3 Sep
2018
3 Sep
'18
12:18 a.m.
On 9/2/18, Dave Horsfall <dave(a)horsfall.org> wrote:
I have never seen a full-blown PL/I compiler (only subsets), and I recall
being told that there never will be one because it is simply impossible,
given the spec.
Naturally I am happy to be proven wrong on this.
IBM had PL/I compilers for TOS, DOS, and OS on System/360, and for
DOS/VS and OS/VS on System/370. If those weren't full implementations
of the original spec, they were pretty close.
IBM PL/I had a good number of what I call toxic language features,
such as the DEFAULT statement (which was Fortran's IMPLICIT on
steroids). Most PL/I shops had as part of their coding standards a
set of language features banned from the code. The ANSI standard
eliminated a lot of these, although it also threw out some useful
features such as iSUB defining and by-name structure assignment.
One of my favourite features was sterling pictures, with pounds,
shillings, and pence fields (represented internally as a packed
decimal value in pence). Sterling pictures weren't finally deprecated
in the IBM PL/I compilers until 1979, IIRC.
-Paul W,.