diff options
| -rw-r--r-- | src/main/java/sevenUnits/utils/ExpressionParser.java | 188 |
1 files changed, 93 insertions, 95 deletions
diff --git a/src/main/java/sevenUnits/utils/ExpressionParser.java b/src/main/java/sevenUnits/utils/ExpressionParser.java index 051082d..783a135 100644 --- a/src/main/java/sevenUnits/utils/ExpressionParser.java +++ b/src/main/java/sevenUnits/utils/ExpressionParser.java @@ -56,7 +56,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final Function<String, ? extends T> objectObtainer; - + /** * The function of the space as an operator (like 3 x y) * @@ -64,7 +64,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private String spaceFunction = null; - + /** * A map mapping operator strings to operator functions, for unary * operators. @@ -73,7 +73,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final Map<String, PriorityUnaryOperator<T>> unaryOperators; - + /** * A map mapping operator strings to operator functions, for binary * operators. @@ -82,7 +82,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final Map<String, PriorityBinaryOperator<T>> binaryOperators; - + /** * A map mapping operator strings to numeric functions. * @@ -90,7 +90,7 @@ public final class ExpressionParser<T> { * @since v0.5.0 */ private final Map<String, PriorityBiFunction<T, UncertainDouble, T>> numericOperators; - + /** * Creates the {@code Builder}. * @@ -107,7 +107,7 @@ public final class ExpressionParser<T> { this.binaryOperators = new HashMap<>(); this.numericOperators = new HashMap<>(); } - + /** * Adds a binary operator to the builder. * @@ -125,7 +125,7 @@ public final class ExpressionParser<T> { 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<>( @@ -134,12 +134,12 @@ public final class ExpressionParser<T> { public T apply(final T t, final T u) { return operator.apply(t, u); } - + }; this.binaryOperators.put(text, priorityOperator); return this; } - + /** * Adds a two-argument operator where the second operator is a number. * This is used for operations like vector scaling and exponentation. @@ -155,7 +155,7 @@ public final class ExpressionParser<T> { 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 PriorityBiFunction<T, UncertainDouble, T> priorityOperator = new PriorityBiFunction<>( @@ -164,12 +164,12 @@ public final class ExpressionParser<T> { public T apply(final T t, final UncertainDouble u) { return operator.apply(t, u); } - + }; this.numericOperators.put(text, priorityOperator); return this; } - + /** * Adds a function for spaces. You must use the text of an existing binary * operator. @@ -181,15 +181,15 @@ public final class ExpressionParser<T> { */ 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. * @@ -207,7 +207,7 @@ public final class ExpressionParser<T> { 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<>( @@ -220,7 +220,7 @@ public final class ExpressionParser<T> { this.unaryOperators.put(text, priorityOperator); return this; } - + /** * @return an {@code ExpressionParser<T>} instance with the properties * given to this builder @@ -232,7 +232,7 @@ public final class ExpressionParser<T> { this.binaryOperators, this.numericOperators, this.spaceFunction); } } - + /** * A binary operator with a priority field that determines which operators * apply first. @@ -242,8 +242,8 @@ public final class ExpressionParser<T> { * @since 2019-03-17 * @since v0.2.0 */ - private static abstract class PriorityBinaryOperator<T> - implements BinaryOperator<T>, Comparable<PriorityBinaryOperator<T>> { + private static abstract class PriorityBiFunction<T, U, R> implements + BiFunction<T, U, R>, Comparable<PriorityBiFunction<T, U, R>> { /** * The operator's priority. Higher-priority operators are applied before * lower-priority operators @@ -252,7 +252,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final int priority; - + /** * Creates the {@code PriorityBinaryOperator}. * @@ -260,10 +260,10 @@ public final class ExpressionParser<T> { * @since 2019-03-17 * @since v0.2.0 */ - public PriorityBinaryOperator(final int priority) { + public PriorityBiFunction(final int priority) { this.priority = priority; } - + /** * Compares this object to another by priority. * @@ -275,7 +275,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ @Override - public int compareTo(final PriorityBinaryOperator<T> o) { + public int compareTo(final PriorityBiFunction<T, U, R> o) { if (this.priority < o.priority) return -1; else if (this.priority > o.priority) @@ -283,7 +283,7 @@ public final class ExpressionParser<T> { else return 0; } - + /** * @return priority * @since 2019-03-22 @@ -293,7 +293,7 @@ public final class ExpressionParser<T> { return this.priority; } } - + /** * A binary operator with a priority field that determines which operators * apply first. @@ -303,8 +303,8 @@ public final class ExpressionParser<T> { * @since 2019-03-17 * @since v0.2.0 */ - private static abstract class PriorityBiFunction<T, U, R> implements - BiFunction<T, U, R>, Comparable<PriorityBiFunction<T, U, R>> { + 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 @@ -313,7 +313,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final int priority; - + /** * Creates the {@code PriorityBinaryOperator}. * @@ -321,10 +321,10 @@ public final class ExpressionParser<T> { * @since 2019-03-17 * @since v0.2.0 */ - public PriorityBiFunction(final int priority) { + public PriorityBinaryOperator(final int priority) { this.priority = priority; } - + /** * Compares this object to another by priority. * @@ -336,7 +336,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ @Override - public int compareTo(final PriorityBiFunction<T, U, R> o) { + public int compareTo(final PriorityBinaryOperator<T> o) { if (this.priority < o.priority) return -1; else if (this.priority > o.priority) @@ -344,7 +344,7 @@ public final class ExpressionParser<T> { else return 0; } - + /** * @return priority * @since 2019-03-22 @@ -354,7 +354,7 @@ public final class ExpressionParser<T> { return this.priority; } } - + /** * A unary operator with a priority field that determines which operators * apply first. @@ -374,7 +374,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final int priority; - + /** * Creates the {@code PriorityUnaryOperator}. * @@ -385,7 +385,7 @@ public final class ExpressionParser<T> { public PriorityUnaryOperator(final int priority) { this.priority = priority; } - + /** * Compares this object to another by priority. * @@ -405,7 +405,7 @@ public final class ExpressionParser<T> { else return 0; } - + /** * @return priority * @since 2019-03-22 @@ -415,7 +415,7 @@ public final class ExpressionParser<T> { return this.priority; } } - + /** * The types of tokens that are available. * @@ -426,7 +426,7 @@ public final class ExpressionParser<T> { private static enum TokenType { OBJECT, UNARY_OPERATOR, BINARY_OPERATOR, NUMERIC_OPERATOR; } - + /** * The opening bracket. * @@ -434,7 +434,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ public static final char OPENING_BRACKET = '('; - + /** * The closing bracket. * @@ -442,7 +442,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ public static final char CLOSING_BRACKET = ')'; - + /** * Finds the other bracket in a pair of brackets, given the position of one. * @@ -456,9 +456,9 @@ public final class ExpressionParser<T> { 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) { @@ -475,16 +475,16 @@ public final class ExpressionParser<T> { 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) { @@ -493,10 +493,10 @@ public final class ExpressionParser<T> { 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}. @@ -505,7 +505,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final Function<String, ? extends T> objectObtainer; - + /** * A map mapping operator strings to operator functions, for unary operators. * @@ -513,7 +513,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final Map<String, PriorityUnaryOperator<T>> unaryOperators; - + /** * A map mapping operator strings to operator functions, for binary * operators. @@ -522,7 +522,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final Map<String, PriorityBinaryOperator<T>> binaryOperators; - + /** * A map mapping operator strings to numeric functions. * @@ -530,7 +530,7 @@ public final class ExpressionParser<T> { * @since v0.5.0 */ private final Map<String, PriorityBiFunction<T, UncertainDouble, T>> numericOperators; - + /** * The operator for space, or null if spaces have no function. * @@ -538,7 +538,7 @@ public final class ExpressionParser<T> { * @since v0.2.0 */ private final String spaceOperator; - + /** * Creates the {@code ExpressionParser}. * @@ -561,7 +561,7 @@ public final class ExpressionParser<T> { this.numericOperators = numericOperators; this.spaceOperator = spaceOperator; } - + /** * Converts a given mathematical expression to reverse Polish notation * (operators after operands). @@ -578,22 +578,21 @@ public final class ExpressionParser<T> { * @since 2019-03-17 * @since v0.2.0 */ - // TODO revert to package private - public String convertExpressionToReversePolish(final String expression) { + 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) != ' ') { @@ -623,15 +622,15 @@ public final class ExpressionParser<T> { .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++) { @@ -641,7 +640,7 @@ public final class ExpressionParser<T> { } } } - + // turn the expression into reverse Polish while (true) { final int highestPriorityOperatorPosition = this @@ -649,7 +648,7 @@ public final class ExpressionParser<T> { if (highestPriorityOperatorPosition == -1) { break; } - + // swap components based on what kind of operator there is // 1 + 2 becomes 2 1 + // - 1 becomes 1 - @@ -684,16 +683,15 @@ public final class ExpressionParser<T> { throw new AssertionError("Expected operator, found non-operator."); } } - + // join all of the components together, then ensure there is only one // space in a row - if (components.size() != 1) { + if (components.size() != 1) throw new IllegalArgumentException( "Invalid expression \"" + expression + "\"."); - } return components.get(0).replaceAll(" +", " ").trim(); } - + /** * Finds the position of the highest-priority operator in a list * @@ -711,18 +709,18 @@ public final class ExpressionParser<T> { // 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; @@ -732,7 +730,7 @@ public final class ExpressionParser<T> { final PriorityBinaryOperator<T> binaryOperator = this.binaryOperators .get(components.get(i)); final int binaryPriority = binaryOperator.getPriority(); - + if (binaryPriority > maxPriority) { maxPriority = binaryPriority; maxPriorityPosition = i; @@ -742,7 +740,7 @@ public final class ExpressionParser<T> { final PriorityBiFunction<T, UncertainDouble, T> numericOperator = this.numericOperators .get(components.get(i)); final int numericPriority = numericOperator.getPriority(); - + if (numericPriority > maxPriority) { maxPriority = numericPriority; maxPriorityPosition = i; @@ -752,11 +750,11 @@ public final class ExpressionParser<T> { break; } } - + // max priority position found return maxPriorityPosition; } - + /** * Determines whether an inputted string is an object or an operator * @@ -768,7 +766,7 @@ public final class ExpressionParser<T> { */ 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)) @@ -778,7 +776,7 @@ public final class ExpressionParser<T> { else return TokenType.OBJECT; } - + /** * Parses an expression. * @@ -792,7 +790,7 @@ public final class ExpressionParser<T> { return this.parseReversePolishExpression( this.convertExpressionToReversePolish(expression)); } - + /** * Parses an expression expressed in reverse Polish notation. * @@ -804,43 +802,43 @@ public final class ExpressionParser<T> { */ T parseReversePolishExpression(final String expression) { Objects.requireNonNull(expression, "expression must not be null."); - + final Deque<T> stack = new ArrayDeque<>(); final Deque<UncertainDouble> doubleStack = 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(o2, o1)); break; - + case NUMERIC_OPERATOR: if (stack.size() < 1 || doubleStack.size() < 1) throw new IllegalStateException(String.format( "Attempted to call binary operator %s with insufficient arguments.", item)); - + final T ot = stack.pop(); final UncertainDouble on = doubleStack.pop(); final BiFunction<T, UncertainDouble, T> op = this.numericOperators .get(item); stack.push(op.apply(ot, on)); break; - + case OBJECT: // just add it to the stack // these try-catch statements are necessary @@ -849,41 +847,41 @@ public final class ExpressionParser<T> { // that's the only way to tell if an expression is a number or not. try { stack.push(this.objectObtainer.apply(item)); - } catch (Exception e) { + } catch (final Exception e) { try { doubleStack.push(UncertainDouble.fromString(item)); - } catch (IllegalArgumentException e2) { + } catch (final IllegalArgumentException e2) { try { doubleStack.push( UncertainDouble.of(Double.parseDouble(item), 0)); - } catch (NumberFormatException e3) { + } catch (final NumberFormatException e3) { throw e; } } } 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( |