Moved SCL parser generator to platform repository.

[simantics/platform.git] / bundles / org.simantics.scl.compiler / src / org / simantics / scl / compiler / parser / generator / table / ItemSet.java

diff --git a/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/parser/generator/table/ItemSet.java b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/parser/generator/table/ItemSet.java
new file mode 100644 (file)
index 0000000..0b82409
--- /dev/null
+++ b/bundles/org.simantics.scl.compiler/src/org/simantics/scl/compiler/parser/generator/table/ItemSet.java
@@ -0,0 +1,61 @@
+package org.simantics.scl.compiler.parser.generator.table;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import org.simantics.scl.compiler.parser.generator.grammar.AnaGrammar;
+
+public class ItemSet {
+    public final Item[] items;
+    int hash;
+
+    public ItemSet(Item[] items) {
+        this.items = items;
+        Arrays.sort(items);
+    }
+    
+    public ItemSet(Collection<Item> items) {
+        this(items.toArray(new Item[items.size()]));
+    }
+    
+    private static final int PROD = 31*31;
+    
+    @Override
+    public int hashCode() {
+        if(hash == 0) {
+            int h = 1;
+            for(Item item : items)
+                h = PROD*h + item.hashCode();
+            hash = h;
+        }
+        return hash;
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+        if(this == obj)
+            return true;
+        if(obj == null || obj.getClass() != getClass())
+            return false;
+        ItemSet other = (ItemSet)obj;
+        if(other.items.length != items.length)
+            return false;
+        for(int i=0;i<items.length;++i)
+            if(!items[i].equals(other.items[i]))
+                return false;
+        return true;
+    }
+    
+    public String toString(AnaGrammar grammar) {
+        StringBuilder b = new StringBuilder();
+            boolean first = true;
+        for(Item item : items) {
+            if(first)
+                first = false;
+            else
+                b.append('\n');
+            b.append("    ").append(item.toString(grammar));
+        }
+        return b.toString();
+    }
+}