Re: next "big" language?--New Pragmas

Re: next "big" language?--New Pragmas

[Robert C. Leif, Ph.D.]

From: Bob Leif
Ada_Med

Pragma Assert(x); and others have recently been discussed. This note
describes a very significant problem, which I hope will be solved by one of
the new proposed pragmas. The checking of units in scientific calculations
could be considered an early example of type checking. Bill Whitaker was
probably the first to try to solve this problem in Ada. Recently, (
Macpherson, 1996) proposed the traditional solution of initially compiling
his Scientific Dimensional Integrity Package and then if there is a
performance requirement reverting to another package which only performs the
numerical operations. Although this is obviously preferable to not doing
dimensional checking, the Ada compiler is limited in its ability to check
that the numeric processes of the two packages are identical.  It would be
preferable, if the Ada compiler could compile the Scientific Dimensional
Integrity Package or similar software and after checking that the types
including the units match, optimize out all or at least most of the unit
checking.

G. W. Macpherson, "A Reusable Ada Package for Scientific Dimensional
Integrity", ACM Ada LETTERS, Vol. XVI , Number 3, May/June 1996 pp.56-69.
Robert C. Leif, Ph.D., PMIAC,
Vice President & Research Director
Ada_Med, A Division of Newport Instruments
Tel. & Fax (619) 582-0437