FoldLiteralArguments.java

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package org.apache.doris.nereids.trees.expressions.functions;

import org.apache.doris.nereids.trees.expressions.literal.Literal;

/**
 * Functions whose legality checks validate the value of some constant arguments.
 * The analyzer folds these arguments on FE before checkLegalityBeforeTypeCoercion,
 * so a constant expression such as 1 + 1 is validated like the literal it folds to.
 * A constant argument FE cannot fold is left to BE, unless FE needs its value to plan the function.
 */
public interface FoldLiteralArguments {
    /** whether the argument at the given index must be folded to a literal before the legality checks */
    boolean needFoldToLiteral(int index);

    /** whether the literal the argument at the given index folds to replaces the argument */
    default boolean acceptFoldedLiteral(int index, Literal folded) {
        return true;
    }
}