Path: utzoo!utgpu!attcan!uunet!mcvax!ukc!stc!idec!prlhp1!paszkows
From: paszkows@prlhp1.prl.philips.co.uk (paszkows)
Newsgroups: comp.sys.transputer
Subject: Re: Splitting up channel comms
Message-ID: <683@prlhp1.prl.philips.co.uk>
Date: 2 Nov 88 13:09:50 GMT
References: <675@prlhp1.prl.philips.co.uk>
Reply-To: paszkows@prlhp1.UUCP ()
Organization: Philips Research Laboratories, Redhill, UK
Lines: 54

In article <675@prlhp1.prl.philips.co.uk> paszkows@prlhp1.UUCP () writes:
>
>
>    chan.out ! lint1
>    chan.out ! lint2
>
>  
>  SEQ
>    chan.in  ? byte1
>    chan.in  ? int1 
>    chan.in  ? int2 
>    chan.in  ? byte2
>    chan.in  ? int3 
>
>

Having posed the problem, I have managed to solve it myself. Read on for the
solution.

Occam 2 reference manual states that with a PROTOCOL OF ANY, the data sent
is mapped into its constituent bytes, and output as an array.
Input on this channel inputs the array of bytes and converts ( by retyping
conversion ) the value to the type of the receiving variable.

I am not convinced that the last statement holds true ( opinions ? ) as I
had to do the retyping manually.

Anyway, on input channel, read the data into a BYTE array of length equal to
that of the sent data as shown below.

-- retype the bytes into required format.
BYTE byte1 RETYPES inword[5]
BYTE byte1 RETYPES inword[0] :
INT16 inta RETYPES [inword FROM 0 FOR 2 ]
INT16 intb RETYPES [inword FROM 3 FOR 2 ]
INT16 intc RETYPES [inword FROM 6 FOR 2 ]

INT32 int1, int2 :    -- the data being sent.

CHAN OF ANY channel.a :

SEQ
  PAR
    SEQ
      channel.a ! int1
      channel.a ! int2
    SEQ
      channel.a ? [ inword FROM 0 FOR 4 ]  -- receive 4 bytes making up int1
      channel.a ? [ inword FROM 4 FOR 4 ]  -- receive 4 bytes making up int2