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mirror of https://github.com/DanilaFe/abacus synced 2024-12-22 23:40:08 -08:00

Move parsing code into TreeBuilder, change lexing and parsing algorithms

This commit is contained in:
Danila Fedorin 2017-07-27 12:53:58 -07:00
parent 4eff4760e5
commit 7d822a3e77
6 changed files with 153 additions and 162 deletions

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

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@ -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){
if(TreeNode.precedenceMap.get(((OpNode) right).getOperation()) >
TreeNode.precedenceMap.get(operation)) {
rightString = "(" + rightString + ")";
}
}
return leftString + operation + rightString;
return "(" + leftString + operation + rightString + ")";
}
}

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@ -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.

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@ -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);
}
}

View File

@ -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);
}

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@ -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;