From ab82f57d8d2c70bc92b0ad2f67597264bf7c56cc Mon Sep 17 00:00:00 2001
From: Katharine Hyatt <khyatt@flatironinstitute.org>
Date: Thu, 28 Feb 2019 12:27:28 -0600
Subject: [PATCH] Document AbstractDict and AbstractSet

---
 base/essentials.jl                         | 13 +++++++++++++
 doc/src/base/collections.md                |  2 ++
 doc/src/manual/conversion-and-promotion.md |  2 +-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/base/essentials.jl b/base/essentials.jl
index 122eb385f19de..719869d67a744 100644
--- a/base/essentials.jl
+++ b/base/essentials.jl
@@ -6,7 +6,20 @@ const Callable = Union{Function,Type}
 
 const Bottom = Union{}
 
+"""
+    AbstractSet{T}
+
+Supertype for set-like types whose elements are of type `T`.
+[`Set`](@ref), [`BitSet`](@ref) and other types are subtypes of this.
+"""
 abstract type AbstractSet{T} end
+
+"""
+    AbstractDict{K, V}
+
+Supertype for dictionary-like types with keys of type `K` and values of type `V`.
+[`Dict`](@ref), [`IdDict`](@ref) and other types are subtypes of this.
+"""
 abstract type AbstractDict{K,V} end
 
 # The real @inline macro is not available until after array.jl, so this
diff --git a/doc/src/base/collections.md b/doc/src/base/collections.md
index c070111d50a7c..2e5ad94307e84 100644
--- a/doc/src/base/collections.md
+++ b/doc/src/base/collections.md
@@ -191,6 +191,7 @@ for the key `x`).  Multiple arguments to `D[...]` are converted to tuples; for e
 `D[x,y]`  is equivalent to `D[(x,y)]`, i.e. it refers to the value keyed by the tuple `(x,y)`.
 
 ```@docs
+Base.AbstractDict
 Base.Dict
 Base.IdDict
 Base.WeakKeyDict
@@ -233,6 +234,7 @@ Partially implemented by:
 ## Set-Like Collections
 
 ```@docs
+Base.AbstractSet
 Base.Set
 Base.BitSet
 Base.union
diff --git a/doc/src/manual/conversion-and-promotion.md b/doc/src/manual/conversion-and-promotion.md
index baf2314dbcb9f..8a9c72ba3f26f 100644
--- a/doc/src/manual/conversion-and-promotion.md
+++ b/doc/src/manual/conversion-and-promotion.md
@@ -194,7 +194,7 @@ already of the requested type:
 convert(::Type{T}, x::T) where {T<:Number} = x
 ```
 
-Similar definitions exist for `AbstractString`, `AbstractArray`, and `AbstractDict`.
+Similar definitions exist for `AbstractString`, [`AbstractArray`](@ref), and [`AbstractDict`](@ref).
 
 ## Promotion