaluateListener = (event) -> {
-        TreeNode parsedExpression = TreeNode.fromString(inputField.getText());
+        TreeBuilder builder = new TreeBuilder();
+        TreeNode parsedExpression = builder.fromString(inputField.getText());
         if(parsedExpression == null){
             lastOutputArea.setText(SYNTAX_ERR_STRING);
             return;