Escape more narrowly in @message

src/kwdef.jl

@@ -0,0 +1,122 @@
+isexpr(@nospecialize(ex), head::Symbol) = isa(ex, Expr) && ex.head === head
+
+macro kwdef(expr)
+ expr = macroexpand(__module__, expr) # to expand @static
+ isexpr(expr, :struct) || error("Invalid usage of @kwdef")
+ T = expr.args[2]
+ if T isa Expr && T.head === :<:
+ T = T.args[1]
+ end
+
+ params_ex = Expr(:parameters)
+ call_args = Any[]
+
+ _kwdef!(expr.args[3], params_ex.args, call_args)
+ # Only define a constructor if the type has fields, otherwise we'll get a stack
+ # overflow on construction
+ if !isempty(params_ex.args)
+ T_no_esc,_ = strip_esc(T)
+ if T_no_esc isa Symbol
+ sig = :(($(esc(T)))($params_ex))
+ call = :(($(esc(T)))($(call_args...)))
+ body = Expr(:block, __source__, call)
+ kwdefs = Expr(:function, sig, body)
+ elseif isexpr(T_no_esc, :curly)
+ # if T == S{A<:AA,B<:BB}, define two methods
+ # S(...) = ...
+ # S{A,B}(...) where {A<:AA,B<:BB} = ...
+ S = T.args[1]
+ P = T.args[2:end]
+ Q = Any[isexpr(U, :<:) ? U.args[1] : U for U in P]
+ SQ = :($S{$(Q...)})
+ body1 = Expr(:block, __source__, :(($(esc(S)))($(call_args...))))
+ sig1 = :(($(esc(S)))($params_ex))
+ def1 = Expr(:function, sig1, body1)
+ body2 = Expr(:block, __source__, :(($(esc(SQ)))($(call_args...))))
+ sig2 = :(($(esc(SQ)))($params_ex) where {$(esc.(P)...)})
+ def2 = Expr(:function, sig2, body2)
+ kwdefs = Expr(:block, def1, def2)
+ else
+ @show T_no_esc
+ error("Invalid usage of @kwdef")
+ end
+ else
+ kwdefs = nothing
+ end
+ return quote
+ $(esc(:($Base.@__doc__ $expr)))
+ $kwdefs
+ end
+end
+
+# @kwdef helper function
+# mutates arguments inplace
+function _kwdef!(blk, params_args, call_args, esc_count = 0)
+ for i in eachindex(blk.args)
+ ei = blk.args[i]
+ if ei isa Symbol
+ # var
+ push!(params_args, ei)
+ push!(call_args, ei)
+ elseif ei isa Expr
+ is_atomic = ei.head === :atomic
+ ei = is_atomic ? first(ei.args) : ei # strip "@atomic" and add it back later
+ is_const = ei.head === :const
+ ei = is_const ? first(ei.args) : ei # strip "const" and add it back later
+ # Note: `@atomic const ..` isn't valid, but reconstruct it anyway to serve a nice error
+ if ei isa Symbol
+ # const var
+ push!(params_args, ei)
+ push!(call_args, ei)
+ elseif ei.head === :(=)
+ lhs = ei.args[1]
+ lhs_no_esc, lhs_esc_count = strip_esc(lhs)
+ if lhs_no_esc isa Symbol
+ # var = defexpr
+ var = lhs_no_esc
+ elseif lhs_no_esc isa Expr && lhs_no_esc.head === :(::) && strip_esc(lhs_no_esc.args[1])[1] isa Symbol
+ # var::T = defexpr
+ var = strip_esc(lhs_no_esc.args[1])[1]
+ else
+ # something else, e.g. inline inner constructor
+ # F(...) = ...
+ continue
+ end
+ defexpr = ei.args[2] # defexpr
+ defexpr = wrap_esc(defexpr, esc_count + lhs_esc_count)
+ push!(params_args, Expr(:kw, var, esc(defexpr)))
+ push!(call_args, var)
+ lhs = is_const ? Expr(:const, lhs) : lhs
+ lhs = is_atomic ? Expr(:atomic, lhs) : lhs
+ blk.args[i] = lhs # overrides arg
+ elseif ei.head === :(::) && strip_esc(ei.args[1])[1] isa Symbol
+ # var::Typ
+ var,_ = strip_esc(ei.args[1])
+ push!(params_args, var)
+ push!(call_args, var)
+ elseif ei.head === :block
+ # can arise with use of @static inside type decl
+ _kwdef!(ei, params_args, call_args)
+ elseif ei.head === :escape
+ _kwdef!(ei, params_args, call_args, esc_count + 1)
+ end
+ end
+ end
+ blk
+end
+
+function strip_esc(expr)
+ count = 0
+ while isexpr(expr, :escape)
+ expr = expr.args[1]
+ count += 1
+ end
+ return (expr, count)
+end
+
+function wrap_esc(expr, count)
+ for _ = 1:count
+ expr = esc(expr)
+ end
+ return expr
+end

src/msg.jl

@@ -29,6 +29,8 @@ Return the fully qualified class name of a message.
 """
 function classname end
 
+include("kwdef.jl")
+
 function _message(classname, perf, sdef)
  if @capture(sdef, struct T_ <: P_ fields__ end)
  if T == P
@@ -37,32 +39,38 @@ function _message(classname, perf, sdef)
  else
  extra = :()
  end
- push!(fields, :(messageID::String = string(Fjage.uuid4())))
+ T = esc(T)
+ P = esc(P)
+ fields .= esc.(fields)
+ extra = esc(extra)
+ push!(fields, :(messageID::String = string(uuid4())))
  push!(fields, :(performative::Symbol = $perf))
- push!(fields, :(sender::Union{Fjage.AgentID,Nothing} = nothing))
- push!(fields, :(recipient::Union{Fjage.AgentID,Nothing} = nothing))
+ push!(fields, :(sender::Union{AgentID,Nothing} = nothing))
+ push!(fields, :(recipient::Union{AgentID,Nothing} = nothing))
  push!(fields, :(inReplyTo::Union{String,Nothing} = nothing))
  push!(fields, :(sentAt::Int64 = 0))
  quote
- Base.@kwdef mutable struct $(T) <: $(P); $(fields...); end
+ @kwdef mutable struct $(T) <: $(P); $(fields...); end
  Fjage.classname(::Type{$(T)}) = $(classname)
  Fjage.classname(::$(T)) = $(classname)
  Fjage._messageclasses[$(classname)] = $(T)
  $extra
- end |> esc
+ end
  elseif @capture(sdef, struct T_ fields__ end)
- push!(fields, :(messageID::String = string(Fjage.uuid4())))
+ T = esc(T)
+ fields .= esc.(fields)
+ push!(fields, :(messageID::String = string(uuid4())))
  push!(fields, :(performative::Symbol = $perf))
- push!(fields, :(sender::Union{Fjage.AgentID,Nothing} = nothing))
- push!(fields, :(recipient::Union{Fjage.AgentID,Nothing} = nothing))
+ push!(fields, :(sender::Union{AgentID,Nothing} = nothing))
+ push!(fields, :(recipient::Union{AgentID,Nothing} = nothing))
  push!(fields, :(inReplyTo::Union{String,Nothing} = nothing))
  push!(fields, :(sentAt::Int64 = 0))
  quote
- Base.@kwdef mutable struct $(T) <: Fjage.Message; $(fields...); end
+ @kwdef mutable struct $(T) <: Message; $(fields...); end
  Fjage.classname(::Type{$(T)}) = $(classname)
  Fjage.classname(::$(T)) = $(classname)
  Fjage._messageclasses[$(classname)] = $(T)
- end |> esc
+ end
  else
  @error "Bad message definition"
  end