Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!decwrl!pa.dec.com!src.dec.com!Dick Orgass <orgass+@rchland.ibm.com>
From: orgass+@rchland.ibm.com (Dick Orgass)
Newsgroups: comp.lang.modula3
Subject: Nit on Wr.i3
Message-ID: <Uc3B1wk91E444qTGMw@rchland.ibm.com>
Date: 17 Apr 91 22:47:24 GMT
Reply-To: "Dick Orgass" <orgass@ibm.com>
Lines: 25
To: m3

In one sense, this question is a real nit but there is a longer term
performance question behind the nit.

The procedures Wr.PutString and UnsafeWr.FastPutString are both declared
so that the second parameter, the ARRAY OF CHAR to be written is a value
parameter.  This forces the compiler to write code to copy the array
just to again copy it into the writer's buffer; the intermediate copy is
then destroyed.

By examining the code of the implementations of these procedures (in
WrMove.m3), it's easy to see that the actual parameters are not modified.

I propose that the declaration of these procedures be changed as follows:

In Wr:

    PROCEDURE PutString(wr: T; READONLY a: ARRAY OF CHAR)
        RAISES {Failure, Alerted, Error};

In UnsafeWr:

    PROCEDURE FastPutString(wr: Wr.T; READONLY a: ARRAY OF CHAR)
      RAISES {Failure, Alerted, Error};

Dick