| // © 2018 and later: Unicode, Inc. and others. |
| // License & terms of use: http://www.unicode.org/copyright.html#License |
| package com.ibm.icu.impl.number.parse; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import com.ibm.icu.impl.StringSegment; |
| |
| /** |
| * Composes a number of matchers, running one after another. Matches the input string only if all of the |
| * matchers in the series succeed. Performs greedy matches within the context of the series. |
| * |
| * @author sffc |
| */ |
| public class SeriesMatcher implements NumberParseMatcher { |
| |
| protected List<NumberParseMatcher> matchers = null; |
| protected boolean frozen = false; |
| |
| public void addMatcher(NumberParseMatcher matcher) { |
| assert !frozen; |
| if (matchers == null) { |
| matchers = new ArrayList<NumberParseMatcher>(); |
| } |
| matchers.add(matcher); |
| } |
| |
| public void freeze() { |
| frozen = true; |
| } |
| |
| public int length() { |
| return matchers == null ? 0 : matchers.size(); |
| } |
| |
| @Override |
| public boolean match(StringSegment segment, ParsedNumber result) { |
| assert frozen; |
| if (matchers == null) { |
| return false; |
| } |
| |
| // TODO: Give a nice way to reset ParsedNumber to avoid the copy here. |
| ParsedNumber backup = new ParsedNumber(); |
| backup.copyFrom(result); |
| |
| int initialOffset = segment.getOffset(); |
| boolean maybeMore = true; |
| for (int i = 0; i < matchers.size();) { |
| NumberParseMatcher matcher = matchers.get(i); |
| int matcherOffset = segment.getOffset(); |
| if (segment.length() != 0) { |
| maybeMore = matcher.match(segment, result); |
| } else { |
| // Nothing for this matcher to match; ask for more. |
| maybeMore = true; |
| } |
| |
| boolean success = (segment.getOffset() != matcherOffset); |
| boolean isFlexible = matcher instanceof NumberParseMatcher.Flexible; |
| if (success && isFlexible) { |
| // Match succeeded, and this is a flexible matcher. Re-run it. |
| } else if (success) { |
| // Match succeeded, and this is NOT a flexible matcher. Proceed to the next matcher. |
| i++; |
| // Small hack: if there is another matcher coming, do not accept trailing weak chars. |
| // Needed for proper handling of currency spacing. |
| if (i < matchers.size() && segment.getOffset() != result.charEnd && result.charEnd > matcherOffset) { |
| segment.setOffset(result.charEnd); |
| } |
| } else if (isFlexible) { |
| // Match failed, and this is a flexible matcher. Try again with the next matcher. |
| i++; |
| } else { |
| // Match failed, and this is NOT a flexible matcher. Exit. |
| segment.setOffset(initialOffset); |
| result.copyFrom(backup); |
| return maybeMore; |
| } |
| } |
| |
| // All matchers in the series succeeded. |
| return maybeMore; |
| } |
| |
| @Override |
| public boolean smokeTest(StringSegment segment) { |
| assert frozen; |
| if (matchers == null) { |
| return false; |
| } |
| |
| // SeriesMatchers are never allowed to start with a Flexible matcher. |
| assert !(matchers.get(0) instanceof NumberParseMatcher.Flexible); |
| return matchers.get(0).smokeTest(segment); |
| } |
| |
| @Override |
| public void postProcess(ParsedNumber result) { |
| assert frozen; |
| if (matchers == null) { |
| return; |
| } |
| |
| for (int i = 0; i < matchers.size(); i++) { |
| NumberParseMatcher matcher = matchers.get(i); |
| matcher.postProcess(result); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "<SeriesMatcher " + matchers + ">"; |
| } |
| |
| } |