[julia] Make REPL AST transform more robust.

.julia/config/startup.jl

@@ -1,17 +1,15 @@
 if Base.isinteractive() &&
    (local REPL = get(Base.loaded_modules, Base.PkgId(Base.UUID("3fa0cd96-eef1-5676-8a61-b3b8758bbffb"), "REPL"), nothing); REPL !== nothing)
 
-    # Exit Julia with :q
+    # Exit Julia with :q, restart with :r
     pushfirst!(REPL.repl_ast_transforms, function(ast::Union{Expr,Nothing})
-        if Meta.isexpr(ast, :toplevel, 2) && ast.args[2] === QuoteNode(:q)
-            exit()
+        function toplevel_quotenode(ast, s)
+            return (Meta.isexpr(ast, :toplevel, 2) && ast.args[2] === QuoteNode(s)) ||
+                   (Meta.isexpr(ast, :toplevel) && any(x -> toplevel_quotenode(x, s), ast.args))
         end
-        return ast
-    end)
-
-    # Restart Julia with :r
-    pushfirst!(REPL.repl_ast_transforms, function(ast::Union{Expr,Nothing})
-        if Meta.isexpr(ast, :toplevel, 2) && ast.args[2] === QuoteNode(:r)
+        if toplevel_quotenode(ast, :q)
+            exit()
+        elseif toplevel_quotenode(ast, :r)
             argv = Base.julia_cmd().exec
             opts = Base.JLOptions()
             if opts.project != C_NULL
@@ -25,25 +23,27 @@ if Base.isinteractive() &&
         return ast
     end)
 
-    # Automatically load Debugger.jl when encountering @enter or @run and BenchmarkTools.jl
-    # when encountering @btime or @benchmark.
+    # Automatically load tooling on demand:
+    # - Debugger.jl when encountering @enter or @run
+    # - BenchmarkTools.jl when encountering @btime or @benchmark
     pushfirst!(REPL.repl_ast_transforms, function(ast::Union{Expr,Nothing})
-        contains_macro(_, _) = false
-        function contains_macro(x::Expr, s::Symbol)
-            (Meta.isexpr(x, :macrocall) && x.args[1] === s) ||
-            any(y -> contains_macro(y, s), x.args)
+        function contains_macro(ast, m)
+            return ast isa Expr && (
+                (Meta.isexpr(ast, :macrocall) && ast.args[1] === m) ||
+                any(x -> contains_macro(x, m), ast.args)
+            )
         end
-        if Meta.isexpr(ast, :toplevel, 2) &&
-           !isdefined(Main, :Debugger)    &&
-           (contains_macro(ast, Symbol("@enter")) || contains_macro(ast, Symbol("@run")))
+        if !isdefined(Main, :Debugger) && (
+            contains_macro(ast, Symbol("@enter")) || contains_macro(ast, Symbol("@run"))
+        )
             @info "Loading Debugger ..."
             try
                 Core.eval(Main, :(using Debugger))
             catch
             end
-        elseif Meta.isexpr(ast, :toplevel, 2) &&
-           !isdefined(Main, :BenchmarkTools)  &&
-           (contains_macro(ast, Symbol("@btime")) || contains_macro(ast, Symbol("@benchmark")))
+        elseif !isdefined(Main, :BenchmarkTools) && (
+            contains_macro(ast, Symbol("@btime")) || contains_macro(ast, Symbol("@benchmark"))
+        )
             @info "Loading BenchmarkTools ..."
             try
                 Core.eval(Main, :(using BenchmarkTools))
@@ -52,4 +52,5 @@ if Base.isinteractive() &&
         end
         return ast
     end)
+
 end