java.js

// https://docs.oracle.com/javase/specs/jls/se15/html/jls-3.html#jls-3.10
var decimalDigits = '[0-9](_*[0-9])*';
var frac = `\\.(${decimalDigits})`;
var hexDigits = '[0-9a-fA-F](_*[0-9a-fA-F])*';
export var NUMERIC = {
  className: 'number',
  variants: [
    // DecimalFloatingPointLiteral
    // including ExponentPart
    { begin: `(\\b(${decimalDigits})((${frac})|\\.)?|(${frac}))` +
      `[eE][+-]?(${decimalDigits})[fFdD]?\\b` },
    // excluding ExponentPart
    { begin: `\\b(${decimalDigits})((${frac})[fFdD]?\\b|\\.([fFdD]\\b)?)` },
    { begin: `(${frac})[fFdD]?\\b` },
    { begin: `\\b(${decimalDigits})[fFdD]\\b` },

    // HexadecimalFloatingPointLiteral
    { begin: `\\b0[xX]((${hexDigits})\\.?|(${hexDigits})?\\.(${hexDigits}))` +
      `[pP][+-]?(${decimalDigits})[fFdD]?\\b` },

    // DecimalIntegerLiteral
    { begin: '\\b(0|[1-9](_*[0-9])*)[lL]?\\b' },

    // HexIntegerLiteral
    { begin: `\\b0[xX](${hexDigits})[lL]?\\b` },

    // OctalIntegerLiteral
    { begin: '\\b0(_*[0-7])*[lL]?\\b' },

    // BinaryIntegerLiteral
    { begin: '\\b0[bB][01](_*[01])*[lL]?\\b' },
  ],
  relevance: 0
};