Add @something and @coalesce (#742)

Author: omus

Project.toml

@@ -1,6 +1,6 @@
 name = "Compat"
 uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
-version = "3.28.0"
+version = "3.29.0"
 
 [deps]
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"

README.md

@@ -54,6 +54,8 @@ changes in `julia`.
 
 ## Supported features
 
+* `@something` and `@coalesce` as short-circuiting versions of `something` and `coalesce` ([#40729]) (since Compat 3.29)
+
 * `NamedTuple(::Pairs)` ([#37454]) (since Compat 3.28)
 
 * `UUID(::UUID)` and `parse(::Type{UUID}, string)` ([#36018] / [#36199]) (since Compat 3.27)
@@ -242,3 +244,4 @@ Note that you should specify the correct minimum version for `Compat` in the
 [#36018]: https://github.com/JuliaLang/julia/pull/36018
 [#36199]: https://github.com/JuliaLang/julia/pull/36199
 [#37454]: https://github.com/JuliaLang/julia/pull/37454
+[#40729]: https://github.com/JuliaLang/julia/pull/40729

src/Compat.jl

@@ -894,6 +894,27 @@ if VERSION < v"1.6.0-DEV.877"
     Base.NamedTuple(itr) = (; itr...)
 end
 
+# https://github.com/JuliaLang/julia/pull/40729
+if VERSION < v"1.7.0-DEV.1088"
+    macro something(args...)
+        expr = :(nothing)
+        for arg in reverse(args)
+            expr = :((val = $arg) !== nothing ? val : $expr)
+        end
+        return esc(:(something(let val; $expr; end)))
+    end
+
+    macro coalesce(args...)
+        expr = :(missing)
+        for arg in reverse(args)
+            expr = :((val = $arg) !== missing ? val : $expr)
+        end
+        return esc(:(let val; $expr; end))
+    end
+
+    export @something, @coalesce
+end
+
 include("iterators.jl")
 include("deprecated.jl")
 

test/runtests.jl

@@ -884,3 +884,24 @@ end
     f(;kwargs...) = NamedTuple(kwargs)
     @test f(a=1, b=2) == (a=1, b=2)
 end
+
+# https://github.com/JuliaLang/julia/pull/40729
+@testset "@something" begin
+    @test_throws ArgumentError @something()
+    @test_throws ArgumentError @something(nothing)
+    @test @something(1) === 1
+    @test @something(Some(nothing)) === nothing
+
+    @test @something(1, error("failed")) === 1
+    @test_throws ErrorException @something(nothing, error("failed"))
+end
+
+@testset "@coalesce" begin
+    @test @coalesce() === missing
+    @test @coalesce(1) === 1
+    @test @coalesce(nothing) === nothing
+    @test @coalesce(missing) === missing
+
+    @test @coalesce(1, error("failed")) === 1
+    @test_throws ErrorException @coalesce(missing, error("failed"))
+end