IntegerChecker.java

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//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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package org.apache.doris.nereids.trees.expressions.literal.format;

/** IntegerChecker */
public class IntegerChecker extends FormatChecker {
    private static final IntegerChecker INSTANCE = new IntegerChecker();

    private final FormatChecker checker;

    private IntegerChecker() {
        super("IntegerChecker");
        checker = and(
            option(chars(c -> c == '+' || c == '-')),
            digit(1)
        );
    }

    public static boolean isValidInteger(String string) {
        StringInspect stringInspect = new StringInspect(string);
        return INSTANCE.check(stringInspect).matched && stringInspect.eos();
    }

    @Override
    protected boolean doCheck(StringInspect stringInspect) {
        return checker.check(stringInspect).matched;
    }
}