range: Remove one positional arg syntax

Author: mkitti

base/range.jl

@@ -50,7 +50,6 @@ end
     range(start, stop; length, step)
     range(start; length, stop, step)
     range(;start, length, stop, step)
-    range(stop)
 
 Construct a specialized array with evenly spaced elements and optimized storage (an [`AbstractRange`](@ref)) from the arguments.
 Mathematically a range is uniquely determined by any three of `start`, `step`, `stop` and `length`.
@@ -90,9 +89,6 @@ julia> range(stop=10, step=1, length=5)
 julia> range(start=1, step=1, stop=10)
 1:1:10
 
-julia> range(5)
-Base.OneTo(5)
-
 julia> range(; length = 10)
 Base.OneTo(10)
 
@@ -136,7 +132,7 @@ A `UnitRange` is not produced if `step` is provided even if specified as one.
 function range end
 
 range(start; stop=nothing, length::Union{Integer,Nothing}=nothing, step=nothing) =
-    _range_positional(start, step, stop, length)
+    _range(start, step, stop, length)
 
 function range(start, stop; length::Union{Integer,Nothing}=nothing, step=nothing)
     # For code clarity, the user must pass step or length
@@ -156,13 +152,6 @@ end
 range(;start=nothing, stop=nothing, length::Union{Integer, Nothing}=nothing, step=nothing) =
     _range(start, step, stop, length)
 
-range(stop::Integer) = range_stop(stop)
-
-_range_positional(stop::Any    , step::Nothing,      ::Nothing, len::Nothing) =
-    _range(nothing, nothing, stop, nothing) # One arg interpreted as `stop`, could be nothing
-_range_positional(start::Any    , step::Any    , stop::Any,     len::Any) =
-    _range(start, step, stop, len)
-
 _range(start::Nothing, step::Nothing, stop::Nothing, len::Nothing) = range_error(start, step, stop, len)
 _range(start::Nothing, step::Nothing, stop::Nothing, len::Any    ) = range_length(len)
 _range(start::Nothing, step::Nothing, stop::Any    , len::Nothing) = range_stop(stop)

test/ranges.jl

@@ -21,15 +21,14 @@
         r = 1:5
         o = Base.OneTo(5)
         let start=first(r), step=step(r), stop=last(r), length=length(r)
-        @test o === range(                     length)
         @test o === range(;              stop        )
         @test o === range(;                    length)
         @test r === range(; start,       stop        )
         @test r === range(;              stop, length)
         # the next three lines uses ==, because it changes the eltype
         @test r ==  range(; start,       stop, length)
         @test r ==  range(; start, step,       length)
-        @test r ==  range(Float64(stop))
+        @test r ==  range(; stop=Float64(stop))
         end
     end
 end
@@ -1458,6 +1457,7 @@ end
 
 @testset "Bad range calls" begin
     @test_throws ArgumentError range(nothing)
+    @test_throws ArgumentError range(5)
     @test_throws ArgumentError range(1, step=4)
     @test_throws ArgumentError range(; step=1, length=6)
     @test_throws ArgumentError range(; step=2, stop=7.5)