Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!ux1.cso.uiuc.edu!milo.mcs.anl.gov!atlantis.ees.anl.gov!korp From: korp@atlantis.ees.anl.gov (Peter Korp) Newsgroups: comp.lang.postscript Subject: Re: A question about //add Message-ID: <1990Nov13.220516.14826@mcs.anl.gov> Date: 13 Nov 90 22:05:16 GMT References: <1990Nov12.195235.13908@light.uucp> <321@heaven.woodside.ca.us> Sender: news@mcs.anl.gov Organization: Advanced Computer Application Center, Argonne National Laboratory Lines: 53 Nntp-Posting-Host: atlantis.ees.anl.gov In article <321@heaven.woodside.ca.us> glenn@heaven.woodside.ca.us (Glenn Reid) writes: >In article <1990Nov12.195235.13908@light.uucp> bvs@BitBlocks.COM (Bakul Shah) writes: >>All versions of the (Adobe) PostScript interpreter since version >>25.0 provide an immediately evaluated name facility: When the >>scanner encounters a `//name' token, it immediately looks up the >>name in the current dictionary stack and substitutes the name's >>value for the name[%]. The effect is as if the `load' operator >>had been applied to the name (except that this happens in the >>scanner). >> >>Now the Question. If at the top level (i.e. not nested within >>any braces) the input is >> 1 2 //add >>should the operand stack contain >> 1 2 --add-- >>or >> 3 >>? You can test this by feeding >> 1 2 //add pstack clear >>to your PostScript interprter. >> >>My QMS PS 410 printer (running Adobe PostScript version 52.4) says >>the stack has 1 2 --add--. Initially I thought that was the >>correct behavior but L. Peter Deutsch , the >>author of Ghostscript, argues the stack should contain 3 and I >>agree with him now. > >Just as a data point, I tried your program on my (Adobe) Display >PostScript interpreter and got "3" on the stack: > > heaven> /usr/lib/NextStep/WindowServer -e start > PostScript(r) Version 1006.24 > PS>1 2 //add pstack > 3 > PS>quit > [talk of what should be left on stack deleted] As another point of reference, I trie it in OpenWindows and got: tripoli-> psh executive Welcome to X11/NeWS Version 2 1 2 //add stack 3 quit psh: NeWS server disconnected It is nice to see the PS interpreters agree about what to do! :-) Peter