Spaces around anonymous function heads (->), closes #7.

src/Runic.jl

@@ -293,6 +293,7 @@ function format_node!(ctx::Context, node::Node)::Union{Node, Nothing, NullNode}
     @return_something format_float_literals(ctx, node)
     @return_something spaces_around_operators(ctx, node)
     @return_something spaces_around_assignments(ctx, node)
+    @return_something spaces_around_anonymous_function(ctx, node)
     @return_something no_spaces_around_colon_etc(ctx, node)
     @return_something for_loop_use_in(ctx, node)
     @return_something four_space_indent(ctx, node)

src/runestone.jl

@@ -314,6 +314,14 @@ function spaces_around_assignments(ctx::Context, node::Node)
     return spaces_around_x(ctx, node, is_x)
 end
 
+function spaces_around_anonymous_function(ctx::Context, node::Node)
+    if !(kind(node) === K"->" && !is_leaf(node))
+        return nothing
+    end
+    is_x = x -> kind(x) === K"->"
+    return spaces_around_x(ctx, node, is_x)
+end
+
 # Opposite of `spaces_around_x`: remove spaces around `x`
 function no_spaces_around_x(ctx::Context, node::Node, is_x::F) where F
     @assert !is_leaf(node)

test/runtests.jl

@@ -198,6 +198,12 @@ end
     end
 end
 
+@testset "whitespace around ->" begin
+    for sp in ("", " ", "  ")
+        @test format_string("a$(sp)->$(sp)b") == "a -> b"
+    end
+end
+
 @testset "whitespace in comparison chains" begin
     for sp in ("", " ", "  ")
         @test format_string("a$(sp)==$(sp)b") == "a == b"