Remove DirectIndexString from Base (#24262)

Author: bkamins

base/boot.jl

@@ -130,7 +130,7 @@ export
     Signed, Int, Int8, Int16, Int32, Int64, Int128,
     Unsigned, UInt, UInt8, UInt16, UInt32, UInt64, UInt128,
     # string types
-    Char, DirectIndexString, AbstractString, String, IO,
+    Char, AbstractString, String, IO,
     # errors
     ErrorException, BoundsError, DivideError, DomainError, Exception,
     InterruptException, InexactError, OutOfMemoryError, ReadOnlyMemoryError,
@@ -275,8 +275,6 @@ struct InitError <: WrappedException
     error
 end
 
-abstract type DirectIndexString <: AbstractString end
-
 String(s::String) = s  # no constructor yet
 
 # This should always be inlined

base/strings/basic.jl

@@ -4,7 +4,6 @@
 
 endof(s::AbstractString) = error("you must implement endof(", typeof(s), ")")
 next(s::AbstractString, i::Int) = error("you must implement next(", typeof(s), ",Int)")
-next(s::DirectIndexString, i::Int) = (s[i],i+1)
 next(s::AbstractString, i::Integer) = next(s,Int(i))
 
 string() = ""
@@ -70,8 +69,6 @@ julia> 'j' * "ulia"
 
 one(::Union{T,Type{T}}) where {T<:AbstractString} = convert(T, "")
 
-length(s::DirectIndexString) = endof(s)
-
 """
     length(s::AbstractString)
 
@@ -198,8 +195,6 @@ isless(a::Symbol, b::Symbol) = cmp(a,b) < 0
 
 ## Generic validation functions ##
 
-isvalid(s::DirectIndexString, i::Integer) = (start(s) <= i <= endof(s))
-
 """
     isvalid(str::AbstractString, i::Integer)
 
@@ -237,20 +232,6 @@ end
 
 ## Generic indexing functions ##
 
-prevind(s::DirectIndexString, i::Integer) = Int(i)-1
-nextind(s::DirectIndexString, i::Integer) = Int(i)+1
-
-function prevind(s::DirectIndexString, i::Integer, nchar::Integer)
-    nchar > 0 || throw(ArgumentError("nchar must be greater than 0"))
-    Int(i)-nchar
-end
-
-function nextind(s::DirectIndexString, i::Integer, nchar::Integer)
-    nchar > 0 || throw(ArgumentError("nchar must be greater than 0"))
-    Int(i)+nchar
-end
-
-
 """
     prevind(str::AbstractString, i::Integer, nchar::Integer=1)
 
@@ -371,9 +352,6 @@ checkbounds(s::AbstractString, r::AbstractRange{<:Integer}) = isempty(r) || (min
 checkbounds(s::AbstractString, I::AbstractArray{<:Real}) = all(i -> checkbounds(s, i), I)
 checkbounds(s::AbstractString, I::AbstractArray{<:Integer}) = all(i -> checkbounds(s, i), I)
 
-ind2chr(s::DirectIndexString, i::Integer) = begin checkbounds(s,i); i end
-chr2ind(s::DirectIndexString, i::Integer) = begin checkbounds(s,i); i end
-
 
 """
     ind2chr(s::AbstractString, i::Integer)

base/strings/types.jl

@@ -59,8 +59,6 @@ sizeof(s::SubString{String}) = s.endof == 0 ? 0 : nextind(s, s.endof) - 1
 # default implementation will work but it's slow
 # can this be delegated efficiently somehow?
 # that may require additional string interfaces
-length(s::SubString{<:DirectIndexString}) = endof(s)
-
 function length(s::SubString{String})
     return s.endof==0 ? 0 : Int(ccall(:u8_charnum, Csize_t, (Ptr{UInt8}, Csize_t),
                                       pointer(s), nextind(s, s.endof) - 1))
@@ -87,11 +85,6 @@ function isvalid(s::SubString, i::Integer)
     return (start(s) <= i <= endof(s)) && isvalid(s.string, s.offset+i)
 end
 
-isvalid(s::SubString{<:DirectIndexString}, i::Integer) = (start(s) <= i <= endof(s))
-
-ind2chr(s::SubString{<:DirectIndexString}, i::Integer) = begin checkbounds(s,i); i end
-chr2ind(s::SubString{<:DirectIndexString}, i::Integer) = begin checkbounds(s,i); i end
-
 nextind(s::SubString, i::Integer) = nextind(s.string, i+s.offset)-s.offset
 prevind(s::SubString, i::Integer) = prevind(s.string, i+s.offset)-s.offset
 
@@ -177,7 +170,6 @@ Julia
 ```
 """
 reverseind(s::AbstractString, i) = chr2ind(s, length(s) + 1 - ind2chr(reverse(s), i))
-reverseind(s::Union{DirectIndexString,SubString{DirectIndexString}}, i::Integer) = length(s) + 1 - i
 reverseind(s::RevString, i::Integer) = endof(s) - i + 1
 reverseind(s::SubString{String}, i::Integer) =
     reverseind(s.string, nextind(s.string, endof(s.string))-s.offset-s.endof+i-1) - s.offset

doc/src/manual/interacting-with-julia.md

@@ -91,15 +91,18 @@ search: AbstractString AbstractSparseMatrix AbstractSparseVector AbstractSet
 
   No documentation found.
 
-  Summary:
+  Summary
+  ≡≡≡≡≡≡≡≡≡
 
-  abstract AbstractString <: Any
+  abstract type AbstractString <: Any
 
-  Subtypes:
+  Subtypes
+  ≡≡≡≡≡≡≡≡≡≡
 
-  Base.Test.GenericString
-  DirectIndexString
+  Base.SubstitutionString
   String
+  SubString
+  Test.GenericString
 ```
 
 Help mode can be exited by pressing backspace at the beginning of the line.

test/core.jl

@@ -95,8 +95,8 @@ Type{Integer}  # cache this
 @test typejoin(Array{Float64},BitArray) <: AbstractArray
 @test typejoin(Array{Bool},BitArray) <: AbstractArray{Bool}
 @test typejoin(Tuple{Int,Int8},Tuple{Int8,Float64}) === Tuple{Signed,Real}
-@test Base.typeseq(typejoin(Tuple{String,String},Tuple{DirectIndexString,String},
-                            Tuple{String,DirectIndexString},Tuple{Int,String,Int}),
+@test Base.typeseq(typejoin(Tuple{String,String},Tuple{GenericString,String},
+                            Tuple{String,GenericString},Tuple{Int,String,Int}),
                    Tuple{Any,AbstractString,Vararg{Int}})
 @test Base.typeseq(typejoin(Tuple{Int8,Vararg{Int}},Tuple{Int8,Int8}),
                    Tuple{Int8,Vararg{Signed}})

test/strings/types.jl

@@ -146,7 +146,7 @@ end
 @test !ismatch(Regex("aa"), SubString("",1,0))
 @test ismatch(Regex(""), SubString("",1,0))
 
-# isvalid(), chr2ind() and ind2chr() for SubString{DirectIndexString}
+# isvalid(), chr2ind() and ind2chr() for SubString{String}
 let ss, s="lorem ipsum",
     sdict=Dict(SubString(s,1,11)=>s,
                SubString(s,1,6)=>"lorem ",