Move eachregion implementation to Base

This is part of the effort to adjust the Base/stdlib split to resolve
the type piracy and invalidation headaches.

The Base counterpart to this commit is JuliaLang/julia@a5e0eabfdbec.

Author: tecosaur

docs/src/internals.md

@@ -15,8 +15,6 @@ StyledStrings.Legacy.RENAMED_COLORS
 StyledStrings.Legacy.legacy_color
 StyledStrings.Legacy.load_env_colors!
 StyledStrings.ansi_4bit_color_code
-StyledStrings.eachregion
-StyledStrings.annotation_events
 StyledStrings.face!
 StyledStrings.getface
 StyledStrings.loadface!

src/StyledStrings.jl

@@ -2,7 +2,7 @@
 
 module StyledStrings
 
-using Base: AnnotatedString, AnnotatedChar, AnnotatedIOBuffer, annotations, annotate!, annotatedstring
+using Base: AnnotatedString, AnnotatedChar, AnnotatedIOBuffer, annotations, annotate!, annotatedstring, eachregion
 using Base.ScopedValues: ScopedValue, with, @with
 
 # While these are imported from Base, we claim them as part of the `StyledStrings` API.
@@ -12,7 +12,6 @@ export @styled_str
 public Face, addface!, withfaces, styled, SimpleColor
 
 include("faces.jl")
-include("regioniterator.jl")
 include("io.jl")
 include("styledmarkup.jl")
 include("legacy.jl")

src/regioniterator.jl

@@ -3,7 +3,7 @@
 using Test
 
 using StyledStrings: StyledStrings, Legacy, SimpleColor, FACES, Face,
-    @styled_str, styled, StyledMarkup, eachregion, getface, addface!, loadface!, resetfaces!,
+    @styled_str, styled, StyledMarkup, getface, addface!, loadface!, resetfaces!,
     AnnotatedString, AnnotatedChar, AnnotatedIOBuffer, annotations
 using .StyledMarkup: MalformedStylingMacro
 
@@ -35,54 +35,6 @@ end
 # When tested as part of the stdlib, the package prefix can start appearing in show methods.
 choppkg(s::String) = chopprefix(s, "StyledStrings.")
 
-@testset "Eachregion" begin
-    annregions(str::String, annots::Vector{<:Tuple{UnitRange{Int}, Symbol, <:Any}}) =
-        [(s, Tuple.(a)) for (s, a) in eachregion(AnnotatedString(str, annots))]
-    # Regions that do/don't extend to the left/right edges
-    @test annregions(" abc ", [(2:4, :face, :bold)]) ==
-        [(" ", []),
-         ("abc", [(:face, :bold)]),
-         (" ", [])]
-    @test annregions(" x ", [(2:2, :face, :bold)]) ==
-        [(" ", []),
-         ("x", [(:face, :bold)]),
-         (" ", [])]
-    @test annregions(" x", [(2:2, :face, :bold)]) ==
-        [(" ", []),
-         ("x", [(:face, :bold)])]
-    @test annregions("x ", [(1:1, :face, :bold)]) ==
-        [("x", [(:face, :bold)]),
-         (" ", [])]
-    @test annregions("x", [(1:1, :face, :bold)]) ==
-        [("x", [(:face, :bold)])]
-    # Overlapping/nested regions
-    @test annregions(" abc ", [(2:4, :face, :bold), (3:3, :face, :italic)]) ==
-        [(" ", []),
-         ("a", [(:face, :bold)]),
-         ("b", [(:face, :bold), (:face, :italic)]),
-         ("c", [(:face, :bold)]),
-         (" ", [])]
-    @test annregions("abc-xyz", [(1:7, :face, :bold), (1:3, :face, :green), (4:4, :face, :yellow), (4:7, :face, :italic)]) ==
-        [("abc", [(:face, :bold), (:face, :green)]),
-         ("-", [(:face, :bold), (:face, :yellow), (:face, :italic)]),
-         ("xyz", [(:face, :bold), (:face, :italic)])]
-    # Preserving annotation order
-    @test annregions("abcd", [(1:3, :face, :red), (2:2, :face, :yellow), (2:3, :face, :green), (2:4, :face, :blue)]) ==
-        [("a", [(:face, :red)]),
-         ("b", [(:face, :red), (:face, :yellow), (:face, :green), (:face, :blue)]),
-         ("c", [(:face, :red), (:face, :green), (:face, :blue)]),
-         ("d", [(:face, :blue)])]
-    @test annregions("abcd", [(2:4, :face, :blue), (1:3, :face, :red), (2:3, :face, :green), (2:2, :face, :yellow)]) ==
-        [("a", [(:face, :red)]),
-         ("b", [(:face, :blue), (:face, :red), (:face, :green), (:face, :yellow)]),
-         ("c", [(:face, :blue), (:face, :red), (:face, :green)]),
-         ("d", [(:face, :blue)])]
-    # Region starting after a character spanning multiple codepoints.
-    @test annregions("𝟏x", [(1:4, :face, :red)]) ==
-        [("𝟏", [(:face, :red)]),
-         ("x", [])]
-end
-
 @testset "SimpleColor" begin
     @test SimpleColor(:hey).value == :hey # no error
     @test SimpleColor(0x01, 0x02, 0x03).value == (r=0x01, g=0x02, b=0x03)