org.apache.sling.scripting.sightly.compiler.expression.nodes.NumericConstant Maven / Gradle / Ivy

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package org.apache.sling.scripting.sightly.compiler.expression.nodes;

import org.apache.sling.scripting.sightly.compiler.expression.NodeVisitor;

/**
 * Defines a numeric constant expression (e.g. "42.1").
 */
public final class NumericConstant implements Atom {

    public static final NumericConstant ZERO = new NumericConstant(0);
    public static final NumericConstant ONE = new NumericConstant(1);
    public static final NumericConstant TWO = new NumericConstant(2);

    private final String text;
    private final Number value;

    /**
     * Creates a numeric constant.
     *
     * @param text the text representation
     * @throws java.lang.NumberFormatException if the text is not in a numeric format
     */
    public NumericConstant(String text) {
        this.text = text;
        this.value = parseNumber(text);
    }

    /**
     * Creates a numeric constant based on a {@link Number} representation.
     *
     * @param value the number representation
     */
    public NumericConstant(Number value) {
        this.value = value;
        this.text = value.toString();
    }

    /**
     * Returns the number representation of this constant.
     *
     * @return the number representation of this constant
     */
    public Number getValue() {
        return value;
    }

    @Override
    public String getText() {
        return text;
    }

    @Override
    public  T accept(NodeVisitor visitor) {
        return visitor.evaluate(this);
    }

    @Override
    public String toString() {
        return "NumericConstant{" +
                "text='" + text + '\'' +
                '}';
    }

    private Number parseNumber(String s) {
        if (s.contains(".") || s.contains("e") || s.contains("E")) {
            double interim = Double.parseDouble(s);
            if (interim == 0) {
                return 0.0;
            }
            return interim;
        }
        return Long.parseLong(s);
    }

}