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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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package com.oracle.graal.python.lib;

import com.oracle.graal.python.builtins.PythonBuiltinClassType;
import com.oracle.graal.python.builtins.objects.PNone;
import com.oracle.graal.python.builtins.objects.PythonAbstractObject;
import com.oracle.graal.python.builtins.objects.type.SpecialMethodSlot;
import com.oracle.graal.python.nodes.PNodeWithContext;
import com.oracle.graal.python.nodes.attributes.LookupCallableSlotInMRONode;
import com.oracle.graal.python.nodes.object.GetClassNode;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.GenerateUncached;
import com.oracle.truffle.api.dsl.ImportStatic;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.interop.InteropLibrary;
import com.oracle.truffle.api.library.CachedLibrary;
import com.oracle.truffle.api.strings.TruffleString;

/**
 * Checks whether a value can be converted to {@code double} using {@link PyFloatAsDoubleNode} o
 * {@link PyNumberFloatNode}. There is no direct CPython function equivalent, as CPython typically
 * checks for the {@code nb_float} and {@code nb_index} slots directly.
 */
@GenerateUncached
@ImportStatic(SpecialMethodSlot.class)
public abstract class CanBeDoubleNode extends PNodeWithContext {
    public abstract boolean execute(Object object);

    @Specialization
    static boolean doDouble(@SuppressWarnings("unused") Double object) {
        return true;
    }

    @Specialization
    static boolean doInt(@SuppressWarnings("unused") Integer object) {
        return true;
    }

    @Specialization
    static boolean doLong(@SuppressWarnings("unused") Long object) {
        return true;
    }

    @Specialization
    static boolean doPythonObject(PythonAbstractObject object,
                    @Cached GetClassNode getClassNode,
                    @Cached(parameters = "Float") LookupCallableSlotInMRONode lookupFloat,
                    @Cached(parameters = "Index") LookupCallableSlotInMRONode lookupIndex) {
        Object type = getClassNode.execute(object);
        return lookupFloat.execute(type) != PNone.NO_VALUE || lookupIndex.execute(type) != PNone.NO_VALUE;
    }

    @Specialization
    static boolean doBoolean(@SuppressWarnings("unused") Boolean object) {
        return true;
    }

    @Specialization
    static boolean doString(@SuppressWarnings("unused") TruffleString object) {
        return false;
    }

    @Specialization
    static boolean doPBCT(@SuppressWarnings("unused") PythonBuiltinClassType object) {
        return false;
    }

    @Specialization(replaces = "doPythonObject")
    static boolean doGeneric(Object object,
                    @CachedLibrary(limit = "3") InteropLibrary interopLibrary,
                    @Cached(parameters = "Float") LookupCallableSlotInMRONode lookupFloat,
                    @Cached(parameters = "Index") LookupCallableSlotInMRONode lookupIndex,
                    @Cached GetClassNode getClassNode) {
        Object type = getClassNode.execute(object);
        if (type == PythonBuiltinClassType.ForeignObject) {
            return interopLibrary.fitsInDouble(object) || interopLibrary.fitsInLong(object) || interopLibrary.isBoolean(object);
        }
        return lookupFloat.execute(type) != PNone.NO_VALUE || lookupIndex.execute(type) != PNone.NO_VALUE;
    }

    public static CanBeDoubleNode create() {
        return CanBeDoubleNodeGen.create();
    }
}
