Resolve space properly

Author: dy

feature/if.js

@@ -11,12 +11,11 @@ export const block = () =>
 export const body = () =>
   space() !== 123 ? expr(STATEMENT + .5) : (skip(), expr(STATEMENT - .5, 125) || null);
 
-// Check for `else` after optional semicolon (use parse.space to consume comments)
+// Check for `else` after optional semicolon
 const checkElse = () => {
   const from = idx;
-  const sp = parse.space || space;
-  if (sp() === SEMI) skip();
-  sp();
+  if (space() === SEMI) skip();
+  space();
   if (word('else')) return skip(4), true;
   return seek(from), false;
 };

parse.js

@@ -51,13 +51,13 @@ export let idx, cur,
       )
     ) token = newNode;
 
-    if (end) cc == end ? idx++ : err('Unclosed ' + String.fromCharCode(end - (end > 42 ? 2 : 1)));
+    if (end) cc == end ? (idx++, end === 125 && parse.asi && (parse.newline = true)) : err('Unclosed ' + String.fromCharCode(end - (end > 42 ? 2 : 1)));
 
     return token;
   },
 
   // skip space chars, return first non-space character
-  space = parse.space = (cc, from = idx) => {
+  space = (cc, from = idx) => {
     while ((cc = cur.charCodeAt(idx)) <= SPACE) {
       if (parse.asi && cc === 10) parse.newline = true
       idx++
@@ -143,6 +143,14 @@ export let idx, cur,
       (seek(idx + l), (r = map()) ? loc(r, from) : seek(from), r) ||
       prev?.(a, curPrec, curOp);
 
+// Keep parse.space overrides in sync with the exported binding used by features.
+Object.defineProperty(parse, 'space', {
+  configurable: true,
+  enumerable: true,
+  get: () => space,
+  set: fn => (space = fn)
+});
+
 // === Compile: AST → Evaluator ===
 
 

test/feature/async-class.js

@@ -110,6 +110,11 @@ test('numbers: bigint', () => {
   is(parse('123n'), [, 123n]);
   is(parse('1_000n'), [, 1000n]);
   is(parse('0n'), [, 0n]);
+  // prefixed bigint
+  is(parse('0xFFn'), [, 0xFFn]);
+  is(parse('0o77n'), [, 0o77n]);
+  is(parse('0b101n'), [, 0b101n]);
+  is(parse('0x1_ABCn'), [, 0x1ABCn]);
 });
 
 test('meta: import.meta', () => {

test/justin.js

@@ -3,7 +3,7 @@
 
 import test, { is, throws } from 'tst'
 import { parse, nary, binary, unary } from '../justin.js'
-import { compile, operator } from '../parse.js'
+import { compile, operator, cur, idx, seek } from '../parse.js'
 
 const justin = s => compile(parse(s))
 
@@ -121,6 +121,27 @@ test('justin: optional chaining', () => {
   is(justin('a?.b?.(arg)?.[c] ?. d')({ a: { b: d => [, , { d }] }, arg: 1, c: 2 }), 1)
 })
 
+test('justin: parse.space override reaches feature handlers', () => {
+  const prevSpace = parse.space
+
+  parse.space = () => {
+    for (let cc; (cc = prevSpace()); ) {
+      if (cc !== 35) return cc
+      let i = idx + 1
+      while (cur[i] && cur.charCodeAt(i) !== 10) i++
+      seek(i)
+    }
+    return 0
+  }
+
+  try {
+    is(parse('a?.# custom\n[1]'), ['?.[]', 'a', [, 1]])
+    is(justin('a?.# custom\n[1]')({ a: [, 2] }), 2)
+  } finally {
+    parse.space = prevSpace
+  }
+})
+
 test('justin: nullish coalescing', () => {
   is(parse('a ?? b'), ['??', 'a', 'b'])
   is(justin('a ?? b')({ a: null, b: 'default' }), 'default')