X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=blobdiff_plain;f=bundles%2Forg.simantics.scl.compiler%2Fsrc%2Forg%2Fsimantics%2Fscl%2Fcompiler%2Fenvironment%2Ffilter%2FNamespaceFilters.java;fp=bundles%2Forg.simantics.scl.compiler%2Fsrc%2Forg%2Fsimantics%2Fscl%2Fcompiler%2Fenvironment%2Ffilter%2FNamespaceFilters.java;h=57159b861d7d42254266dda514db36410137157f;hp=0000000000000000000000000000000000000000;hb=969bd23cab98a79ca9101af33334000879fb60c5;hpb=866dba5cd5a3929bbeae85991796acb212338a08

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/environment/filter/NamespaceFilters.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/environment/filter/NamespaceFilters.java
new file mode 100644
index 000000000..57159b861
--- /dev/null
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/environment/filter/NamespaceFilters.java
@@ -0,0 +1,128 @@
+package org.simantics.scl.compiler.environment.filter;
+
+import gnu.trove.set.hash.THashSet;
+
+import org.simantics.scl.compiler.elaboration.expressions.EVar;
+import org.simantics.scl.compiler.module.ImportDeclaration.ImportSpec;
+
+public class NamespaceFilters {
+    public static NamespaceFilter createFromSpec(ImportSpec spec) {
+        if(spec.hiding) {
+            if(spec.values.length == 0)
+                return AcceptAllNamespaceFilter.INSTANCE;
+            THashSet<String> names = new THashSet<String>(spec.values.length);
+            for(EVar value : spec.values)
+                names.add(value.name);
+            return new NegativeNamespaceFilter(names);
+        }
+        else {
+            THashSet<String> names = new THashSet<String>(spec.values.length);
+            for(EVar value : spec.values)
+                names.add(value.name);
+            return new PositiveNamespaceFilter(names);
+        }
+    }
+    
+    public static NamespaceFilter union(NamespaceFilter a, NamespaceFilter b) {
+        if(a == AcceptAllNamespaceFilter.INSTANCE || b == AcceptAllNamespaceFilter.INSTANCE)
+            return AcceptAllNamespaceFilter.INSTANCE;
+        if(a instanceof PositiveNamespaceFilter) {
+            if(b instanceof PositiveNamespaceFilter)
+                return unionImpl((PositiveNamespaceFilter)a, (PositiveNamespaceFilter)b);
+            else if(b instanceof NegativeNamespaceFilter)
+                return unionImpl((NegativeNamespaceFilter)b, (PositiveNamespaceFilter)a);
+        }
+        else if(a instanceof NegativeNamespaceFilter) {
+            if(b instanceof PositiveNamespaceFilter)
+                return unionImpl((NegativeNamespaceFilter)a, (PositiveNamespaceFilter)b);
+            else if(b instanceof NegativeNamespaceFilter)
+                return unionImpl((NegativeNamespaceFilter)a, (NegativeNamespaceFilter)b);
+        }
+        return new NamespaceFilterUnion(a, b);
+    }
+    
+    private static NamespaceFilter unionImpl(PositiveNamespaceFilter a, PositiveNamespaceFilter b) {
+        THashSet<String> includedValues = new THashSet<String>(a.includedValues.size() + b.includedValues.size());
+        includedValues.addAll(a.includedValues);
+        includedValues.addAll(b.includedValues);
+        if(includedValues.size() == a.includedValues.size())
+            return a;
+        if(includedValues.size() == b.includedValues.size())
+            return b;
+        return new PositiveNamespaceFilter(includedValues);
+    }
+    
+    private static NamespaceFilter unionImpl(NegativeNamespaceFilter a, PositiveNamespaceFilter b) {
+        THashSet<String> excludedValues = new THashSet<String>(a.excludedValues);
+        excludedValues.removeAll(b.includedValues);
+        if(excludedValues.size() == a.excludedValues.size())
+            return a;
+        if(excludedValues.isEmpty())
+            return AcceptAllNamespaceFilter.INSTANCE;
+        return new NegativeNamespaceFilter(excludedValues);
+    }
+    
+    private static NamespaceFilter unionImpl(NegativeNamespaceFilter a, NegativeNamespaceFilter b) {
+        THashSet<String> excludedValues = new THashSet<String>(a.excludedValues);
+        excludedValues.retainAll(b.excludedValues);
+        if(excludedValues.size() == a.excludedValues.size())
+            return a;
+        if(excludedValues.size() == b.excludedValues.size())
+            return b;
+        if(excludedValues.isEmpty())
+            return AcceptAllNamespaceFilter.INSTANCE;
+        return new NegativeNamespaceFilter(excludedValues);
+    }
+    
+    public static NamespaceFilter intersection(NamespaceFilter a, NamespaceFilter b) {
+        if(a == AcceptAllNamespaceFilter.INSTANCE)
+            return b;
+        if(b == AcceptAllNamespaceFilter.INSTANCE)
+            return a;
+        if(a instanceof PositiveNamespaceFilter) {
+            if(b instanceof PositiveNamespaceFilter)
+                return intersectionImpl((PositiveNamespaceFilter)a, (PositiveNamespaceFilter)b);
+            else if(b instanceof NegativeNamespaceFilter)
+                return intersectionImpl((PositiveNamespaceFilter)a, (NegativeNamespaceFilter)b);
+        }
+        else if(a instanceof NegativeNamespaceFilter) {
+            if(b instanceof PositiveNamespaceFilter)
+                return intersectionImpl((PositiveNamespaceFilter)b, (NegativeNamespaceFilter)a);
+            else if(b instanceof NegativeNamespaceFilter)
+                return intersectionImpl((NegativeNamespaceFilter)a, (NegativeNamespaceFilter)b);
+        }
+        return new NamespaceFilterIntersection(a, b);
+    }
+
+    private static NamespaceFilter intersectionImpl(NegativeNamespaceFilter a,
+            NegativeNamespaceFilter b) {
+        THashSet<String> excludedValues = new THashSet<String>(a.excludedValues.size() + b.excludedValues.size());
+        excludedValues.addAll(a.excludedValues);
+        excludedValues.addAll(b.excludedValues);
+        if(excludedValues.size() == a.excludedValues.size())
+            return a;
+        if(excludedValues.size() == b.excludedValues.size())
+            return b;
+        return new NegativeNamespaceFilter(excludedValues);
+    }
+
+    private static NamespaceFilter intersectionImpl(PositiveNamespaceFilter a,
+            NegativeNamespaceFilter b) {
+        THashSet<String> includedValues = new THashSet<String>(a.includedValues);
+        includedValues.removeAll(b.excludedValues);
+        if(includedValues.size() == a.includedValues.size())
+            return a;
+        return new PositiveNamespaceFilter(includedValues);
+    }
+
+    private static NamespaceFilter intersectionImpl(PositiveNamespaceFilter a,
+            PositiveNamespaceFilter b) {
+        THashSet<String> includedValues = new THashSet<String>(a.includedValues);
+        includedValues.retainAll(b.includedValues);
+        if(includedValues.size() == a.includedValues.size())
+            return a;
+        if(includedValues.size() == b.includedValues.size())
+            return b;
+        return new PositiveNamespaceFilter(includedValues);
+    }
+}