repr: allow context pairs when calling show

use this instead of the special-case `Base.reprfull` in loading

Author: StefanKarpinski

base/loading.jl

@@ -1047,12 +1047,6 @@ function evalfile(path::AbstractString, args::Vector{String}=String[])
 end
 evalfile(path::AbstractString, args::Vector) = evalfile(path, String[args...])
 
-function reprfull(x)
-    s = IOBuffer()
-    show(IOContext(s, :module => nothing), x)
-    String(take!(s))
-end
-
 function create_expr_cache(input::String, output::String, concrete_deps::typeof(_concrete_dependencies), uuid::Union{Nothing,UUID})
     rm(output, force=true)   # Remove file if it exists
     code_object = """
@@ -1072,7 +1066,7 @@ function create_expr_cache(input::String, output::String, concrete_deps::typeof(
         write(in, """
         begin
         empty!(Base.LOAD_PATH)
-        append!(Base.LOAD_PATH, $(reprfull(LOAD_PATH)))
+        append!(Base.LOAD_PATH, $(repr(LOAD_PATH, :module => nothing)))
         empty!(Base.DEPOT_PATH)
         append!(Base.DEPOT_PATH, $(repr(DEPOT_PATH)))
         empty!(Base.LOAD_CACHE_PATH)

base/strings/io.jl

@@ -151,8 +151,11 @@ end
 
 """
     repr(x)
+    repr(x, context::Pair{Symbol,<:Any}...)
 
 Create a string from any value using the [`show`](@ref) function.
+If context pairs are given, the IO buffer used to capture `show` output
+is wrapped in an `IOContext` object with those context pairs.
 
 # Examples
 ```jldoctest
@@ -170,6 +173,12 @@ function repr(x)
     String(take!(s))
 end
 
+function repr(x, context::Pair{Symbol}...)
+    s = IOBuffer()
+    show(IOContext(s, context...), x)
+    String(take!(s))
+end
+
 # IOBuffer views of a (byte)string:
 
 """