Merge pull request #9 from JuliaLang/sjk/at-compat

Add ＠compat as discussed in #8

src/Compat.jl

@@ -1,4 +1,5 @@
 module Compat
+using Base.Meta
 
 if VERSION < v"0.4.0-dev+980"
     macro Dict(pairs...)
@@ -16,4 +17,42 @@ else
     end
 end
 
+function rewrite_dict(ex)
+    length(ex.args) == 1 && return ex
+
+    f = ex.args[1]
+    if isexpr(f, :curly)
+        newex = Expr(:typed_dict, :($(f.args[2])=>$(f.args[3])))
+    else
+        newex = Expr(:dict)
+    end
+
+    for i = 2:length(ex.args)
+        pair = ex.args[i]
+        !isexpr(pair, :(=>)) && return ex
+        push!(newex.args, pair)
+    end
+    newex
+end
+
+function _compat!(ex::Expr)
+    if ex.head == :call
+        f = ex.args[1]
+        if VERSION < v"0.4.0-dev+980" && (f == :Dict || (isexpr(f, :curly) && length(f.args) == 3 && f.args[1] == :Dict))
+            return rewrite_dict(ex)
+        end
+    end
+    for i = 1:length(ex.args)
+        ex.args[i] = _compat!(ex.args[i])
+    end
+    ex
+end
+_compat!(ex) = ex
+
+macro compat(ex)
+    esc(_compat!(ex))
+end
+
+export @compat
+
 end # module

test/runtests.jl

@@ -8,7 +8,35 @@ d[1] = 1
 @test Compat.@Dict(1 => 1) == d
 @test Compat.@Dict(1 => v) == d
 
+@test typeof(@compat(Dict(1 => 1))) == Dict{Int,Int}
+@test @compat(Dict(1 => 1)) == d
+@test @compat(Dict(1 => v)) == d
+
 ad = Dict{Any,Any}()
 ad[1] = 1
 @test Compat.@AnyDict(1 => 1) == ad
 @test Compat.@AnyDict(1 => v) == ad
+
+@test typeof(@compat(Dict{Any,Any}(1 => 1))) == Dict{Any,Any}
+@test @compat(Dict{Any,Any}(1 => 1)) == ad
+@test @compat(Dict{Any,Any}(1 => v)) == ad
+
+td = Dict{Int,Float64}()
+td[1] = 1.0
+
+@test typeof(@compat(Dict{Int,Float64}(1 => 1))) == Dict{Int,Float64}
+@test @compat(Dict{Int,Float64}(1 => 1)) == td
+@test @compat(Dict{Int,Float64}(1 => v)) == td
+
+@test @compat(Dict()) == Dict()
+@test @compat(Dict{Any,Any}()) == Dict{Any,Any}()
+@test @compat(Dict([(1, 1)])) == Dict([(1, 1)])
+
+@compat function f()
+	a = :a
+	b = :b
+	c = :c
+	d = :d
+	Dict(a => b, c => d)
+end
+@test f() == Dict([(:a, :b), (:c, :d)])