Function consumeAToken

lib/css/syntax.js:1045–1092

* Per-character dispatcher. The outer loop has already advanced past * the lead code point (`pos - 1` is the lead). * @param {string} input input * @param {number} pos position just past the lead code point * @param {number} cc the lead code point (`input.charCodeAt(pos - 1)`, already read by th

(input, pos, cc, out)

 * @returns {MutableToken | undefined} the resulting token, or undefined at EOF
 */
function consumeAToken(input, pos, cc, out) {
	// `u` / `U` would start a unicode-range token in the spec; those are not
	// produced, so they map to HC_IDENT and fall through to ident-like.
	switch (cc < 128 ? _charClass[cc] : HC_IDENT) {
		// Run of whitespace → one <whitespace-token>.
		case HC_WHITESPACE:
			return consumeSpace(input, pos, out);
		// `"` / `'` → <string-token> (or <bad-string-token> on a raw newline).
		case HC_STRING:
			return consumeAStringToken(input, pos, out);
		// One-code-point token: its type is looked up in `_singleTT` (the `(` `)`
		// `,` `:` `;` `[` `]` `{` `}` set), so all of them share this arm.
		case HC_SINGLE:
			return fill(out, _singleTT[cc], pos - 1, pos);
		// `#` → <hash-token> if an ident/escape follows, else a <delim-token>.
		case HC_NUMBER_SIGN:
			return consumeNumberSign(input, pos, out);
		// `+` → <number-token> if it starts a number, else a <delim-token>.
		case HC_PLUS_SIGN:
			return consumePlusSign(input, pos, out);
		// `-` → number / <CDC-token> (`-->`) / ident / <delim-token>.
		case HC_HYPHEN_MINUS:
			return consumeHyphenMinus(input, pos, out);
		// `.` → <number-token> if a digit follows, else a <delim-token>.
		case HC_FULL_STOP:
			return consumeFullStop(input, pos, out);
		// `<` → <CDO-token> (`<!--`), else a <delim-token>.
		case HC_LESS_THAN:
			return consumeLessThan(input, pos, out);
		// `@` → <at-keyword-token> if an ident follows, else a <delim-token>.
		case HC_AT_SIGN:
			return consumeCommercialAt(input, pos, out);
		// `\` → ident-like token if it's a valid escape, else a <delim-token>.
		case HC_REVERSE_SOLIDUS:
			return consumeReverseSolidus(input, pos, out);
		// Digit → numeric token; `pos - 1` re-includes the digit the caller passed.
		case HC_DIGIT:
			return consumeANumericToken(input, pos - 1, out);
		// Ident-start (letter / `_` / non-ASCII, incl. `u`/`U`) → ident / function /
		// url token; `pos - 1` re-includes the lead code point.
		case HC_IDENT:
			return consumeAnIdentLikeToken(input, pos - 1, out);
		default:
			// HC_DELIM. EOF is impossible here (caller guarded with the outer
			// loop's `pos < input.length` check). Anything else: a <delim-token>.
			return fill(out, TT_DELIM, pos - 1, pos);
	}
}

/**
 * Read one raw token (comment / whitespace / value token) starting at byte