Consider newlines as spaces for space-sensitive parsing

src/julia-parser.scm

@@ -597,6 +597,9 @@
    (begin0 (ts:last-tok s)
            (ts:set-tok! s #f))))
 
+(define (space-before-next-token? s)
+  (or (skip-ws (ts:port s) #f) (eqv? #\newline (peek-char (ts:port s)))))
+
 ;; --- misc ---
 
 ; Log a syntax deprecation, attributing it to current-filename and the line
@@ -744,7 +747,7 @@
           (take-token s)
           (cond ((eq? t '~) ;; ~ is the only non-syntactic assignment-precedence operators
                  (if (and space-sensitive (ts:space? s)
-                          (not (eqv? (peek-char (ts:port s)) #\ )))
+                          (not (space-before-next-token? s)))
                      (begin (ts:put-back! s t (ts:space? s))
                             ex)
                      (list 'call t ex (parse-assignment s down))))
@@ -839,7 +842,7 @@
             ((and range-colon-enabled (eq? t ':))
              (take-token s)
              (if (and space-sensitive spc
-                      (or (peek-token s) #t) (not (ts:space? s)))
+                      (not (space-before-next-token? s)))
                  ;; "a :b" in space sensitive mode
                  (begin (ts:put-back! s ': spc)
                         ex)
@@ -873,7 +876,7 @@
           (let ((spc (ts:space? s)))
             (take-token s)
             (cond ((and space-sensitive spc (memq t unary-and-binary-ops)
-                        (not (eqv? (peek-char (ts:port s)) #\ )))
+                        (not (space-before-next-token? s)))
                    ;; here we have "x -y"
                    (ts:put-back! s t spc)
                    (reverse! chain))
@@ -890,7 +893,7 @@
           (let ((spc (ts:space? s)))
             (take-token s)
             (cond ((and space-sensitive spc (memq t unary-and-binary-ops)
-                        (not (eqv? (peek-char (ts:port s)) #\ )))
+                        (not (space-before-next-token? s)))
                    ;; here we have "x -y"
                    (ts:put-back! s t spc)
                    ex)

test/parse.jl

@@ -226,6 +226,32 @@ end
 # error throwing branch from #10560
 @test_throws ArgumentError Base.tryparse_internal(Bool, "foo", 1, 2, 10, true)
 
+# issue #16594
+@test Meta.parse("@x a + \nb") == Meta.parse("@x a +\nb")
+@test [1 +
+       1] == [2]
+@test [1 +1] == [1 1]
+
+# issue #16594, note for the macro tests, order is important
+# because the line number is included as part of the expression
+# (i.e. both macros must start on the same line)
+@test :(@test((1+1) == 2)) == :(@test 1 +
+                                      1 == 2)
+@test :(@x 1 +1 -1) == :(@x(1, +1, -1))
+@test :(@x 1 + 1 -1) == :(@x(1+1, -1))
+@test :(@x 1 + 1 - 1) == :(@x(1 + 1 - 1))
+@test :(@x(1 + 1 - 1)) == :(@x 1 +
+                               1 -
+                               1)
+@test :(@x(1 + 1 + 1)) == :(@x 1 +
+                               1 +
+                               1)
+@test :([x .+
+          y]) == :([x .+ y])
+
+# line break in : expression disallowed
+@test_throws Meta.ParseError Meta.parse("[1 :\n2] == [1:2]")
+
 @test tryparse(Float64, "1.23") === 1.23
 @test tryparse(Float32, "1.23") === 1.23f0
 @test tryparse(Float16, "1.23") === Float16(1.23)