Improve inference for paths leading to similar (#37163)

* Infer better eachindex broadcasting

* Fix a misuse of show_datatype

* Improve inference in vcat(A::BitMatrix...)

Because the tuple-length is unknown and because inference gives up
easily in the face of missing type parameters, the generator expressions
in the previous implementation were poorly inferred.

* Use Vector{String}  in Cmd field type

* Introduce ntupleany and use mapany in more places

This also makes mapany safe for iterators without `length`

* Add types to some comprehensions and lists

* Add some type-asserts and argtypes

* AbstractString->String in Distributed.ProcessGroup

* Update base/Enums.jl

* Update base/abstractarray.jl

Co-authored-by: Pablo Zubieta <8410335+pabloferz@users.noreply.github.com>

src/Distributed.jl

@@ -13,7 +13,8 @@ import Base: getindex, wait, put!, take!, fetch, isready, push!, length,
 using Base: Process, Semaphore, JLOptions, buffer_writes, @sync_add,
             VERSION_STRING, binding_module, atexit, julia_exename,
             julia_cmd, AsyncGenerator, acquire, release, invokelatest,
-            shell_escape_posixly, uv_error, something, notnothing, isbuffered
+            shell_escape_posixly, uv_error, something, notnothing, isbuffered,
+            mapany
 using Base.Threads: Event
 
 using Serialization, Sockets

src/cluster.jl

@@ -654,10 +654,10 @@ function create_worker(manager, wconfig)
         end
     end
 
-    all_locs = map(x -> isa(x, Worker) ?
-                   (something(x.config.connect_at, ()), x.id) :
-                   ((), x.id, true),
-                   join_list)
+    all_locs = mapany(x -> isa(x, Worker) ?
+                      (something(x.config.connect_at, ()), x.id) :
+                      ((), x.id, true),
+                      join_list)
     send_connection_hdr(w, true)
     enable_threaded_blas = something(wconfig.enable_threaded_blas, false)
     join_message = JoinPGRPMsg(w.id, all_locs, PGRP.topology, enable_threaded_blas, isclusterlazy())
@@ -765,7 +765,7 @@ let next_pid = 2    # 1 is reserved for the client (always)
 end
 
 mutable struct ProcessGroup
-    name::AbstractString
+    name::String
     workers::Array{Any,1}
     refs::Dict{RRID,Any}                  # global references
     topology::Symbol
@@ -1024,8 +1024,8 @@ end
 function _rmprocs(pids, waitfor)
     lock(worker_lock)
     try
-        rmprocset = []
-        for p in vcat(pids...)
+        rmprocset = Union{LocalProcess, Worker}[]
+        for p in pids
             if p == 1
                 @warn "rmprocs: process 1 not removed"
             else

src/macros.jl

@@ -275,7 +275,7 @@ function preduce(reducer, f, R)
         schedule(t)
         push!(w_exec, t)
     end
-    reduce(reducer, [fetch(t) for t in w_exec])
+    reduce(reducer, Any[fetch(t) for t in w_exec])
 end
 
 function pfor(f, R)

src/managers.jl

@@ -504,7 +504,7 @@ function connect(manager::ClusterManager, pid::Int, config::WorkerConfig)
 end
 
 function connect_w2w(pid::Int, config::WorkerConfig)
-    (rhost, rport) = notnothing(config.connect_at)::Tuple{AbstractString, Int}
+    (rhost, rport) = notnothing(config.connect_at)::Tuple{String, Int}
     config.host = rhost
     config.port = rport
     (s, bind_addr) = connect_to_worker(rhost, rport)

src/pmap.jl

@@ -201,7 +201,7 @@ extract_exception(e) = isa(e, RemoteException) ? e.captured.ex : e
 
 function process_batch_errors!(p, f, results, on_error, retry_delays, retry_check)
     # Handle all the ones in error in another pmap, with batch size set to 1
-    reprocess = []
+    reprocess = Tuple{Int,BatchProcessingError}[]
     for (idx, v) in enumerate(results)
         if isa(v, BatchProcessingError)
             push!(reprocess, (idx,v))
@@ -210,14 +210,14 @@ function process_batch_errors!(p, f, results, on_error, retry_delays, retry_chec
 
     if length(reprocess) > 0
         errors = [x[2] for x in reprocess]
-        exceptions = [x.ex for x in errors]
+        exceptions = Any[x.ex for x in errors]
         state = iterate(retry_delays)
         state !== nothing && (state = state[2])
         error_processed = let state=state
             if (length(retry_delays)::Int > 0) &&
                     (retry_check === nothing || all([retry_check(state,ex)[2] for ex in exceptions]))
                 # BatchProcessingError.data is a tuple of original args
-                pmap(x->f(x...), p, [x.data for x in errors];
+                pmap(x->f(x...), p, Any[x.data for x in errors];
                         on_error = on_error, retry_delays = collect(retry_delays)[2:end::Int], retry_check = retry_check)
             elseif on_error !== nothing
                 map(on_error, exceptions)