rename n_avail(Channel) to navailable()

+ docs & export

base/channels.jl

@@ -107,15 +107,18 @@ The maximal number of elements the channel can store.
 """
 capacity(c::Channel) = c.sz_max
 
-function n_avail(c::Channel)
+"""
+The number of elements currently in the channel.
+"""
+function navailable(c::Channel)
     if c.put_pos >= c.take_pos
         return c.put_pos - c.take_pos
     else
         return c.szp1 - c.take_pos + c.put_pos
     end
 end
 
-show(io::IO, c::Channel) = print(io, "$(typeof(c))(capacity:$(capacity(c)), sz_curr:$(n_avail(c)))")
+show(io::IO, c::Channel) = print(io, "$(typeof(c))(capacity:$(capacity(c)), navailable:$(navailable(c)))")
 
 start{T}(c::Channel{T}) = Ref{Nullable{T}}()
 function done(c::Channel, state::Ref)

base/exports.jl

@@ -1218,6 +1218,7 @@ export
     launch,
     manage,
     myid,
+    navailable,
     nprocs,
     nworkers,
     pmap,