restructure

src/NATS.jl

@@ -11,13 +11,75 @@ using BufferedStreams
 
 import Base: show, convert, close
 
-include("init.jl")
-include("consts.jl")
+const NATS_CLIENT_VERSION = "0.1.0"
+const NATS_CLIENT_LANG = "julia"
+const NATS_HOST = get(ENV, "NATS_HOST", "localhost")
+const NATS_PORT = parse(Int, get(ENV, "NATS_PORT", "4222"))
+const ERROR_THROTTLING_SECONDS = 5
+const DEFAULT_CONNECT_ARGS = (
+    verbose= false,
+    pedantic = false,
+    tls_required = false,
+    auth_token = nothing,
+    user = nothing,
+    pass = nothing,
+    name = nothing,
+    lang = NATS_CLIENT_LANG,
+    version = NATS_CLIENT_VERSION,
+    protocol = nothing,
+    echo = nothing,
+    sig = nothing,
+    jwt = nothing,
+    no_responders = true,
+    headers = true,
+    nkey = nothing
+)
+const OUTBOX_SIZE = 10000000
+const SOCKET_CONNECT_DELAYS = Base.ExponentialBackOff(n=1000, first_delay=0.5, max_delay=1)
+const SUBSCRIPTION_CHANNEL_SIZE = 10000
+
+const MIME_PROTOCOL = MIME"application/nats"
+const MIME_PAYLOAD  = MIME"application/nats-payload"
+const MIME_HEADERS  = MIME"application/nats-headers"
+
 include("protocol/protocol.jl")
 include("connection/connection.jl")
 include("pubsub/pubsub.jl")
 include("reqreply/reqreply.jl")
 
+function __init__()
+    Base.Experimental.register_error_hint(MethodError) do io, exc, argtypes, kwargs
+        if exc.f == convert && length(argtypes) > 1
+             # TODO: check if 2nd arg is Msg of Hmsg
+             print(io, """
+                       
+                       To use `$(argtypes[1])` as parameter of subscription handler apropriate conversion from `$(argtypes[2])` must be provided.
+                       ```
+                       import Base: convert
+
+                       function convert(::Type{$(argtypes[1])}, msg::Union{NATS.Msg, NATS.HMsg})
+                           # Implement conversion logic here.
+                       end
+
+                       ```
+                       """)
+        elseif exc.f == show
+            print(io, """
+                       
+                       Object of type `$(argtypes[3])` cannot be serialized into payload.
+                       ```
+                       import Base: show
+
+                       function Base.show(io::IO, NATS.MIME_PROTOCOL, x::$(argtypes[3]))
+                            # Write content to `io` here.
+                        end
+
+                       ```
+                       """)
+        end
+    end
+end
+
 export connect, ping, publish, subscribe, unsubscribe, payload, request, reply, header, headers, drain, isdrained
 
 end