Port implicit named tuple and keyword argument names (#747)

* Port implicit named tuple and keyword argument names

* Set version to 3.32.0

Project.toml

@@ -1,6 +1,6 @@
 name = "Compat"
 uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
-version = "3.31.1"
+version = "3.32.0"
 
 [deps]
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"

README.md

@@ -54,6 +54,8 @@ changes in `julia`.
 
 ## Supported features
 
+* Implicit keywords arguments or named tuples is supported using the `@compat` macro, e.g. `@compat f(; x, f.p)` and `@compat (; x, f.p)` is equivalent to `f(; x=x, p=f.p)` and `(; x=x, p=f.p)` respectively. ([#34331]) (since Compat 3.32.0)
+
 * Two argument methods `findmax(f, domain)`, `argmax(f, domain)` and the corresponding `min` versions ([#35316], [#41076]) (since Compat 3.31.1)
 
 * `isunordered(x)` returns true if `x` is value that is normally unordered, such as `NaN` or `missing` ([#35316]) (since Compat 3.31.1)
@@ -258,3 +260,4 @@ Note that you should specify the correct minimum version for `Compat` in the
 [#41032]: https://github.com/JuliaLang/julia/pull/41032
 [#35316]: https://github.com/JuliaLang/julia/pull/35316
 [#41076]: https://github.com/JuliaLang/julia/pull/41076
+[#34331]: https://github.com/JuliaLang/julia/pull/34331

src/compatmacro.jl

@@ -8,6 +8,14 @@ function _compat(ex::Expr)
         # Passthrough
         return ex
     end
+
+    # https://github.com/JuliaLang/julia/pull/34331
+    @static if VERSION < v"1.5.0-DEV.499"
+        if ex.head === :call || ex.head === :tuple
+            ex = _assign_implicit_keywords(ex)
+        end
+    end
+
     return Expr(ex.head, map(_compat, ex.args)...)
 end
 
@@ -66,3 +74,23 @@ function _create_import_expression(path_aliases::Vector{Pair{Vector{Symbol}, Sym
     return_expr = Expr(:toplevel, module_expr, const_exprs..., nothing)
     return return_expr
 end
+
+function _assign_implicit_keywords(ex::Expr)
+    kwargs = if ex.head === :call && Meta.isexpr(ex.args[2], :parameters)
+        ex.args[2].args
+    elseif ex.head === :tuple && Meta.isexpr(ex.args[1], :parameters)
+        ex.args[1].args
+    else
+        []
+    end
+
+    for (i, k) in enumerate(kwargs)
+        if k isa Symbol
+            kwargs[i] = Expr(:kw, k, k)
+        elseif Meta.isexpr(k, :.)
+            kwargs[i] = Expr(:kw, k.args[2].value, k)
+        end
+    end
+
+    return ex
+end

test/runtests.jl

@@ -1068,3 +1068,22 @@ end
          @test get(() -> c[]+=1, x, (3,2,1)) == 3
     end
 end
+
+# https://github.com/JuliaLang/julia/pull/34331
+struct X
+    x
+end
+
+@testset "implicit keywords" begin
+    f(; x=0) = x
+    x = 1
+    s = X(2)
+    nested = X(X(3))
+
+    @test (@compat f(; x)) == 1
+    @test (@compat f(; s.x)) == 2
+    @test (@compat f(; nested.x.x)) == 3
+    @test (@compat (; x)) == (; x=1)
+    @test (@compat (; s.x)) == (; x=2)
+    @test (@compat (; nested.x.x)) == (; x=3)
+end