From 3349e87ef7b1ac381b7d9d16cee95a01bbae5428 Mon Sep 17 00:00:00 2001
From: Lionel Zoubritzky <lionel.zoubritzky@gmail.com>
Date: Wed, 2 Mar 2022 00:11:42 +0100
Subject: [PATCH] Factored representation for REPLCompletion

---
 stdlib/REPL/src/REPLCompletions.jl | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/stdlib/REPL/src/REPLCompletions.jl b/stdlib/REPL/src/REPLCompletions.jl
index 162d1184d18c39..190af01334b29b 100644
--- a/stdlib/REPL/src/REPLCompletions.jl
+++ b/stdlib/REPL/src/REPLCompletions.jl
@@ -42,8 +42,8 @@ end
 
 struct MethodCompletion <: Completion
     tt # may be used by an external consumer to infer return type, etc.
-    method::Method
-    MethodCompletion(@nospecialize(tt), method::Method) = new(tt, method)
+    method::Base.FactoredMethod
+    MethodCompletion(@nospecialize(tt), method::Base.FactoredMethod) = new(tt, method)
 end
 
 struct BslashCompletion <: Completion
@@ -78,7 +78,7 @@ function Base.getproperty(c::Completion, name::Symbol)
     elseif name === :field
         return getfield(c, :field)::Symbol
     elseif name === :method
-        return getfield(c, :method)::Method
+        return getfield(c, :method)::Base.FactoredMethod
     elseif name === :bslash
         return getfield(c, :bslash)::String
     elseif name === :text
@@ -575,7 +575,7 @@ function complete_any_methods(ex_org::Expr, callee_module::Module, context_modul
         filter!(out) do c
             isa(c, TextCompletion) && return false
             isa(c, MethodCompletion) || return true
-            sig = Base.unwrap_unionall(c.method.sig)::DataType
+            sig = Base.unwrap_unionall(c.method.m.sig)::DataType
             return !all(T -> T === Any || T === Vararg{Any}, sig.parameters[2:end])
         end
     end
@@ -611,15 +611,24 @@ end
 function complete_methods!(out::Vector{Completion}, @nospecialize(funct), args_ex::Vector{Any}, kwargs_ex::Bool, max_method_completions::Int)
     # Input types and number of arguments
     t_in = Tuple{funct, args_ex...}
-    m = Base._methods_by_ftype(t_in, nothing, max_method_completions, Base.get_world_counter(),
+    ml = Base._methods_by_ftype(t_in, nothing, max_method_completions, Base.get_world_counter(),
         #=ambig=# true, Ref(typemin(UInt)), Ref(typemax(UInt)), Ptr{Int32}(C_NULL))
-    if m === false
+    if ml === false
         push!(out, TextCompletion(sprint(Base.show_signature_function, funct) * "( too many methods to show )"))
     end
-    m isa Vector || return
-    for match in m
+    ml isa Vector || return
+    isempty(ml) && return
+    mm = [m::Core.MethodMatch for m in ml]
+    first_m = mm[1].method
+    if first_m.sig === Tuple # Builtin
+        push!(out, MethodCompletion(t_in, Base.FactoredMethod(first_m)))
+        return
+    end
+    mt = Base.get_methodtable(first_m)
+    fml = Base.FactoredMethodList(Base.MethodList([m.method for m in mm], mt))
+    for (fm, pos) in zip(fml.list, fml.positions)
         # TODO: if kwargs_ex, filter out methods without kwargs?
-        push!(out, MethodCompletion(match.spec_types, match.method))
+        push!(out, MethodCompletion(mm[last(pos)].spec_types, fm))
     end
 end