Rename unshift!/shift! to pushfirst!/popfirst!

NEWS.md

@@ -861,6 +861,13 @@ Deprecated or removed
     `unsafe_get`/`get` can be dropped or replaced with `coalesce`.
     `NullException` has been removed.
 
+  * `unshift!` and `shift!` have been renamed to `pushfirst!` and `popfirst!` ([#23902])
+
+  * `Nullable{T}` has been deprecated and moved to the Nullables package ([#23642]).
+    Use `Union{T, Void}` instead, or `Union{Some{T}, Void}` if `nothing` is a possible value
+    (i.e. `Void <: T`). `isnull(x)` can be replaced with `x === nothing`
+    and `unsafe_get`/`get` can be dropped or replaced with `coalesce`.
+
   * `CartesianRange` has been renamed `CartesianIndices` ([#24715]).
 
   * `sub2ind` and `ind2sub` are deprecated in favor of using `CartesianIndices` and `LinearIndices` ([#24715]).

base/abstractarray.jl

@@ -1933,12 +1933,12 @@ map!(f::F, dest::AbstractArray, As::AbstractArray...) where {F} = map_n!(f, dest
 map(f) = f()
 map(f, iters...) = collect(Generator(f, iters...))
 
-# multi-item push!, unshift! (built on top of type-specific 1-item version)
+# multi-item push!, pushfirst! (built on top of type-specific 1-item version)
 # (note: must not cause a dispatch loop when 1-item case is not defined)
 push!(A, a, b) = push!(push!(A, a), b)
 push!(A, a, b, c...) = push!(push!(A, a, b), c...)
-unshift!(A, a, b) = unshift!(unshift!(A, b), a)
-unshift!(A, a, b, c...) = unshift!(unshift!(A, c...), a, b)
+pushfirst!(A, a, b) = pushfirst!(pushfirst!(A, b), a)
+pushfirst!(A, a, b, c...) = pushfirst!(pushfirst!(A, c...), a, b)
 
 ## hashing collections ##
 

base/array.jl

@@ -869,7 +869,7 @@ function prepend!(a::Array{<:Any,1}, items::AbstractVector)
 end
 
 prepend!(a::Vector, iter) = _prepend!(a, iteratorsize(iter), iter)
-unshift!(a::Vector, iter...) = prepend!(a, iter)
+pushfirst!(a::Vector, iter...) = prepend!(a, iter)
 
 function _prepend!(a, ::Union{HasLength,HasShape}, iter)
     n = length(iter)
@@ -884,7 +884,7 @@ function _prepend!(a, ::IteratorSize, iter)
     n = 0
     for item in iter
         n += 1
-        unshift!(a, item)
+        pushfirst!(a, item)
     end
     reverse!(a, 1, n)
     a
@@ -990,13 +990,13 @@ function pop!(a::Vector)
 end
 
 """
-    unshift!(collection, items...) -> collection
+    pushfirst!(collection, items...) -> collection
 
 Insert one or more `items` at the beginning of `collection`.
 
 # Examples
 ```jldoctest
-julia> unshift!([1, 2, 3, 4], 5, 6)
+julia> pushfirst!([1, 2, 3, 4], 5, 6)
 6-element Array{Int64,1}:
  5
  6
@@ -1006,15 +1006,15 @@ julia> unshift!([1, 2, 3, 4], 5, 6)
  4
 ```
 """
-function unshift!(a::Array{T,1}, item) where T
+function pushfirst!(a::Array{T,1}, item) where T
     item = convert(T, item)
     _growbeg!(a, 1)
     a[1] = item
     return a
 end
 
 """
-    shift!(collection) -> item
+    popfirst!(collection) -> item
 
 Remove the first `item` from `collection`.
 
@@ -1029,7 +1029,7 @@ julia> A = [1, 2, 3, 4, 5, 6]
  5
  6
 
-julia> shift!(A)
+julia> popfirst!(A)
 1
 
 julia> A
@@ -1041,7 +1041,7 @@ julia> A
  6
 ```
 """
-function shift!(a::Vector)
+function popfirst!(a::Vector)
     if isempty(a)
         throw(ArgumentError("array must be non-empty"))
     end

base/bitarray.jl

@@ -813,7 +813,7 @@ function pop!(B::BitVector)
     return item
 end
 
-function unshift!(B::BitVector, item)
+function pushfirst!(B::BitVector, item)
     item = convert(Bool, item)
 
     Bc = B.chunks
@@ -835,7 +835,7 @@ function unshift!(B::BitVector, item)
     return B
 end
 
-function shift!(B::BitVector)
+function popfirst!(B::BitVector)
     isempty(B) && throw(ArgumentError("argument must not be empty"))
     @inbounds begin
         item = B[1]

base/bitset.jl

@@ -246,7 +246,7 @@ end
 @inline delete!(s::BitSet, n::Int) = _setint!(s, n, false)
 @inline delete!(s::BitSet, n::Integer) = _is_convertible_Int(n) ? delete!(s, Int(n)) : s
 
-shift!(s::BitSet) = pop!(s, first(s))
+popfirst!(s::BitSet) = pop!(s, first(s))
 
 function empty!(s::BitSet)
     empty!(s.bits)

base/channels.jl

@@ -286,7 +286,7 @@ function put_unbuffered(c::Channel, v)
             rethrow(ex)
         end
     end
-    taker = shift!(c.takers)
+    taker = popfirst!(c.takers)
     yield(taker, v) # immediately give taker a chance to run, but don't block the current task
     return v
 end
@@ -318,23 +318,23 @@ task.
 take!(c::Channel) = isbuffered(c) ? take_buffered(c) : take_unbuffered(c)
 function take_buffered(c::Channel)
     wait(c)
-    v = shift!(c.data)
+    v = popfirst!(c.data)
     notify(c.cond_put, nothing, false, false) # notify only one, since only one slot has become available for a put!.
     v
 end
 
-shift!(c::Channel) = take!(c)
+popfirst!(c::Channel) = take!(c)
 
 # 0-size channel
 function take_unbuffered(c::Channel{T}) where T
     check_channel_state(c)
     push!(c.takers, current_task())
     try
         if length(c.putters) > 0
-            let refputter = Ref(shift!(c.putters))
+            let refputter = Ref(popfirst!(c.putters))
                 return Base.try_yieldto(refputter) do putter
                     # if we fail to start putter, put it back in the queue
-                    putter === current_task || unshift!(c.putters, putter)
+                    putter === current_task || pushfirst!(c.putters, putter)
                 end::T
             end
         else

base/client.jl

@@ -283,7 +283,7 @@ function process_options(opts::JLOptions)
     end
 
     # remove filename from ARGS
-    global PROGRAM_FILE = arg_is_program ? shift!(ARGS) : ""
+    global PROGRAM_FILE = arg_is_program ? popfirst!(ARGS) : ""
 
     # Load Distributed module only if any of the Distributed options have been specified.
     if (opts.worker == 1) || (opts.nprocs > 0) || (opts.machinefile != C_NULL)
@@ -350,7 +350,7 @@ interactive sessions; this is useful to customize the interface. The argument of
 REPL object. This function should be called from within the `.juliarc.jl` initialization
 file.
 """
-atreplinit(f::Function) = (unshift!(repl_hooks, f); nothing)
+atreplinit(f::Function) = (pushfirst!(repl_hooks, f); nothing)
 
 function __atreplinit(repl)
     for f in repl_hooks

base/deprecated.jl

@@ -859,7 +859,7 @@ function produce(v)
             empty = true
             break
         elseif isa(q,Condition) && !isempty(q.waitq)
-            t = shift!(q.waitq)
+            t = popfirst!(q.waitq)
             empty = isempty(q.waitq)
             break
         end
@@ -3427,6 +3427,11 @@ workspace() = error("workspace() is discontinued, check out Revise.jl for an alt
 # Issue #12902
 @deprecate parentindexes parentindices
 
+# Issue #23902
+@deprecate unshift! pushfirst!
+@deprecate shift! popfirst!
+
+# Issue #23642
 @deprecate_moved Nullable "Nullables"
 @deprecate_moved NullException "Nullables"
 @deprecate_moved isnull "Nullables"

base/docs/utils.jl

@@ -231,11 +231,11 @@ function matchinds(needle, haystack; acronym = false)
     lastc = '\0'
     for (i, char) in enumerate(haystack)
         isempty(chars) && break
-        while chars[1] == ' ' shift!(chars) end # skip spaces
+        while chars[1] == ' ' popfirst!(chars) end # skip spaces
         if Unicode.lowercase(char) == Unicode.lowercase(chars[1]) &&
            (!acronym || !Unicode.isalpha(lastc))
             push!(is, i)
-            shift!(chars)
+            popfirst!(chars)
         end
         lastc = char
     end

base/event.jl

@@ -70,7 +70,7 @@ function notify(c::Condition, arg, all, error)
         empty!(c.waitq)
     elseif !isempty(c.waitq)
         cnt = 1
-        t = shift!(c.waitq)
+        t = popfirst!(c.waitq)
         error ? schedule(t, arg, error=error) : schedule(t, arg)
     end
     cnt
@@ -223,7 +223,7 @@ function ensure_rescheduled(othertask::Task)
     if ct !== othertask && othertask.state == :runnable
         # we failed to yield to othertask
         # return it to the head of the queue to be scheduled later
-        unshift!(Workqueue, othertask)
+        pushfirst!(Workqueue, othertask)
         othertask.state = :queued
     end
     if ct.state == :queued
@@ -238,14 +238,14 @@ function ensure_rescheduled(othertask::Task)
 end
 
 @noinline function poptask()
-    t = shift!(Workqueue)
+    t = popfirst!(Workqueue)
     if t.state != :queued
         # assume this somehow got queued twice,
         # probably broken now, but try discarding this switch and keep going
         # can't throw here, because it's probably not the fault of the caller to wait
         # and don't want to use print() here, because that may try to incur a task switch
         ccall(:jl_safe_printf, Cvoid, (Ptr{UInt8}, Int32...),
-            "\nWARNING: Workqueue inconsistency detected: shift!(Workqueue).state != :queued\n")
+            "\nWARNING: Workqueue inconsistency detected: popfirst!(Workqueue).state != :queued\n")
         return
     end
     t.state = :runnable

base/exports.jl

@@ -631,8 +631,8 @@ export
     prepend!,
     push!,
     resize!,
-    shift!,
-    unshift!,
+    popfirst!,
+    pushfirst!,
 
 # collections
     all!,

base/expr.jl

@@ -231,7 +231,7 @@ function pushmeta!(ex::Expr, sym::Symbol, args::Any...)
         push!(exargs[idx].args, tag)
     else
         body::Expr = inner.args[2]
-        unshift!(body.args, Expr(:meta, tag))
+        pushfirst!(body.args, Expr(:meta, tag))
     end
     ex
 end

base/inference.jl

@@ -4494,14 +4494,14 @@ function invoke_NF(argexprs, @nospecialize(etype), atypes::Vector{Any}, sv::Opti
         ex.typ = etype
         ex.args = copy(argexprs)
         invoke_texpr === nothing || insert!(stmts, 2, invoke_texpr)
-        invoke_fexpr === nothing || unshift!(stmts, invoke_fexpr)
+        invoke_fexpr === nothing || pushfirst!(stmts, invoke_fexpr)
 
         local ret_var, merge, invoke_ex, spec_hit
         ret_var = add_slot!(sv.src, widenconst(etype), false)
         merge = genlabel(sv)
         invoke_ex = copy(ex)
         invoke_ex.head = :invoke
-        unshift!(invoke_ex.args, nothing)
+        pushfirst!(invoke_ex.args, nothing)
         spec_hit = false
 
         function splitunion(atypes::Vector{Any}, i::Int)
@@ -4532,8 +4532,8 @@ function invoke_NF(argexprs, @nospecialize(etype), atypes::Vector{Any}, sv::Opti
                             isa_var = newvar!(sv, Bool)
                             isa_ty = Expr(:call, GlobalRef(Core, :isa), aei, ty)
                             isa_ty.typ = Bool
-                            unshift!(match, Expr(:gotoifnot, isa_var, after.label))
-                            unshift!(match, Expr(:(=), isa_var, isa_ty))
+                            pushfirst!(match, Expr(:gotoifnot, isa_var, after.label))
+                            pushfirst!(match, Expr(:(=), isa_var, isa_ty))
                             append!(stmts, match)
                             push!(stmts, after)
                         else
@@ -4574,7 +4574,7 @@ function invoke_NF(argexprs, @nospecialize(etype), atypes::Vector{Any}, sv::Opti
         cache_linfo === nothing && return NF
         add_backedge!(cache_linfo, sv)
         argexprs = copy(argexprs)
-        unshift!(argexprs, cache_linfo)
+        pushfirst!(argexprs, cache_linfo)
         ex = Expr(:invoke)
         ex.args = argexprs
         ex.typ = etype
@@ -4666,8 +4666,8 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
         argexpr0 = argexprs[2]
         atypes = atypes[4:end]
         argexprs = argexprs[4:end]
-        unshift!(atypes, atype0)
-        unshift!(argexprs, argexpr0)
+        pushfirst!(atypes, atype0)
+        pushfirst!(argexprs, argexpr0)
         f = isdefined(ft, :instance) ? ft.instance : nothing
     elseif isa(f, IntrinsicFunction) || ft ⊑ IntrinsicFunction ||
             isa(f, Builtin) || ft ⊑ Builtin
@@ -4885,7 +4885,7 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
         aei = argexprs[i]
         aeitype = argtype = widenconst(exprtype(aei, sv.src, sv.mod))
         if i == 1 && !(invoke_texpr === nothing)
-            unshift!(prelude_stmts, invoke_texpr)
+            pushfirst!(prelude_stmts, invoke_texpr)
         end
 
         # ok for argument to occur more than once if the actual argument
@@ -4912,15 +4912,15 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
             if occ != 0
                 vnew = newvar!(sv, aeitype)
                 argexprs[i] = vnew
-                unshift!(prelude_stmts, Expr(:(=), vnew, aei))
+                pushfirst!(prelude_stmts, Expr(:(=), vnew, aei))
                 stmts_free &= free
             elseif !free && !isType(aeitype)
-                unshift!(prelude_stmts, aei)
+                pushfirst!(prelude_stmts, aei)
                 stmts_free = false
             end
         end
     end
-    invoke_fexpr === nothing || unshift!(prelude_stmts, invoke_fexpr)
+    invoke_fexpr === nothing || pushfirst!(prelude_stmts, invoke_fexpr)
 
     # re-number the SSAValues and copy their type-info to the new ast
     ssavalue_types = src.ssavaluetypes
@@ -4985,7 +4985,7 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
                     retval = add_slot!(sv.src, rettype, false)
                 end
                 multiret = true
-                unshift!(a.args, retval)
+                pushfirst!(a.args, retval)
                 a.head = :(=)
                 push!(stmts, GotoNode(retstmt.label))
             end
@@ -4994,7 +4994,7 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
 
     if multiret
         if lastexpr !== nothing
-            unshift!(lastexpr.args, retval)
+            pushfirst!(lastexpr.args, retval)
             lastexpr.head = :(=)
             push!(stmts, lastexpr)
         end
@@ -5023,7 +5023,7 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
         if !do_coverage && all(inlining_ignore, stmts)
             empty!(stmts)
         elseif isa(stmts[1], LineNumberNode)
-            linenode = shift!(stmts)::LineNumberNode
+            linenode = popfirst!(stmts)::LineNumberNode
             line = linenode.line
             isa(linenode.file, Symbol) && (file = linenode.file)
         end
@@ -5035,15 +5035,15 @@ function inlineable(@nospecialize(f), @nospecialize(ft), e::Expr, atypes::Vector
         # function inlined in it
         mod = method.module
         if mod === sv.mod
-            unshift!(stmts, Expr(:meta, :push_loc, file,
+            pushfirst!(stmts, Expr(:meta, :push_loc, file,
                                  method.name, line))
         else
-            unshift!(stmts, Expr(:meta, :push_loc, file,
+            pushfirst!(stmts, Expr(:meta, :push_loc, file,
                                  method.name, line, mod))
         end
         push!(stmts, Expr(:meta, :pop_loc))
     elseif !isempty(stmts)
-        unshift!(stmts, Expr(:meta, :push_loc, file,
+        pushfirst!(stmts, Expr(:meta, :push_loc, file,
                              method.name, line))
         if isa(stmts[end], LineNumberNode)
             stmts[end] = Expr(:meta, :pop_loc)