Working fix, sans JuliaSyntax

Author: mlechu

base/views.jl

@@ -18,16 +18,14 @@ replace_ref_begin_end!(ex) = replace_ref_begin_end_!(ex, nothing)[1]
 # replace_ref_begin_end_!(ex,withex) returns (new ex, whether withex was used)
 function replace_ref_begin_end_!(ex, withex)
     used_withex = false
-    if isa(ex,Symbol)
-        if ex === :begin
+    if isa(ex,Expr)
+        if ex.head === :begin
             withex === nothing && error("Invalid use of begin")
             return withex[1], true
-        elseif ex === :end
+        elseif ex.head === :end
             withex === nothing && error("Invalid use of end")
             return withex[2], true
-        end
-    elseif isa(ex,Expr)
-        if ex.head === :ref
+        elseif ex.head === :ref
             ex.args[1], used_withex = replace_ref_begin_end_!(ex.args[1], withex)
             S = isa(ex.args[1],Symbol) ? ex.args[1]::Symbol : gensym(:S) # temp var to cache ex.args[1] if needed
             used_S = false # whether we actually need S

src/julia-parser.scm

@@ -182,7 +182,7 @@
 (define space-sensitive #f)
 ; seeing `for` stops parsing macro arguments and makes a generator
 (define for-generator #f)
-; treat 'end' like a normal symbol instead of a reserved word
+; treat begin/end like special symbols instead of reserved words
 (define end-symbol #f)
 ; treat newline like ordinary whitespace instead of as a potential separator
 (define whitespace-newline #f)
@@ -1624,7 +1624,7 @@
         (parse-imports s word))
        ((do)
         (error "invalid \"do\" syntax"))
-       (else (error "unhandled reserved word")))))))
+       (else (error (string "unhandled reserved word " word))))))))
 
 (define (parse-do s)
   (with-bindings
@@ -2545,6 +2545,10 @@
                     (symbol str)))
                  ((eq? t 'true)  '(true))
                  ((eq? t 'false) '(false))
+                 ;; issue #57269: a[var"begin"] -> 'begin
+                 ;;               a[begin]      -> '(begin)
+                 ((and end-symbol (eq? t 'begin)) '(begin))
+                 ((and end-symbol (eq? t 'end)) '(end))
                  (else t)))
 
           ;; parens or tuple

src/julia-syntax.scm

@@ -113,8 +113,8 @@
 
 ;; replace `begin` and `end` for the closest ref expression, so doesn't go inside nested refs
 (define (replace-beginend ex a n tuples last)
-  (cond ((eq? ex 'end)                (end-val a n tuples last))
-        ((eq? ex 'begin)              (begin-val a n tuples last))
+  (cond ((equal? ex '(begin))         (begin-val a n tuples last))
+        ((equal? ex '(end))           (end-val a n tuples last))
         ((or (atom? ex) (quoted? ex)) ex)
         ((eq? (car ex) 'ref)
          ;; inside ref only replace within the first argument
@@ -1736,7 +1736,9 @@
   (let ((a    (cadr e))
         (idxs (cddr e)))
     (let* ((reuse (and (pair? a)
-                       (contains (lambda (x) (or (eq? x 'begin) (eq? x 'end)))
+                       (contains (lambda (x)
+                                   (or (equal? x '(begin))
+                                       (equal? x '(end))))
                                  idxs)))
            (arr   (if reuse (make-ssavalue) a))
            (stmts (if reuse `((= ,arr ,a)) '())))
@@ -2573,8 +2575,9 @@
                 (idxs (cddr lhs))
                 (rhs  (caddr e)))
             (let* ((reuse (and (pair? a)
-                               (contains (lambda (x) (eq? x 'end))
-                                         idxs)))
+                               (contains
+                                (lambda (x) (equal? x '(end)))
+                                idxs)))
                    (arr   (if reuse (make-ssavalue) a))
                    (stmts (if reuse `((= ,arr ,(expand-forms a))) '()))
                    (rrhs (and (pair? rhs) (not (ssavalue? rhs)) (not (quoted? rhs))))