From b0d27faf67ec23b3d55786e00d4fd3b0d07567ee Mon Sep 17 00:00:00 2001 From: bjculkin Date: Thu, 23 Mar 2017 10:46:02 -0400 Subject: Add forgetful groups. Forgetful groups are groups which reset the currently allowed nested openers/closers from enclosing groups. This is useful for things like quoted strings, where you don't want groups to open inside them. As a consequence, this also adds nested openers. However, predicated openers/closers cannot be nested. --- .../parserutils/delims/SequenceDelimiter.java | 81 ++++++++++++++++++---- 1 file changed, 68 insertions(+), 13 deletions(-) (limited to 'BJC-Utils2/src/main/java/bjc/utils/parserutils/delims/SequenceDelimiter.java') diff --git a/BJC-Utils2/src/main/java/bjc/utils/parserutils/delims/SequenceDelimiter.java b/BJC-Utils2/src/main/java/bjc/utils/parserutils/delims/SequenceDelimiter.java index dee5034..e723123 100644 --- a/BJC-Utils2/src/main/java/bjc/utils/parserutils/delims/SequenceDelimiter.java +++ b/BJC-Utils2/src/main/java/bjc/utils/parserutils/delims/SequenceDelimiter.java @@ -9,11 +9,14 @@ import bjc.utils.esodata.Stack; import bjc.utils.funcdata.IMap; import bjc.utils.funcutils.StringUtils; +import com.google.common.collect.HashMultimap; import com.google.common.collect.HashMultiset; +import com.google.common.collect.Multimap; import com.google.common.collect.Multiset; import java.util.HashMap; import java.util.Map; +import java.util.Map.Entry; /** * Convert linear sequences into trees that represent group structure. @@ -24,10 +27,6 @@ import java.util.Map; * The type of items in the sequence. */ public class SequenceDelimiter { - /* - * Mapping from opening delimiters to the names of the groups they open - */ - /* * Mapping from group names to actual groups. */ @@ -47,7 +46,7 @@ public class SequenceDelimiter { * structure. * * Essentially, creates a parse tree of the expression against the - * following grammar while obeying the defined group rules. + * following grammar while obeying the defined grouping rules. * * 
 	 *              -> ( |  | )*
@@ -95,6 +94,8 @@ public class SequenceDelimiter {
 			throws DelimiterException {
 		if(initialGroup == null) {
 			throw new NullPointerException("Initial group must be specified.");
+		} else if(chars == null) {
+			throw new NullPointerException("Sequence characteristics must not be null");
 		}
 
 		/*
@@ -106,11 +107,18 @@ public class SequenceDelimiter {
 		 * Open initial group.
 		 */
 		groupStack.push(initialGroup.open(chars.root, null));
-		
+
 		/*
 		 * Groups that aren't allowed to be opened at the moment.
 		 */
-		Multiset forbiddenDelimiters = HashMultiset.create();
+		Stack> forbiddenDelimiters = new SimpleStack<>();
+		forbiddenDelimiters.push(HashMultiset.create());
+
+		/*
+		 * Groups that are allowed to be opened at the moment.
+		 */
+		Stack> allowedDelimiters = new SimpleStack<>();
+		allowedDelimiters.push(HashMultimap.create());
 
 		/*
 		 * Map of who forbid what for debugging purposes.
@@ -122,7 +130,19 @@ public class SequenceDelimiter {
 
 			IPair possibleOpenPar = groupStack.top().doesOpen(tok);
 			T possibleOpen = possibleOpenPar.getLeft();
-			
+
+			if(possibleOpen == null) {
+				/*
+				 * Handle nested openers.
+				 * 
+				 * Local openers take priority over nested ones
+				 * if they overlap.
+				 */
+				if(allowedDelimiters.top().containsKey(tok)) {
+					possibleOpen = allowedDelimiters.top().get(tok).iterator().next();
+				}
+			}
+
 			/*
 			 * If we have an opening delimiter, handle it.
 			 */
@@ -167,11 +187,28 @@ public class SequenceDelimiter {
 				DelimiterGroup.OpenGroup open = group.open(tok, possibleOpenPar.getRight());
 				groupStack.push(open);
 
+				/*
+				 * Handle 'forgetful' groups that reset nesting
+				 */
+				if(open.isForgetful()) {
+					allowedDelimiters.push(HashMultimap.create());
+					forbiddenDelimiters.push(HashMultiset.create());
+				}
+
+				/*
+				 * Add the nested opens from this group.
+				 */
+				Multimap currentAllowed = allowedDelimiters.top();
+				for(Entry opener : open.getNestingOpeners().entrySet()) {
+					currentAllowed.put(opener.getKey(), opener.getValue());
+				}
+
 				/*
 				 * Add the nested exclusions from this group
 				 */
+				Multiset currentForbidden = forbiddenDelimiters.top();
 				for(T exclusion : open.getNestingExclusions()) {
-					forbiddenDelimiters.add(exclusion);
+					currentForbidden.add(exclusion);
 
 					whoForbid.put(exclusion, possibleOpen);
 				}
@@ -186,11 +223,28 @@ public class SequenceDelimiter {
 				/*
 				 * Remove nested exclusions from this group.
 				 */
+				Multiset currentForbidden = forbiddenDelimiters.top();
 				for(T excludedGroup : closed.getNestingExclusions()) {
-					forbiddenDelimiters.remove(excludedGroup);
+					currentForbidden.remove(excludedGroup);
 
 					whoForbid.remove(excludedGroup);
 				}
+
+				/*
+				 * Remove the nested opens from this group.
+				 */
+				Multimap currentAllowed = allowedDelimiters.top();
+				for(Entry closer : closed.getNestingOpeners().entrySet()) {
+					currentAllowed.remove(closer.getKey(), closer.getValue());
+				}
+
+				/*
+				 * Handle 'forgetful' groups that reset nesting.
+				 */
+				if(closed.isForgetful()) {
+					allowedDelimiters.drop();
+					forbiddenDelimiters.drop();
+				}
 			} else if(!groupStack.empty() && groupStack.top().marksSubgroup(tok)) {
 				groupStack.top().markSubgroup(tok, chars);
 			} else {
@@ -223,15 +277,16 @@ public class SequenceDelimiter {
 		return groupStack.pop().toTree(chars.root, chars);
 	}
 
-	private boolean isForbidden(Stack.OpenGroup> groupStack, Multiset forbiddenDelimiters,
-			T groupName) {
+	private boolean isForbidden(Stack.OpenGroup> groupStack,
+			Stack> forbiddenDelimiters, T groupName) {
 		boolean localForbid;
+
 		if(groupStack.empty())
 			localForbid = false;
 		else
 			localForbid = groupStack.top().excludes(groupName);
 
-		return localForbid || forbiddenDelimiters.contains(groupName);
+		return localForbid || forbiddenDelimiters.top().contains(groupName);
 	}
 
 	/**
-- 
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