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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * The Universal Permissive License (UPL), Version 1.0
 *
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 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
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 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
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 * This license is subject to the following condition:
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 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
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package com.oracle.graal.python.lib;

import static com.oracle.graal.python.builtins.PythonBuiltinClassType.IndexError;
import static com.oracle.graal.python.builtins.PythonBuiltinClassType.TypeError;
import static com.oracle.graal.python.util.PythonUtils.TS_ENCODING;

import com.oracle.graal.python.builtins.objects.ints.PInt;
import com.oracle.graal.python.nodes.ErrorMessages;
import com.oracle.graal.python.nodes.PNodeWithContext;
import com.oracle.graal.python.nodes.PRaiseNode;
import com.oracle.graal.python.nodes.util.CannotCastException;
import com.oracle.graal.python.nodes.util.CastToTruffleStringNode;
import com.oracle.graal.python.util.OverflowException;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.GenerateUncached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.strings.TruffleString;

/**
 * Equivalent of CPython's {@code PyLong_AsDouble}. Converts an object into a Java double. Raises
 * {@code OverflowError} on overflow.
 */
@GenerateUncached
public abstract class PyUnicodeReadCharNode extends PNodeWithContext {
    public abstract int execute(Object object, long lindex);

    @Specialization
    int doGeneric(Object type, long lindex,
                    @Cached CastToTruffleStringNode castToStringNode,
                    @Cached TruffleString.CodePointLengthNode codePointLengthNode,
                    @Cached TruffleString.CodePointAtIndexNode codePointAtIndexNode,
                    @Cached PRaiseNode raiseNode) {
        try {
            TruffleString s = castToStringNode.execute(type);
            int index = PInt.intValueExact(lindex);
            // avoid StringIndexOutOfBoundsException
            if (index < 0 || index >= codePointLengthNode.execute(s, TS_ENCODING)) {
                throw raiseNode.raise(IndexError, ErrorMessages.STRING_INDEX_OUT_OF_RANGE);
            }
            return codePointAtIndexNode.execute(s, index, TS_ENCODING);
        } catch (CannotCastException e) {
            throw raiseNode.raise(TypeError, ErrorMessages.BAD_ARG_TYPE_FOR_BUILTIN_OP);
        } catch (OverflowException e) {
            throw raiseNode.raise(IndexError, ErrorMessages.STRING_INDEX_OUT_OF_RANGE);
        }
    }

    public static PyUnicodeReadCharNode create() {
        return PyUnicodeReadCharNodeGen.create();
    }
}
