next() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/1-parse/state/tag.js lines 431–542

function next(parser) {
	const start = parser.index - 1;

	const block = parser.current(); // TODO type should not be TemplateNode, that's much too broad

	if (block.type === 'IfBlock') {
		if (!parser.eat('else')) e.expected_token(start, '{:else} or {:else if}');
		if (parser.eat('if')) e.block_invalid_elseif(start);

		parser.allow_whitespace();

		parser.fragments.pop();

		block.alternate = create_fragment();
		parser.fragments.push(block.alternate);

		// :else if
		if (parser.eat('if')) {
			parser.require_whitespace();

			const expression = read_expression(parser);

			parser.allow_whitespace();
			parser.eat('}', true);

			let elseif_start = start - 1;
			while (parser.template[elseif_start] !== '{') elseif_start -= 1;

			/** @type {AST.IfBlock} */
			const child = parser.append({
				start: elseif_start,
				end: -1,
				type: 'IfBlock',
				elseif: true,
				test: expression,
				consequent: create_fragment(),
				alternate: null,
				metadata: {
					expression: new ExpressionMetadata()
				}
			});

			parser.stack.push(child);
			parser.fragments.pop();
			parser.fragments.push(child.consequent);
		} else {
			// :else
			parser.allow_whitespace();
			parser.eat('}', true);
		}

		return;
	}

	if (block.type === 'EachBlock') {
		if (!parser.eat('else')) e.expected_token(start, '{:else}');

		parser.allow_whitespace();
		parser.eat('}', true);

		block.fallback = create_fragment();

		parser.fragments.pop();
		parser.fragments.push(block.fallback);

		return;
	}

	if (block.type === 'AwaitBlock') {
		if (parser.eat('then')) {
			if (block.then) {
				e.block_duplicate_clause(start, '{:then}');
			}

			if (!parser.eat('}')) {
				parser.require_whitespace();
				block.value = read_pattern(parser);
				parser.allow_whitespace();
				parser.eat('}', true);
			}