add isTrue message to PythonObjectLibrary

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/DefaultPythonBooleanExports.java

@@ -76,4 +76,9 @@ static LazyPythonClass getLazyPythonClass(@SuppressWarnings("unused") Boolean va
     static long hash(Boolean value) {
         return value ? 1 : 0;
     }
+
+    @ExportMessage
+    static boolean isTrue(Boolean value) {
+        return value;
+    }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/DefaultPythonDoubleExports.java

@@ -74,4 +74,9 @@ static long hashDoubleWithDecimals(Double self) {
             return self.hashCode();
         }
     }
+
+    @ExportMessage
+    static boolean isTrue(Double value) {
+        return value != 0.0;
+    }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/DefaultPythonIntegerExports.java

@@ -76,4 +76,9 @@ static LazyPythonClass getLazyPythonClass(@SuppressWarnings("unused") Integer va
     static long hash(Integer value) {
         return value;
     }
+
+    @ExportMessage
+    static boolean isTrue(Integer value) {
+        return value != 0;
+    }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/DefaultPythonLongExports.java

@@ -93,4 +93,9 @@ static LazyPythonClass getLazyPythonClass(@SuppressWarnings("unused") Long value
     static long hash(Long value) {
         return value;
     }
+
+    @ExportMessage
+    static boolean isTrue(Long value) {
+        return value != 0;
+    }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/DefaultPythonObjectExports.java

@@ -47,6 +47,7 @@
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Cached.Shared;
+import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.interop.InteropLibrary;
 import com.oracle.truffle.api.interop.UnsupportedMessageException;
 import com.oracle.truffle.api.library.CachedLibrary;
@@ -138,4 +139,61 @@ static int length(Object receiver,
             throw raise.raiseHasNoLength(receiver);
         }
     }
+
+
+    @ExportMessage
+    static class IsTrue {
+        @Specialization(guards = "lib.isBoolean(receiver)")
+        static boolean bool(Object receiver,
+                        @CachedLibrary("receiver") InteropLibrary lib) {
+            try {
+                return lib.asBoolean(receiver);
+            } catch (UnsupportedMessageException e) {
+                CompilerDirectives.transferToInterpreter();
+                throw new IllegalStateException(e);
+            }
+        }
+
+        @Specialization(guards = "lib.fitsInLong(receiver)")
+        static boolean integer(Object receiver,
+                        @CachedLibrary("receiver") InteropLibrary lib) {
+            try {
+                return lib.asLong(receiver) != 0;
+            } catch (UnsupportedMessageException e) {
+                CompilerDirectives.transferToInterpreter();
+                throw new IllegalStateException(e);
+            }
+        }
+
+        @Specialization(guards = "lib.fitsInDouble(receiver)")
+        static boolean floatingPoint(Object receiver,
+                        @CachedLibrary("receiver") InteropLibrary lib) {
+            try {
+                return lib.asDouble(receiver) != 0.0;
+            } catch (UnsupportedMessageException e) {
+                CompilerDirectives.transferToInterpreter();
+                throw new IllegalStateException(e);
+            }
+        }
+
+        @Specialization(guards = "lib.hasArrayElements(receiver)")
+        static boolean array(Object receiver,
+                        @CachedLibrary("receiver") InteropLibrary lib) {
+            try {
+                return lib.getArraySize(receiver) > 0;
+            } catch (UnsupportedMessageException e) {
+                CompilerDirectives.transferToInterpreter();
+                throw new IllegalStateException(e);
+            }
+        }
+
+        @Specialization(guards = {
+                            "!lib.isBoolean(receiver)", "!lib.fitsInLong(receiver)",
+                            "!lib.fitsInDouble(receiver)", "!lib.hasArrayElements(receiver)"
+        })
+        static boolean generic(Object receiver,
+                        @CachedLibrary("receiver") InteropLibrary lib) {
+            return !lib.isNull(receiver);
+        }
+    }
 }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/PythonObjectLibrary.java

@@ -321,6 +321,26 @@ public boolean isSequence(Object receiver) {
         return false;
     }
 
+    /**
+     * Checks wether this object should be interpreted as {@code
+     * true}-ish. Mimics the coercion behaviour of {@code PyObject_IsTrue}, and
+     * thus uses both {@code slot_nb_bool} coercion and {@link #length}/{@link
+     * #lengthWithState}.
+     */
+    public boolean isTrueWithState(Object receiver, ThreadState state) {
+        if (state == null) {
+            return true;
+        }
+        return isTrue(receiver);
+    }
+
+    /**
+     * @see #isTrueWithState
+     */
+    public boolean isTrue(Object receiver) {
+        return isTrueWithState(receiver, null);
+    }
+
     /**
      * Implements the logic from {@code PyObject_Size} (to which {@code
      * PySequence_Length} is an alias). The logic which is to try a) {@code