Support get(::Function, ::EnvHash, key) (#430)

README.md

@@ -201,6 +201,8 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `IOContext` accepting key-value `Pair`s ([#23271]).
 
+* `get` do-block syntax supported when using `ENV` ([#23412]).
+
 ## Renaming
 
 
@@ -366,6 +368,7 @@ includes this fix. Find the minimum version from there.
 [#23051]: https://github.com/JuliaLang/julia/issues/23051
 [#23235]: https://github.com/JuliaLang/julia/issues/23235
 [#23271]: https://github.com/JuliaLang/julia/issues/23271
+[#23412]: https://github.com/JuliaLang/julia/issues/23412
 [#23427]: https://github.com/JuliaLang/julia/issues/23427
 [#23570]: https://github.com/JuliaLang/julia/issues/23570
 [#23666]: https://github.com/JuliaLang/julia/issues/23666

src/Compat.jl

@@ -853,6 +853,13 @@ end
     export Uninitialized, uninitialized
 end
 
+# 0.7.0-DEV.1499
+if VERSION < v"0.7.0-DEV.1499"
+    function Base.get(f::Base.Callable, ::Base.EnvHash, k::AbstractString)
+        Base.access_env(k->f(), k)
+    end
+end
+
 include("deprecated.jl")
 
 end # module Compat

test/runtests.jl

@@ -946,6 +946,12 @@ let A = [1]
     @test x == 1
 end
 
+# 0.7.0-DEV.1499
+let key = "TEST_23412"
+    @test !haskey(ENV, key)
+    @test get(() -> "default", ENV, key) == "default"
+end
+
 if VERSION < v"0.6.0"
     include("deprecated.jl")
 end