How do you match on Pair?

[jpfairbanks]

I thought this would work and the documentation doesn't have any examples of using Base.Pair as a pattern.

using MLStyle
s = 2=>3

@match s begin
  (a,b)  => a
  (a=>b) => b
end

The tuple line works fine, but then the pair line gives the following error on [d8e11817] MLStyle v0.4.17

ERROR: LoadError: PatternCompilationError(:(#= Untitled-2:7 =#), MethodError(MLStyle.MatchImpl.pattern_uncall, (Pair, MLStyle.MatchImpl.ModuleBoundedEx2tf(Main), Any[], Any[], Any[:(s::Symbol), :(v::Any)]), 0x00000000000082b5))
Stacktrace:
  [1] gen_match(val::Symbol, tbl::Expr, __source__::LineNumberNode, __module__::Module)
    @ MLStyle.MatchImpl ~/.julia/packages/MLStyle/SLOsr/src/MatchImpl.jl:712
  [2] var"@match"(__source__::LineNumberNode, __module__::Module, val::Any, tbl::Any)
    @ MLStyle.MatchImpl ~/.julia/packages/MLStyle/SLOsr/src/MatchImpl.jl:667
  [3] eval

Replacing (a=>b) with Pair(a,b) doesn't fix it.

[thautwarm]

Pair is not yet marked as a builtin pattern due to some unsolved design issues. You can try adding support in one line:

MLStyle.@as_record Pair

#= 
@match value begin
    (p1 => p2) => v  # or Pair(p1, p2) => v
end
=#
@match (1=>2) begin
    (a, b) => a + b
end