make bind work with keyword functions

src/Curry.jl

@@ -7,6 +7,7 @@ export Bind, @bind
 Return a `Tuple` that interleaves `args` into the `nothing` slots of `slots`.
 
 ```jldoctest
+using Curry
 Curry.interleave((:a, nothing, :c, nothing), (12, 34))
 
 # output
@@ -17,6 +18,7 @@ Curry.interleave((:a, nothing, :c, nothing), (12, 34))
 Use `Some` to escape `nothing`
 
 ```jldoctest
+using Curry
 Curry.interleave((:a, Some(nothing), :c, nothing), (34,))
 
 # output
@@ -41,40 +43,52 @@ _interleave(firstbind::T, tailbind::Tuple, args::Tuple) where T = (
 
 """
 Represent a function call, with partially bound arguments.
+"""
+struct Bind{F, A, K} <: Function
+    f::F
+    a::A
+    k::K
+end
+
+function (c::Bind)(args...; kw...)
+    c.f(interleave(c.a, args)...; c.k..., kw...)
+end
 
+"""
+    `bind(f, a, b)`
+    `bind(f, args...; kw...)`
+
+The `bind` function partially evaluates `f` by binding some of its arguments.
+Positional arguments of `f` that should not be bound are indicated by passing `nothing`
+to `bind` at the respective position.
 ```jldoctest
-b = Bind(+, (1, 2))
-b()
+julia> using Curry: bind
 
-# output
+julia> b = bind(+, 1, 2); # no nothing, all arguments bound
 
+julia> b()
 3
-```
 
-```jldoctest
-b = Bind(*, ("hello", nothing))
-b(", world")
-
-# output
+julia> b = bind(*, "hello", nothing); # only first argument bound
 
+julia> b(", world")
 "hello, world"
-```
 
-`Bind(f, (g(), h()))` is like `:(f(g(), h()))` but `f` `g` and `h` are lexically scoped, and `g()` and `h()` are evaluated eagerly.
-"""
-struct Bind{F, A} <: Function
-    f::F
-    a::A
-end
+julia> b = bind(=>, nothing, 1); # second argument bound
 
-function (c::Bind)(args...)
-    c.f(interleave(c.a, args)...)
-end
+julia> b("one")
+"one" => 1
 
+julia> b = bind(isapprox, nothing, nothing, atol=100); # only atol keyword bound
+
+julia> b(10, 20)
+true
+
+julia> b(10, 20, atol=1) # keywords can be reassigned on the fly
+false
+```
 """
-`bind(f, a, b)` is equivalent to Bind(f, (a, b))
-"""
-bind(f, args...) = Bind(f, args)
+bind(f, args...; kw...) = Bind(f, args, kw)
 
 """
 `@bind f(a,b)` macroexpands to `bind(f, a, b)`
@@ -83,7 +97,7 @@ bind(f, args...) = Bind(f, args)
 macro bind(ex)
     ex.head == :call || error()
     # `ex.args[1]` is the function and `ex.args[2:end]` are the positional arguments
-    return :(bind($(map(esc, ex.args)...)))
+    return :($bind($(map(esc, ex.args)...)))
 end
 
 end

test/Project.toml

@@ -1,2 +1,3 @@
 [deps]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"

test/runtests.jl

@@ -1,6 +1,28 @@
 using Curry
+using Curry: bind
 using Test
 
+
+@testset "keywords" begin
+    @test bind(≈, 1, nothing, atol=1.1)(2)
+    @test bind(≈, 1, nothing, )(2, atol=1.1)
+    @test !bind(≈, 1, nothing, atol=1.1)(2, atol=0.9)
+    @test !bind(≈, 1, nothing, atol=0.9)(2)
+    @test bind(≈, 1, nothing, atol=0.9)(2, atol=1.1)
+    @test bind(≈, 1, nothing, atol=0.9)(2, atol=2)
+
+    @test bind(≈, nothing, nothing, atol=1.1)(1,2)
+    @test !bind(≈, nothing, nothing, atol=0.9)(1,2)
+    a2 = @inferred bind(≈, nothing, nothing)
+    b2 = @inferred bind(≈, nothing, nothing, atol=1)
+    c2 = @inferred bind(≈, nothing, nothing, atol=1, rtol=2)
+    a1 = @inferred bind(≈, 3, nothing, atol=1, rtol=2)
+    @inferred a2(1,2)
+    @inferred b2(1,2)
+    @inferred c2(1,2)
+    @inferred a1(1.0)
+end
+
 @testset "Bind.jl" begin
 
     #=
@@ -40,13 +62,16 @@ using Test
     @test eager == lazy
 
 
-    is3 = Bind(==, (3, nothing))
+    is3 = bind(==, 3, nothing)
     @test false == @inferred is3(4)
-    isnothing2 = Bind(===, (Some(nothing), nothing))
+    isnothing2 = Bind(===, (Some(nothing), nothing), ())
 
     @test isnothing2(nothing)
     @test isnothing2(:notnothing) == false
 
     b = @bind "hey" * nothing * "there"
     @test b(", you, ") == "hey, you, there"
 end
+
+using Documenter: doctest
+doctest(Curry)