consistent quoting of import Base.:operator and warnings thereof

NEWS.md

@@ -6,6 +6,8 @@ New language features
 
 * Structs with all isbits and isbitsunion fields are now stored inline in arrays ([#32448]).
 
+* `import` now allows quoted symbols, e.g. `import Base.:+` ([#33158]).
+
 Language changes
 ----------------
 

base/errorshow.jl

@@ -235,15 +235,14 @@ function showerror(io::IO, ex::MethodError)
     if f_is_function && isdefined(Base, name)
         basef = getfield(Base, name)
         if basef !== ex.f && hasmethod(basef, arg_types)
-            println(io)
-            print(io, "You may have intended to import Base.", name)
+            print(io, "\nYou may have intended to import ")
+            show_unquoted(io, Expr(:., :Base, QuoteNode(name)))
         end
     end
     if (ex.world != typemax(UInt) && hasmethod(ex.f, arg_types) &&
         !hasmethod(ex.f, arg_types, world = ex.world))
         curworld = get_world_counter()
-        println(io)
-        print(io, "The applicable method may be too new: running in world age $(ex.world), while current world is $(curworld).")
+        print(io, "\nThe applicable method may be too new: running in world age $(ex.world), while current world is $(curworld).")
     end
     if !is_arg_types
         # Check for row vectors used where a column vector is intended.
@@ -455,8 +454,7 @@ function show_method_candidates(io::IO, ex::MethodError, @nospecialize kwargs=()
 
     if !isempty(lines) # Display up to three closest candidates
         Base.with_output_color(:normal, io) do io
-            println(io)
-            print(io, "Closest candidates are:")
+            print(io, "\nClosest candidates are:")
             sort!(lines, by = x -> -x[2])
             i = 0
             for line in lines

src/ast.scm

@@ -274,6 +274,10 @@
 
 (define (quoted? e) (memq (car e) '(quote top core globalref outerref line break inert meta)))
 (define (quotify e) `',e)
+(define (unquote e)
+  (if (and (pair? e) (memq (car e) '(quote inert)))
+      (cadr e)
+      e))
 
 (define (lam:args x) (cadr x))
 (define (lam:vars x) (llist-vars (lam:args x)))

src/julia-parser.scm

@@ -1602,7 +1602,7 @@
        ((eq? nxt '|.|)
         (if (ts:space? s) (disallowed-space word nxt))
         (take-token s)
-        (loop (cons (macrocall-to-atsym (parse-unary-prefix s)) path)))
+        (loop (cons (unquote (macrocall-to-atsym (parse-unary-prefix s))) path)))
        ((or (memv nxt '(#\newline #\; #\, :))
             (eof-object? nxt))
         (cons '|.| (reverse path)))

test/errorshow.jl

@@ -206,7 +206,7 @@ import ..@except_str
 global +
 +() = nothing
 err_str = @except_str 1 + 2 MethodError
-@test occursin("import Base.+", err_str)
+@test occursin("import Base.:+", err_str)
 
 err_str = @except_str Float64[](1) MethodError
 @test !occursin("import Base.Array", err_str)
@@ -578,3 +578,19 @@ let t1 = @async(error(1)),
     @test length(findall("Stacktrace:", s)) == 2
     @test occursin("[1] error(::Int", s)
 end
+
+module TestMethodShadow
+    struct Foo; x; end
+    +(a::Foo, b::Foo) = Foo(a.x + b.x)
+    ==(a::Foo, b::Foo) = Foo(a.x == b.x)
+    div(a::Foo, b::Foo) = Foo(div(a.x, b.x))
+end
+for (func,str) in ((TestMethodShadow.:+,":+"), (TestMethodShadow.:(==),":(==)"), (TestMethodShadow.:div,"div"))
+    ex = try
+        foo = TestMethodShadow.Foo(3)
+        func(foo,foo)
+    catch e
+       e
+    end::MethodError
+    @test occursin("You may have intended to import Base.$str", sprint(Base.showerror, ex))
+end

test/syntax.jl

@@ -1928,10 +1928,15 @@ end
 # Stream positioning after parsing var
 @test Meta.parse("var'", 1, greedy=false) == (:var, 4)
 
+# quoted names in import (#33158)
+@test Meta.parse("import Base.:+") == :(import Base.+)
+@test Meta.parse("import Base.Foo.:(==).bar") == :(import Base.Foo.==.bar)
+
 # issue #33135
 function f33135(x::T) where {C1, T}
     let C1 = 1, C2 = 2
         C1
     end
 end
 @test f33135(0) == 1
+