From 4cec44267d04dfd88460b6b6756ca2712438693a Mon Sep 17 00:00:00 2001
From: Lyndon White <lyndon.white@invenialabs.co.uk>
Date: Mon, 16 Mar 2020 18:12:44 +0000
Subject: [PATCH 1/4] add contains

---
 base/exports.jl        |  1 +
 base/strings/search.jl |  2 ++
 base/strings/util.jl   | 38 ++++++++++++++++++++++++++++++++++++++
 test/strings/search.jl |  7 +++++++
 4 files changed, 48 insertions(+)

diff --git a/base/exports.jl b/base/exports.jl
index 6754fe08b3079..335820b3000bf 100644
--- a/base/exports.jl
+++ b/base/exports.jl
@@ -439,6 +439,7 @@ export
     zeros,
 
 # search, find, match and related functions
+    contains,
     eachmatch,
     endswith,
     findall,
diff --git a/base/strings/search.jl b/base/strings/search.jl
index 15d0a968a0226..dbc572dc948fa 100644
--- a/base/strings/search.jl
+++ b/base/strings/search.jl
@@ -526,6 +526,8 @@ true
 julia> occursin(r"a.a", "abba")
 false
 ```
+
+See also: [`contains`](@ref).
 """
 occursin(needle::Union{AbstractString,AbstractChar}, haystack::AbstractString) =
     _searchindex(haystack, needle, firstindex(haystack)) != 0
diff --git a/base/strings/util.jl b/base/strings/util.jl
index 22dee5ebd024a..584ea3ae5831d 100644
--- a/base/strings/util.jl
+++ b/base/strings/util.jl
@@ -70,6 +70,29 @@ function endswith(a::Union{String, SubString{String}},
     end
 end
 
+"""
+    contains(haystack::AbstractString, needle)
+
+Return `true` if `haystack` contains `needle`.
+This is the same as `occursin(needle, haystack)`, but is provided for consistency with
+`startswith(haystack, needle)` and `endswith(haystack, needle)`.
+
+# Examples
+```jldoctest
+julia> contains("JuliaLang is pretty cool!", "Julia")
+true
+
+julia> contains("JuliaLang is pretty cool!", 'a')
+true
+
+julia> contains("aba", r"a.a")
+true
+
+julia> contains("abba", r"a.a")
+false
+"""
+contains(haystack::AbstractString, needle) = occursin(needle, haystack)
+
 """
     endswith(suffix)
 
@@ -100,6 +123,21 @@ used to implement specialized methods.
 """
 startswith(s) = Base.Fix2(startswith, s)
 
+"""
+    contains(needle)
+
+Create a function that checks whether its argument contains `needle`, i.e.
+a function equivalent to `haystack -> contains(haystack, needle)`.
+
+The returned function is of type `Base.Fix2{typeof(contains)}`, which can be
+used to implement specialized methods.
+
+!!! compat "Julia 1.5"
+    The single argument `contains(needle)` requires at least Julia 1.5.
+
+"""
+contains(needle) = Base.Fix2(contains, needle)
+
 """
     chop(s::AbstractString; head::Integer = 0, tail::Integer = 1)
 
diff --git a/test/strings/search.jl b/test/strings/search.jl
index 8de73e5c652e5..92fc03177dc76 100644
--- a/test/strings/search.jl
+++ b/test/strings/search.jl
@@ -356,6 +356,13 @@ end
 @test occursin("o", "foo")
 @test occursin('o', "foo")
 
+# contains
+@test contains("foo", "o")
+@test contains("foo", 'o')
+# contains in curried form
+@test contains("o")("foo")
+@test contains('o')("foo")
+
 @test_throws ErrorException "ab" ∈ "abc"
 
 # issue #15723

From e109abb27c2e5302273d3216b448fe221e85d306 Mon Sep 17 00:00:00 2001
From: Lyndon White <lyndon.white@invenialabs.co.uk>
Date: Mon, 16 Mar 2020 18:47:30 +0000
Subject: [PATCH 2/4] add contains to News.md

---
 NEWS.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/NEWS.md b/NEWS.md
index aedf39a84cad1..a7dc3f3d66855 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -75,6 +75,7 @@ New library functions
 * New function `bitreverse` for reversing the order of bits in a fixed-width integer ([#34791]).
 * New function `bitrotate(x, k)` for rotating the bits in a fixed-width integer ([#33937]).
 * One argument methods `startswith(x)` and `endswith(x)` have been added, returning partially-applied versions of the functions, similar to existing methods like `isequal(x)` ([#33193]).
+* New function `contains(haystack, needle)` and its one argument partially applied form have been added, it acts like `occursin(needle, haystack)`([#35132]).
 
 New library features
 --------------------

From 077f83d42037a0931d42c0678809c09ea0e7e235 Mon Sep 17 00:00:00 2001
From: Lyndon White <lyndon.white@invenialabs.co.uk>
Date: Tue, 17 Mar 2020 10:43:20 +0000
Subject: [PATCH 3/4] Add contains to docs

---
 doc/src/base/strings.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/doc/src/base/strings.md b/doc/src/base/strings.md
index 12da6d950abaf..22943329af501 100644
--- a/doc/src/base/strings.md
+++ b/doc/src/base/strings.md
@@ -53,6 +53,7 @@ Base.lstrip
 Base.rstrip
 Base.startswith
 Base.endswith
+Base.contains
 Base.first(::AbstractString, ::Integer)
 Base.last(::AbstractString, ::Integer)
 Base.uppercase

From d742c7a7409765567b6ad1154e8a72f9adf80030 Mon Sep 17 00:00:00 2001
From: Lyndon White <lyndon.white@invenialabs.co.uk>
Date: Mon, 23 Mar 2020 10:14:00 +0000
Subject: [PATCH 4/4] put compat note on first mention of function

---
 base/strings/util.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/base/strings/util.jl b/base/strings/util.jl
index 584ea3ae5831d..14fc530dfcd7e 100644
--- a/base/strings/util.jl
+++ b/base/strings/util.jl
@@ -90,6 +90,10 @@ true
 
 julia> contains("abba", r"a.a")
 false
+```
+
+!!! compat "Julia 1.5"
+    The `contains` function requires at least Julia 1.5.
 """
 contains(haystack::AbstractString, needle) = occursin(needle, haystack)
 
@@ -131,10 +135,6 @@ a function equivalent to `haystack -> contains(haystack, needle)`.
 
 The returned function is of type `Base.Fix2{typeof(contains)}`, which can be
 used to implement specialized methods.
-
-!!! compat "Julia 1.5"
-    The single argument `contains(needle)` requires at least Julia 1.5.
-
 """
 contains(needle) = Base.Fix2(contains, needle)