Re: Evolution of PL/I

robin wrote:
.... various others quoted here ...
FOREVER adds no functioanlity to the language other than creating a
synonym of sorts. The parser doen't need to be extended to support it

To an extent, that's true, but then you lose the requirement that
no words are reserved, and once 'FOREVER' or any other
such word is set up that way, it cannot be used as an identifier.
you use it.

I've mostly avoided this discussion, but FOREVER in this context is a keyword like any other PL/I keyword and need no be reserved. If the syntax was "DO WHILE(FOREVER);" you'd have a problem.

Do you like UPTHRU?
Having just implemented DO ...BY <expression> when the <expression> is not a constant, I can see where UPTHRU and DOWNTHRU can save a fair amount of code. If the programmer knows which way the loop is running (as s/he usually does) this keeps the compiler from having to check the sign of the BY expression each time thru the loop to determine which of two jump instructions to execute to exit the loop.

.

Relevant Pages

  • highmem problem?
    ... Using 3 I/O APICs ... Calibrating delay loop... ... Enabling fast FPU save and restore... ... Linux Plug and Play Support v0.97 Adam Belay ...
    (Linux-Kernel)
  • Re: FileCopy vs. Read & Write or CopyFile API
    ... I like Jialiang's solution to loop whiel there is an error copying the file, ... Dim errNum as Integer ... Microsoft Online Community Support ... where an initial response from the community or a Microsoft Support ...
    (microsoft.public.vb.general.discussion)
  • Re: NV_vertex_program2 vs NV_vertex_program
    ... When I replace "CAL" instruction in a loop, by it's code, the program ... check if the card support Vertex Program 2 in the "right" way - should I ... MOV o, R0; ...
    (comp.graphics.api.opengl)
  • WARNINGs while compiling.
    ... WARNING: Module ... due to loop ... # ACPI Support ... # AX.25 network device drivers ...
    (Linux-Kernel)
  • Re: 2.6.16-rc1-mm4
    ... >> WARNING: Loop detected: ... >> WARNING: Module ... but I think it might be due having included kgdb support. ... # Device Drivers ...
    (Linux-Kernel)