123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254 |
- /*
- * Copyright (c) 2006-2010 Chris Smith, Shane Mc Cormack, Gregory Holmes
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
- package com.dmdirc.addons.calc;
-
- import java.util.ArrayList;
- import java.util.List;
- import java.util.regex.Matcher;
- import java.util.regex.Pattern;
-
- /**
- * Describes the different types of possible token, their arities, precedence,
- * and the types of token that may follow them.
- *
- * @author chris
- */
- public enum TokenType {
-
- /** The start of an input string. */
- START(TokenTypeArity.HIDDEN, "^", 0, "NUMBER_*", "BRACKET_OPEN", "MOD_*"),
- /** The end of an input string. */
- END(TokenTypeArity.HIDDEN, "$", 0),
-
- /** An opening bracket. */
- BRACKET_OPEN(TokenTypeArity.NULLARY, "\\(", 0, "NUMBER_*", "MOD_*", "BRACKET_OPEN"),
- /** A closing bracket. */
- BRACKET_CLOSE(TokenTypeArity.NULLARY, "\\)", 50, "OP_*", "BRACKET_*", "END"),
-
- /** A floating point number. */
- NUMBER_FLOAT(TokenTypeArity.NULLARY, "[0-9]+\\.[0-9]+", 1, "OP_*", "BRACKET_*", "END") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return Float.valueOf(token.getToken().getContent());
- }
- },
-
- /** An integer. */
- NUMBER_INT(TokenTypeArity.NULLARY, "[0-9]+", 1, "OP_*", "BRACKET_*", "END") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return Float.valueOf(token.getToken().getContent());
- }
- },
-
- /** A modifier signalling the following number is positive. */
- MOD_POSITIVE(TokenTypeArity.UNARY, "\\+", 100, "NUMBER_*") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return token.getChildren().get(0).evaluate();
- }
- },
-
- /** A modifier signalling the following number is negative. */
- MOD_NEGATIVE(TokenTypeArity.UNARY, "-", 100, "NUMBER_*") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return -1 * token.getChildren().get(0).evaluate().floatValue();
- }
- },
-
- /** The addition operator. */
- OP_PLUS(TokenTypeArity.BINARY, "\\+", 7, "NUMBER_*", "BRACKET_OPEN") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return token.getChildren().get(0).evaluate().floatValue()
- + token.getChildren().get(1).evaluate().floatValue();
- }
- },
-
- /** The subtraction operator. */
- OP_MINUS(TokenTypeArity.BINARY, "-", 6, "NUMBER_*", "BRACKET_OPEN") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return token.getChildren().get(0).evaluate().floatValue()
- - token.getChildren().get(1).evaluate().floatValue();
- }
- },
-
- /** The multiplication operator. */
- OP_MULT(TokenTypeArity.BINARY, "(?=\\()|\\*", 9, "NUMBER_*", "BRACKET_OPEN") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return token.getChildren().get(0).evaluate().floatValue()
- * token.getChildren().get(1).evaluate().floatValue();
- }
- },
-
- /** The division operator. */
- OP_DIVIDE(TokenTypeArity.BINARY, "/", 10, "NUMBER_*", "BRACKET_OPEN") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return token.getChildren().get(0).evaluate().floatValue()
- / token.getChildren().get(1).evaluate().floatValue();
- }
- },
-
- /** The modulo operator. */
- OP_MOD(TokenTypeArity.BINARY, "%", 8, "NUMBER_*", "BRACKET_OPEN") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return token.getChildren().get(0).evaluate().floatValue()
- % token.getChildren().get(1).evaluate().floatValue();
- }
- },
-
- /** The power operator. */
- OP_POWER(TokenTypeArity.BINARY, "\\^", 11, "NUMBER_*", "BRACKET_OPEN") {
- /** {@inheritDoc} */
- @Override
- public Number evaluate(final TreeToken token) {
- return new Float(Math.pow(token.getChildren().get(0).evaluate().doubleValue(),
- token.getChildren().get(1).evaluate().doubleValue()));
- }
- },
- ;
-
- /** The string representation of tokens that may follow this one. */
- private final String[] strfollows;
- /** The precedence of this token. */
- private final int precedence;
- /** The list of tokens that may follow this one. */
- private List<TokenType> follows;
- /** The regular expression used to match this token. */
- private final Pattern regex;
- /** The arity of this token. */
- private final TokenTypeArity arity;
-
- /**
- * Creates a new token type with the specified arguments.
- *
- * @param arity The arity of this token
- * @param regex The regular expression used to match this token
- * @param precedence The precendence of this token
- * @param follows The names of the tokens which may follow this one
- */
- TokenType(final TokenTypeArity arity, final String regex,
- final int precedence, final String ... follows) {
- this.arity = arity;
- this.strfollows = follows;
- this.precedence = precedence;
- this.regex = Pattern.compile(regex);
- }
-
- /**
- * Retrieves a list of token types that may follow this one.
- *
- * @return A list of this token type's possible followers
- */
- public synchronized List<TokenType> getFollowers() {
- if (follows == null) {
- follows = new ArrayList<TokenType>();
-
- for (int i = 0; i < strfollows.length; i++) {
- follows.addAll(searchValueOf(strfollows[i]));
- }
- }
-
- return follows;
- }
-
- /**
- * Retrieves the arity of this token type.
- *
- * @return This token type's arity
- */
- public TokenTypeArity getArity() {
- return arity;
- }
-
- /**
- * Retrieves the precedence of this token type.
- *
- * @return This token type's precedence
- */
- public int getPrecedence() {
- return precedence;
- }
-
- /**
- * Attempts to match this token type against the specified input string
- * (starting at the specified offset).
- *
- * @param input The string to be matched
- * @param offset The offset within the string to start at
- * @return -1 if no match was made, otherwise the number of characters that
- * were matched as part of this token type.
- */
- public int match(final String input, final int offset) {
- final Matcher matcher = regex.matcher(input);
- matcher.useAnchoringBounds(false);
- matcher.useTransparentBounds(true);
-
- return matcher.find(offset) && matcher.start() == offset ? matcher.end() : -1;
- }
-
- /**
- * Evaluates the specified token of this token type into a number.
- *
- * @param token The token to be evaluated
- * @return A numerical representation of the specified token
- */
- public Number evaluate(final TreeToken token) {
- throw new AbstractMethodError("Can't evaluate this token type");
- }
-
- /**
- * Retrieves a list of types which match the specified name. The name
- * may end with an asterisk (*), which is treated as a wild card.
- *
- * @param name The name to be searched for
- * @return A list of matching tokens
- */
- protected static List<TokenType> searchValueOf(final String name) {
- final List<TokenType> res = new ArrayList<TokenType>();
-
- for (TokenType token : values()) {
- if ((name.endsWith("*")
- && token.name().startsWith(name.substring(0, name.length() - 1)))
- || name.equals(token.name())) {
- res.add(token);
- }
- }
-
- return res;
- }
- }
|