Renamed project to 7Units

1 files changed, 0 insertions, 735 deletions

diff --git a/src/main/java/org/unitConverter/math/ExpressionParser.java b/src/main/java/org/unitConverter/math/ExpressionParser.java
deleted file mode 100644
index deee51d..0000000
--- a/src/main/java/org/unitConverter/math/ExpressionParser.java
+++ /dev/null
@@ -1,735 +0,0 @@
-/**
- * Copyright (C) 2019 Adrien Hopkins
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.unitConverter.math;
-
-import java.util.ArrayDeque;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Deque;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.function.BinaryOperator;
-import java.util.function.Function;
-import java.util.function.UnaryOperator;
-
-/**
- * An object that can parse expressions with unary or binary operators.
- * 
- * @author Adrien Hopkins
- * @param <T> type of object that exists in parsed expressions
- * @since 2019-03-14
- * @since v0.2.0
- */
-public final class ExpressionParser<T> {
-	/**
-	 * A builder that can create {@code ExpressionParser<T>} instances.
-	 * 
-	 * @author Adrien Hopkins
-	 * @param <T> type of object that exists in parsed expressions
-	 * @since 2019-03-17
-	 * @since v0.2.0
-	 */
-	public static final class Builder<T> {
-		/**
-		 * A function that obtains a parseable object from a string. For example,
-		 * an integer {@code ExpressionParser} would use
-		 * {@code Integer::parseInt}.
-		 * 
-		 * @since 2019-03-14
-		 * @since v0.2.0
-		 */
-		private final Function<String, ? extends T> objectObtainer;
-		
-		/**
-		 * The function of the space as an operator (like 3 x y)
-		 * 
-		 * @since 2019-03-22
-		 * @since v0.2.0
-		 */
-		private String spaceFunction = null;
-		
-		/**
-		 * A map mapping operator strings to operator functions, for unary
-		 * operators.
-		 * 
-		 * @since 2019-03-14
-		 * @since v0.2.0
-		 */
-		private final Map<String, PriorityUnaryOperator<T>> unaryOperators;
-		
-		/**
-		 * A map mapping operator strings to operator functions, for binary
-		 * operators.
-		 * 
-		 * @since 2019-03-14
-		 * @since v0.2.0
-		 */
-		private final Map<String, PriorityBinaryOperator<T>> binaryOperators;
-		
-		/**
-		 * Creates the {@code Builder}.
-		 * 
-		 * @param objectObtainer a function that can turn strings into objects of
-		 *                       the type handled by the parser.
-		 * @throws NullPointerException if {@code objectObtainer} is null
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		public Builder(final Function<String, ? extends T> objectObtainer) {
-			this.objectObtainer = Objects.requireNonNull(objectObtainer,
-					"objectObtainer must not be null.");
-			this.unaryOperators = new HashMap<>();
-			this.binaryOperators = new HashMap<>();
-		}
-		
-		/**
-		 * Adds a binary operator to the builder.
-		 * 
-		 * @param text     text used to reference the operator, like '+'
-		 * @param operator operator to add
-		 * @param priority operator's priority, which determines which operators
-		 *                 are applied first
-		 * @return this builder
-		 * @throws NullPointerException if {@code text} or {@code operator} is
-		 *                              null
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		public Builder<T> addBinaryOperator(final String text,
-				final BinaryOperator<T> operator, final int priority) {
-			Objects.requireNonNull(text, "text must not be null.");
-			Objects.requireNonNull(operator, "operator must not be null.");
-			
-			// Unfortunately, I cannot use a lambda because the
-			// PriorityBinaryOperator requires arguments.
-			final PriorityBinaryOperator<T> priorityOperator = new PriorityBinaryOperator<>(
-					priority) {
-				@Override
-				public T apply(final T t, final T u) {
-					return operator.apply(t, u);
-				}
-				
-			};
-			this.binaryOperators.put(text, priorityOperator);
-			return this;
-		}
-		
-		/**
-		 * Adds a function for spaces. You must use the text of an existing binary
-		 * operator.
-		 * 
-		 * @param operator text of operator to use
-		 * @return this builder
-		 * @since 2019-03-22
-		 * @since v0.2.0
-		 */
-		public Builder<T> addSpaceFunction(final String operator) {
-			Objects.requireNonNull(operator, "operator must not be null.");
-			
-			if (!this.binaryOperators.containsKey(operator))
-				throw new IllegalArgumentException(String
-						.format("Could not find binary operator '%s'", operator));
-			
-			this.spaceFunction = operator;
-			return this;
-		}
-		
-		/**
-		 * Adds a unary operator to the builder.
-		 * 
-		 * @param text     text used to reference the operator, like '-'
-		 * @param operator operator to add
-		 * @param priority operator's priority, which determines which operators
-		 *                 are applied first
-		 * @return this builder
-		 * @throws NullPointerException if {@code text} or {@code operator} is
-		 *                              null
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		public Builder<T> addUnaryOperator(final String text,
-				final UnaryOperator<T> operator, final int priority) {
-			Objects.requireNonNull(text, "text must not be null.");
-			Objects.requireNonNull(operator, "operator must not be null.");
-			
-			// Unfortunately, I cannot use a lambda because the
-			// PriorityUnaryOperator requires arguments.
-			final PriorityUnaryOperator<T> priorityOperator = new PriorityUnaryOperator<>(
-					priority) {
-				@Override
-				public T apply(final T t) {
-					return operator.apply(t);
-				}
-			};
-			this.unaryOperators.put(text, priorityOperator);
-			return this;
-		}
-		
-		/**
-		 * @return an {@code ExpressionParser<T>} instance with the properties
-		 *         given to this builder
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		public ExpressionParser<T> build() {
-			return new ExpressionParser<>(this.objectObtainer, this.unaryOperators,
-					this.binaryOperators, this.spaceFunction);
-		}
-	}
-	
-	/**
-	 * A binary operator with a priority field that determines which operators
-	 * apply first.
-	 * 
-	 * @author Adrien Hopkins
-	 * @param <T> type of operand and result
-	 * @since 2019-03-17
-	 * @since v0.2.0
-	 */
-	private static abstract class PriorityBinaryOperator<T>
-			implements BinaryOperator<T>, Comparable<PriorityBinaryOperator<T>> {
-		/**
-		 * The operator's priority. Higher-priority operators are applied before
-		 * lower-priority operators
-		 * 
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		private final int priority;
-		
-		/**
-		 * Creates the {@code PriorityBinaryOperator}.
-		 * 
-		 * @param priority operator's priority
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		public PriorityBinaryOperator(final int priority) {
-			this.priority = priority;
-		}
-		
-		/**
-		 * Compares this object to another by priority.
-		 * 
-		 * <p>
-		 * {@inheritDoc}
-		 * </p>
-		 * 
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		@Override
-		public int compareTo(final PriorityBinaryOperator<T> o) {
-			if (this.priority < o.priority)
-				return -1;
-			else if (this.priority > o.priority)
-				return 1;
-			else
-				return 0;
-		}
-		
-		/**
-		 * @return priority
-		 * @since 2019-03-22
-		 * @since v0.2.0
-		 */
-		public final int getPriority() {
-			return this.priority;
-		}
-	}
-	
-	/**
-	 * A unary operator with a priority field that determines which operators
-	 * apply first.
-	 * 
-	 * @author Adrien Hopkins
-	 * @param <T> type of operand and result
-	 * @since 2019-03-17
-	 * @since v0.2.0
-	 */
-	private static abstract class PriorityUnaryOperator<T>
-			implements UnaryOperator<T>, Comparable<PriorityUnaryOperator<T>> {
-		/**
-		 * The operator's priority. Higher-priority operators are applied before
-		 * lower-priority operators
-		 * 
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		private final int priority;
-		
-		/**
-		 * Creates the {@code PriorityUnaryOperator}.
-		 * 
-		 * @param priority operator's priority
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		public PriorityUnaryOperator(final int priority) {
-			this.priority = priority;
-		}
-		
-		/**
-		 * Compares this object to another by priority.
-		 * 
-		 * <p>
-		 * {@inheritDoc}
-		 * </p>
-		 * 
-		 * @since 2019-03-17
-		 * @since v0.2.0
-		 */
-		@Override
-		public int compareTo(final PriorityUnaryOperator<T> o) {
-			if (this.priority < o.priority)
-				return -1;
-			else if (this.priority > o.priority)
-				return 1;
-			else
-				return 0;
-		}
-		
-		/**
-		 * @return priority
-		 * @since 2019-03-22
-		 * @since v0.2.0
-		 */
-		public final int getPriority() {
-			return this.priority;
-		}
-	}
-	
-	/**
-	 * The types of tokens that are available.
-	 * 
-	 * @author Adrien Hopkins
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private static enum TokenType {
-		OBJECT, UNARY_OPERATOR, BINARY_OPERATOR;
-	}
-	
-	/**
-	 * The opening bracket.
-	 * 
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	public static final char OPENING_BRACKET = '(';
-	
-	/**
-	 * The closing bracket.
-	 * 
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	public static final char CLOSING_BRACKET = ')';
-	
-	/**
-	 * Finds the other bracket in a pair of brackets, given the position of one.
-	 * 
-	 * @param string          string that contains brackets
-	 * @param bracketPosition position of first bracket
-	 * @return position of matching bracket
-	 * @throws NullPointerException if string is null
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	private static int findBracketPair(final String string,
-			final int bracketPosition) {
-		Objects.requireNonNull(string, "string must not be null.");
-		
-		final char openingBracket = string.charAt(bracketPosition);
-		
-		// figure out what closing bracket to look for
-		final char closingBracket;
-		switch (openingBracket) {
-		case '(':
-			closingBracket = ')';
-			break;
-		case '[':
-			closingBracket = ']';
-			break;
-		case '{':
-			closingBracket = '}';
-			break;
-		default:
-			throw new IllegalArgumentException(
-					String.format("Invalid bracket '%s'", openingBracket));
-		}
-		
-		// level of brackets. every opening bracket increments this; every closing
-		// bracket decrements it
-		int bracketLevel = 0;
-		
-		// iterate over the string to find the closing bracket
-		for (int currentPosition = bracketPosition; currentPosition < string
-				.length(); currentPosition++) {
-			final char currentCharacter = string.charAt(currentPosition);
-			
-			if (currentCharacter == openingBracket) {
-				bracketLevel++;
-			} else if (currentCharacter == closingBracket) {
-				bracketLevel--;
-				if (bracketLevel == 0)
-					return currentPosition;
-			}
-		}
-		
-		throw new IllegalArgumentException("No matching bracket found.");
-	}
-	
-	/**
-	 * A function that obtains a parseable object from a string. For example, an
-	 * integer {@code ExpressionParser} would use {@code Integer::parseInt}.
-	 * 
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private final Function<String, ? extends T> objectObtainer;
-	
-	/**
-	 * A map mapping operator strings to operator functions, for unary operators.
-	 * 
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private final Map<String, PriorityUnaryOperator<T>> unaryOperators;
-	
-	/**
-	 * A map mapping operator strings to operator functions, for binary
-	 * operators.
-	 * 
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private final Map<String, PriorityBinaryOperator<T>> binaryOperators;
-	
-	/**
-	 * The operator for space, or null if spaces have no function.
-	 * 
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	private final String spaceOperator;
-	
-	/**
-	 * Creates the {@code ExpressionParser}.
-	 * 
-	 * @param objectObtainer  function to get objects from strings
-	 * @param unaryOperators  unary operators available to the parser
-	 * @param binaryOperators binary operators available to the parser
-	 * @param spaceOperator   operator used by spaces
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private ExpressionParser(final Function<String, ? extends T> objectObtainer,
-			final Map<String, PriorityUnaryOperator<T>> unaryOperators,
-			final Map<String, PriorityBinaryOperator<T>> binaryOperators,
-			final String spaceOperator) {
-		this.objectObtainer = objectObtainer;
-		this.unaryOperators = unaryOperators;
-		this.binaryOperators = binaryOperators;
-		this.spaceOperator = spaceOperator;
-	}
-	
-	/**
-	 * Converts a given mathematical expression to reverse Polish notation
-	 * (operators after operands).
-	 * <p>
-	 * For example,<br>
-	 * {@code 2 * (3 + 4)}<br>
-	 * becomes<br>
-	 * {@code 2 3 4 + *}.
-	 * 
-	 * @param expression expression
-	 * @return expression in RPN
-	 * @since 2019-03-17
-	 * @since v0.2.0
-	 */
-	private String convertExpressionToReversePolish(final String expression) {
-		Objects.requireNonNull(expression, "expression must not be null.");
-		
-		final List<String> components = new ArrayList<>();
-		
-		// the part of the expression remaining to parse
-		String partialExpression = expression;
-		
-		// find and deal with brackets
-		while (partialExpression.indexOf(OPENING_BRACKET) != -1) {
-			final int openingBracketPosition = partialExpression
-					.indexOf(OPENING_BRACKET);
-			final int closingBracketPosition = findBracketPair(partialExpression,
-					openingBracketPosition);
-			
-			// check for function
-			if (openingBracketPosition > 0
-					&& partialExpression.charAt(openingBracketPosition - 1) != ' ') {
-				// function like sin(2) or tempF(32)
-				// find the position of the last space
-				int spacePosition = openingBracketPosition;
-				while (spacePosition >= 0
-						&& partialExpression.charAt(spacePosition) != ' ') {
-					spacePosition--;
-				}
-				// then split the function into pre-function and function, using the
-				// space position
-				components.addAll(Arrays.asList(partialExpression
-						.substring(0, spacePosition + 1).split(" ")));
-				components.add(partialExpression.substring(spacePosition + 1,
-						closingBracketPosition + 1));
-				partialExpression = partialExpression
-						.substring(closingBracketPosition + 1);
-			} else {
-				// normal brackets like (1 + 2) * (3 / 5)
-				components.addAll(Arrays.asList(partialExpression
-						.substring(0, openingBracketPosition).split(" ")));
-				components.add(this.convertExpressionToReversePolish(
-						partialExpression.substring(openingBracketPosition + 1,
-								closingBracketPosition)));
-				partialExpression = partialExpression
-						.substring(closingBracketPosition + 1);
-			}
-		}
-		
-		// add everything else
-		components.addAll(Arrays.asList(partialExpression.split(" ")));
-		
-		// remove empty entries
-		while (components.contains("")) {
-			components.remove("");
-		}
-		
-		// deal with space multiplication (x y)
-		if (this.spaceOperator != null) {
-			for (int i = 0; i < components.size() - 1; i++) {
-				if (this.getTokenType(components.get(i)) == TokenType.OBJECT && this
-						.getTokenType(components.get(i + 1)) == TokenType.OBJECT) {
-					components.add(++i, this.spaceOperator);
-				}
-			}
-		}
-		
-		// turn the expression into reverse Polish
-		while (true) {
-			final int highestPriorityOperatorPosition = this
-					.findHighestPriorityOperatorPosition(components);
-			if (highestPriorityOperatorPosition == -1) {
-				break;
-			}
-			
-			// swap components based on what kind of operator there is
-			// 1 + 2 becomes 2 1 +
-			// - 1 becomes 1 -
-			switch (this
-					.getTokenType(components.get(highestPriorityOperatorPosition))) {
-			case UNARY_OPERATOR:
-				final String unaryOperator = components
-						.remove(highestPriorityOperatorPosition);
-				final String operand = components
-						.remove(highestPriorityOperatorPosition);
-				components.add(highestPriorityOperatorPosition,
-						operand + " " + unaryOperator);
-				break;
-			case BINARY_OPERATOR:
-				final String binaryOperator = components
-						.remove(highestPriorityOperatorPosition);
-				final String operand1 = components
-						.remove(highestPriorityOperatorPosition - 1);
-				final String operand2 = components
-						.remove(highestPriorityOperatorPosition - 1);
-				components.add(highestPriorityOperatorPosition - 1,
-						operand2 + " " + operand1 + " " + binaryOperator);
-				break;
-			default:
-				throw new AssertionError("Expected operator, found non-operator.");
-			}
-		}
-		
-		// join all of the components together, then ensure there is only one
-		// space in a row
-		String expressionRPN = String.join(" ", components).replaceAll(" +", " ");
-		
-		while (expressionRPN.charAt(0) == ' ') {
-			expressionRPN = expressionRPN.substring(1);
-		}
-		while (expressionRPN.charAt(expressionRPN.length() - 1) == ' ') {
-			expressionRPN = expressionRPN.substring(0, expressionRPN.length() - 1);
-		}
-		return expressionRPN;
-	}
-	
-	/**
-	 * Finds the position of the highest-priority operator in a list
-	 * 
-	 * @param components components to test
-	 * @param blacklist  positions of operators that should be ignored
-	 * @return position of highest priority, or -1 if the list contains no
-	 *         operators
-	 * @throws NullPointerException if components is null
-	 * @since 2019-03-22
-	 * @since v0.2.0
-	 */
-	private int findHighestPriorityOperatorPosition(
-			final List<String> components) {
-		Objects.requireNonNull(components, "components must not be null.");
-		// find highest priority
-		int maxPriority = Integer.MIN_VALUE;
-		int maxPriorityPosition = -1;
-		
-		// go over components one by one
-		// if it is an operator, test its priority to see if it's max
-		// if it is, update maxPriority and maxPriorityPosition
-		for (int i = 0; i < components.size(); i++) {
-			
-			switch (this.getTokenType(components.get(i))) {
-			case UNARY_OPERATOR:
-				final PriorityUnaryOperator<T> unaryOperator = this.unaryOperators
-						.get(components.get(i));
-				final int unaryPriority = unaryOperator.getPriority();
-				
-				if (unaryPriority > maxPriority) {
-					maxPriority = unaryPriority;
-					maxPriorityPosition = i;
-				}
-				break;
-			case BINARY_OPERATOR:
-				final PriorityBinaryOperator<T> binaryOperator = this.binaryOperators
-						.get(components.get(i));
-				final int binaryPriority = binaryOperator.getPriority();
-				
-				if (binaryPriority > maxPriority) {
-					maxPriority = binaryPriority;
-					maxPriorityPosition = i;
-				}
-				break;
-			default:
-				break;
-			}
-		}
-		
-		// max priority position found
-		return maxPriorityPosition;
-	}
-	
-	/**
-	 * Determines whether an inputted string is an object or an operator
-	 * 
-	 * @param token string to input
-	 * @return type of token it is
-	 * @throws NullPointerException if {@code expression} is null
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private TokenType getTokenType(final String token) {
-		Objects.requireNonNull(token, "token must not be null.");
-		
-		if (this.unaryOperators.containsKey(token))
-			return TokenType.UNARY_OPERATOR;
-		else if (this.binaryOperators.containsKey(token))
-			return TokenType.BINARY_OPERATOR;
-		else
-			return TokenType.OBJECT;
-	}
-	
-	/**
-	 * Parses an expression.
-	 * 
-	 * @param expression expression to parse
-	 * @return result
-	 * @throws NullPointerException if {@code expression} is null
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	public T parseExpression(final String expression) {
-		return this.parseReversePolishExpression(
-				this.convertExpressionToReversePolish(expression));
-	}
-	
-	/**
-	 * Parses an expression expressed in reverse Polish notation.
-	 * 
-	 * @param expression expression to parse
-	 * @return result
-	 * @throws NullPointerException if {@code expression} is null
-	 * @since 2019-03-14
-	 * @since v0.2.0
-	 */
-	private T parseReversePolishExpression(final String expression) {
-		Objects.requireNonNull(expression, "expression must not be null.");
-		
-		final Deque<T> stack = new ArrayDeque<>();
-		
-		// iterate over every item in the expression, then
-		for (final String item : expression.split(" ")) {
-			// choose a path based on what kind of thing was just read
-			switch (this.getTokenType(item)) {
-			
-			case BINARY_OPERATOR:
-				if (stack.size() < 2)
-					throw new IllegalStateException(String.format(
-							"Attempted to call binary operator %s with only %d arguments.",
-							item, stack.size()));
-				
-				// get two arguments and operator, then apply!
-				final T o1 = stack.pop();
-				final T o2 = stack.pop();
-				final BinaryOperator<T> binaryOperator = this.binaryOperators
-						.get(item);
-				
-				stack.push(binaryOperator.apply(o1, o2));
-				break;
-			
-			case OBJECT:
-				// just add it to the stack
-				stack.push(this.objectObtainer.apply(item));
-				break;
-			
-			case UNARY_OPERATOR:
-				if (stack.size() < 1)
-					throw new IllegalStateException(String.format(
-							"Attempted to call unary operator %s with only %d arguments.",
-							item, stack.size()));
-				
-				// get one argument and operator, then apply!
-				final T o = stack.pop();
-				final UnaryOperator<T> unaryOperator = this.unaryOperators
-						.get(item);
-				
-				stack.push(unaryOperator.apply(o));
-				break;
-			default:
-				throw new AssertionError(
-						String.format("Internal error: Invalid token type %s.",
-								this.getTokenType(item)));
-			
-			}
-		}
-		
-		// return answer, or throw an exception if I can't
-		if (stack.size() > 1)
-			throw new IllegalStateException(
-					"Computation ended up with more than one answer.");
-		else if (stack.size() == 0)
-			throw new IllegalStateException(
-					"Computation ended up without an answer.");
-		return stack.pop();
-	}
-}