Bring compiler into Astro (#4)

* include source compiler

* Import from JS

* Conditionally use the instance contents

Co-authored-by: Fred K. Schott <fkschott@gmail.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/src/compiler/parse/read/context.ts b/src/compiler/parse/read/context.ts
new file mode 100644
index 000000000..496d24bb1
--- /dev/null
+++ b/src/compiler/parse/read/context.ts
@@ -0,0 +1,84 @@
+// @ts-nocheck
+
+import { Parser } from '../index.js';
+import { isIdentifierStart } from 'acorn';
+import full_char_code_at from '../../utils/full_char_code_at.js';
+import {
+	is_bracket_open,
+	is_bracket_close,
+	is_bracket_pair,
+	get_bracket_close
+} from '../utils/bracket.js';
+import { parse_expression_at } from '../acorn.js';
+import { Pattern } from 'estree';
+
+export default function read_context(
+	parser: Parser
+): Pattern & { start: number; end: number } {
+	const start = parser.index;
+	let i = parser.index;
+
+	const code = full_char_code_at(parser.template, i);
+	if (isIdentifierStart(code, true)) {
+		return {
+			type: 'Identifier',
+			name: parser.read_identifier(),
+			start,
+			end: parser.index
+		};
+	}
+
+	if (!is_bracket_open(code)) {
+		parser.error({
+			code: 'unexpected-token',
+			message: 'Expected identifier or destructure pattern'
+		});
+	}
+
+	const bracket_stack = [code];
+	i += code <= 0xffff ? 1 : 2;
+
+	while (i < parser.template.length) {
+		const code = full_char_code_at(parser.template, i);
+		if (is_bracket_open(code)) {
+			bracket_stack.push(code);
+		} else if (is_bracket_close(code)) {
+			if (!is_bracket_pair(bracket_stack[bracket_stack.length - 1], code)) {
+				parser.error({
+					code: 'unexpected-token',
+					message: `Expected ${String.fromCharCode(
+						get_bracket_close(bracket_stack[bracket_stack.length - 1])
+					)}`
+				});
+			}
+			bracket_stack.pop();
+			if (bracket_stack.length === 0) {
+				i += code <= 0xffff ? 1 : 2;
+				break;
+			}
+		}
+		i += code <= 0xffff ? 1 : 2;
+	}
+
+	parser.index = i;
+
+	const pattern_string = parser.template.slice(start, i);
+	try {
+		// the length of the `space_with_newline` has to be start - 1
+		// because we added a `(` in front of the pattern_string,
+		// which shifted the entire string to right by 1
+		// so we offset it by removing 1 character in the `space_with_newline`
+		// to achieve that, we remove the 1st space encountered,
+		// so it will not affect the `column` of the node
+		let space_with_newline = parser.template.slice(0, start).replace(/[^\n]/g, ' ');
+		const first_space = space_with_newline.indexOf(' ');
+		space_with_newline = space_with_newline.slice(0, first_space) + space_with_newline.slice(first_space + 1);
+
+		return (parse_expression_at(
+			`${space_with_newline}(${pattern_string} = 1)`,
+			start - 1
+		) as any).left;
+	} catch (error) {
+		parser.acorn_error(error);
+	}
+}