Convert UnknownKeyException to KeyError, similar to Hash#fetch(missing_key)

* So we can know if the operation succeeded or not, and we map interop semantics more closely.

Author: eregon

src/main/java/org/truffleruby/core/exception/CoreExceptions.java

@@ -15,6 +15,7 @@
 import java.util.EnumSet;
 
 import com.oracle.truffle.api.interop.InvalidBufferOffsetException;
+import com.oracle.truffle.api.interop.UnknownKeyException;
 import org.jcodings.Encoding;
 import org.jcodings.specific.UTF8Encoding;
 import org.truffleruby.RubyContext;
@@ -404,11 +405,6 @@ public RubyException mathDomainError(String method, Node currentNode) {
 
     // IndexError
 
-    @TruffleBoundary
-    public RubyException indexErrorOutOfString(int index, Node currentNode) {
-        return indexError(StringUtils.format("index %d out of string", index), currentNode);
-    }
-
     @TruffleBoundary
     public RubyException indexError(String message, Node currentNode) {
         RubyClass exceptionClass = context.getCoreLibrary().indexErrorClass;
@@ -417,6 +413,11 @@ public RubyException indexError(String message, Node currentNode) {
         return ExceptionOperations.createRubyException(context, exceptionClass, errorMessage, currentNode, null);
     }
 
+    @TruffleBoundary
+    public RubyException indexErrorOutOfString(int index, Node currentNode) {
+        return indexError(StringUtils.format("index %d out of string", index), currentNode);
+    }
+
     @TruffleBoundary
     public RubyException indexTooSmallError(String type, int index, int length, Node currentNode) {
         return indexError(
@@ -445,6 +446,21 @@ public RubyException indexErrorInvalidBufferOffsetException(InvalidBufferOffsetE
         return indexError("invalid buffer offset " + exception.getByteOffset(), currentNode);
     }
 
+    // KeyError
+
+    @TruffleBoundary
+    public RubyException keyError(String message, Node currentNode) {
+        RubyClass exceptionClass = context.getCoreLibrary().keyErrorClass;
+        RubyString errorMessage = StringOperations
+                .createString(context, language, StringOperations.encodeRope(message, UTF8Encoding.INSTANCE));
+        return ExceptionOperations.createRubyException(context, exceptionClass, errorMessage, currentNode, null);
+    }
+
+    @TruffleBoundary
+    public RubyException keyError(UnknownKeyException exception, Node currentNode) {
+        return keyError(exception.getMessage(), currentNode);
+    }
+
     // StopIteration
 
     @TruffleBoundary

src/main/java/org/truffleruby/interop/InteropNodes.java

@@ -21,8 +21,6 @@
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.interop.ExceptionType;
 import com.oracle.truffle.api.interop.NodeLibrary;
-import com.oracle.truffle.api.interop.UnknownKeyException;
-import com.oracle.truffle.api.interop.UnsupportedTypeException;
 import org.jcodings.specific.UTF8Encoding;
 import org.truffleruby.RubyContext;
 import org.truffleruby.RubyLanguage;
@@ -2000,8 +1998,7 @@ protected Object getMetaQualifiedName(Object metaObject,
     }
     // endregion
 
-    // region Hash
-
+    // region Hash entries
     @CoreMethod(names = "has_hash_entries?", onSingleton = true, required = 1)
     public abstract static class HasHashEntriesNode extends InteropCoreMethodArrayArgumentsNode {
         @Specialization(limit = "getCacheLimit()")
@@ -2132,10 +2129,8 @@ protected Object readHashValue(Object receiver, Object key,
                 @Cached TranslateInteropExceptionNode translateInteropException) {
             try {
                 return interop.readHashValue(receiver, key);
-            } catch (UnsupportedMessageException e) {
+            } catch (InteropException e) {
                 throw translateInteropException.execute(e);
-            } catch (UnknownKeyException e) {
-                return nil;
             }
         }
     }
@@ -2163,10 +2158,8 @@ protected Object removeHashEntry(Object receiver, Object key,
             try {
                 interop.removeHashEntry(receiver, key);
                 return nil;
-            } catch (UnsupportedMessageException e) {
+            } catch (InteropException e) {
                 throw translateInteropException.execute(e);
-            } catch (UnknownKeyException e) {
-                return nil;
             }
         }
     }
@@ -2179,17 +2172,12 @@ protected Object writeHashEntry(Object receiver, Object key, Object value,
                 @Cached TranslateInteropExceptionNode translateInteropException) {
             try {
                 interop.writeHashEntry(receiver, key, value);
-                return nil;
-            } catch (UnsupportedMessageException e) {
-                throw translateInteropException.execute(e);
-            } catch (UnknownKeyException e) {
-                return nil;
-            } catch (UnsupportedTypeException e) {
+                return value;
+            } catch (InteropException e) {
                 throw translateInteropException.execute(e);
             }
         }
     }
-
     // endregion
 
     // region Identity

src/main/java/org/truffleruby/interop/TranslateInteropExceptionNode.java

@@ -11,6 +11,7 @@
 
 import com.oracle.truffle.api.interop.InvalidBufferOffsetException;
 import com.oracle.truffle.api.interop.StopIterationException;
+import com.oracle.truffle.api.interop.UnknownKeyException;
 import org.truffleruby.RubyContext;
 import org.truffleruby.RubyLanguage;
 import org.truffleruby.language.RubyBaseNode;
@@ -77,6 +78,13 @@ protected RuntimeException handle(
                 exception);
     }
 
+    @Specialization
+    protected RuntimeException handle(
+            UnknownKeyException exception, boolean inInvokeMember, Object receiver, Object[] args,
+            @CachedContext(RubyLanguage.class) RubyContext context) {
+        return new RaiseException(context, context.getCoreExceptions().keyError(exception, this), exception);
+    }
+
     @Specialization
     protected RuntimeException handle(
             UnknownIdentifierException exception, boolean inInvokeMember, Object receiver, Object[] args,