# Talk:PostScript

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## is ps a really a programming language???

I don't thing ps is a programming language!

I don't think you've tried writing it by hand, otherwise you would know it's a programming language. --Zundark 15:21, 20 Jun 2004 (UTC)
Yeah, Go and look at Fibonacci number program's PS example. Dysprosia 22:52, 20 Jun 2004 (UTC)
Or the PS-HTTPD [1].
It really is! And it's crappy – except when printing things. Said: Rursus 14:09, 2 June 2007 (UTC)

There is no question that PostScript is a real programming language. It is Turing-complete, and furthermore it can do console I/O and file I/O, and it does graphics Really Well. It is not a markup language like HTML, XML, SGML, TeX, LaTeX, or PDF. Those languages are not Turing-complete (to the best of my knowledge, although TeX/LaTeX may be).

TeX is indeed Turing-complete. Knuth wrote a macro (it's in the TeXbook somewhere) so that you could type \primes{n} and get the first n primes, which is pretty impressive. grendel|khan 20:54, 2005 Apr 7 (UTC)

Can some language history expert please tell (and substantiate) whether PostScript design is just similar to Forth or was it derived from it to some extent? BACbKA 10:40, 25 Sep 2004 (UTC)

They're both stack based programming languages, so they're bound to look similar. The RPN style was chosen since it's supposed to be optimised for machine handling. Dysprosia 10:48, 25 Sep 2004 (UTC)
Answering my own question: according to [2], the design was a little bit influenced, but the implementation paradigm was completely independent. BACbKA 12:52, 25 Sep 2004 (UTC)

According to http://www.c2.com/cgi/wiki?ForthPostscriptRelationship PostScript was indeed influenced by Forth. I think Forths influence on PostScript is much more obvious, than a lot of other influences between languages statet on wikipedia. 89.245.208.7 (talk) 13:25, 20 December 2008 (UTC)

c2.com is not an authorative source, I've seen a lot of bias and speculation there. If you read the first edition of the PostScript Language Reference Manual you will see that the authors explicitely say that PostScript was not influenced by Forth: Page vii, PostScript Language Reference Manual: "Design System language and its successors (PostScript) bear a superficial resemblance to the FORTH programming language, their conception and development wer entirely independant of FORTH."

It's no more influenced by FORTH than it is influenced by Lisp. Jeffz1 (talk) —Preceding undated comment was added at 07:46, 21 December 2008 (UTC).

From the "PostScript® LANGUAGE REFERENCE third edition" - Adobe Systems Incorporated: "Like all programming languages, the PostScript language builds on elements and ideas from several of the great programming languages. The syntax most closely resembles that of the programming language FORTH. It incorporates a postfix notation in which operators are preceded by their operands. The number of spe- cial characters is small and there are no reserved words.". This is an official document and must surely count as an authoritative source, therefore I will add FORTH as an influence. — Preceding unsigned comment added by 198.8.67.3 (talk) 15:41, 23 August 2013 (UTC)

## PostScript origins

"The language had its beginnings in 1976 at the Evans & Sutherland Computer Corporation, where it was known as the `Design System'... Although the Design System language and its successors bear a superficial resemblance to the FORTH programming language, their conception and development were entirely independent of FORTH."

Postscript language reference manual, Adobe Systems Incorporated, 1985

Is there any point in incorporating any of this information? --Rpresser 06:07, 11 March 2006 (UTC)

## John Gaffney ???

A "John Gaffney" is mentioned in one of the first paragraphs. Vandalism, or just an unexplained name ?

-- Cmskog 11:39, 3 October 2005 (UTC)

FOLDOC and others claim he was a big guy at Evans & Sutherland; sounds reasonable to me.
Atlant 19:01, 3 October 2005 (UTC)
In any case, it links to the wrong page. Is he a notable person? I am removing the wikilink, and if someone feels he is important enough, they can make a page on him. Masud 03:42, 31 March 2006 (UTC)
As of this writing, John Gaffney is a senior Adobe manager. His role in the development of PostScript is discussed by John Warnock here: http://www.epsg.org.uk/pub/warnock/warnock_01.html Thomas Phinney 20:02, 17 August 2006 (UTC)

## PCL6 is not Postscript

Nor is it even close. So I reverted. --Rpresser 05:48, 11 March 2006 (UTC)

## Pipe?

Any one know what the pipe is that is given before a mast, happens and what the pipe is when it is over? Is there any reference to follow?

Some of the items in the "hacks" section link to external pages selling the source code in question. Since there are free examples as well, I can't see much point in having them there.

I'm not removing them yet, in case someone comes up with a good reason to keep them.

Robert 11:32, 14 May 2006 (UTC)

## Too much font stuff?

On the one hand, there's no denying that font handling is a critical part of PostScript, and that the existence of scalable Type 1 fonts was key in the early adoption of the PostScript language. But I am still skeptical that the latest material on CFF, Type 2, and CID-keyed fonts belongs here, any more than similar material on TrueType would belong here - PostScript devices all have native TrueType support, and have done so for well over a decade. This stuff should all be separate and linked, I'd say. Indeed, I think even Type 1 should also be a separate, referenced article rather than part of this article. Thoughts? Thomas Phinney 20:07, 17 August 2006 (UTC)

## No mention of resolution Independence?

--Navstar 22:43, 2 November 2006 (UTC)

## Mac OS X

It was my understanding that Mac OS X has postscript highly integrated into the operating system yet the article doesn't really mention this. Theshibboleth 07:24, 11 December 2006 (UTC)

Nah, Quartz is PDF, not PostScript (well, the common subset, actually). Inspired by Display Postscript, though. EdC 19:22, 11 December 2006 (UTC)

Why is PostScript a multiparadigm PL?? As much as I know it only supports iterative programming. Said: Rursus 14:12, 2 June 2007 (UTC)

Do you mean imperative, I don't see any mention of iterative on that linked page. -John Doe

PostScript supports functional programming style well given that the model is based on combinatory calculus. Please see the language Joy for an example of combinatory model. Blufox (talk) 19:24, 31 December 2007 (UTC)

## ps edit

What tools are available to edit postscript files? To downsample or remove embedded images? -69.87.200.8 23:56, 21 September 2007 (UTC)

## PostScript today?

Is PostScript still relevant? —Preceding unsigned comment added by 72.67.35.214 (talk) 18:33, 16 April 2008 (UTC)

Without a doubt. If I were to estimate, it has support among over a million printers world wide, where available on these printers it is used as the page description language of choice, from soho to enterprise production printers. 124.171.29.232 (talk) 10:01, 24 April 2008 (UTC)

## Use of Homogeneous Coordinates

The article claims that translation (!) and rotation are handled using a "2D Transformation Matrix". I doubt that many implementations will do this. It supposedly is a lot easier and more efficient to use a 3D matrix instead and a technique called homogeneous coordinates. This allows rotations and translations to be combined easily into a single matrix that needs to be kept as current context. Looking at the Ghostscript API suggests that this it at least the way it is handled in Ghostscript. See also http://merganser.math.gvsu.edu/david/psseminar/index.html 84.154.14.147 (talk) 15:40, 12 May 2008 (UTC)

## Not influenced by Forth

Quoting the first edition of the PostScript Language Reference Manual "Design System language and its successors bear a superficial resemblance to the FORTH programming language, their conception and development were entirely independant of FORTH."

However, it is correct to say the PostScript is influenced by Lisp, quoting the PostScript Language Reference Manual again,

"The data model includes elements, such as numbers, strings, and arrays, that are found in many modern programming languages. It also includes the ability to treat programs as data and to monitor and control many aspects of the language's execution state; these notions are derived from programming languages such as LISP." 124.168.170.252 (talk) 04:12, 15 July 2008 (UTC)

## Mention of Units

Previously there was a more accurate description of the unit of length before a lot of the technical detail on postscript was removed from the article.

Given that this material was removed, is the mention of the units of length even relevant?

Also, as cited by the PLRM (the all important and accurate red book):

"Note: The default unit size (1/72 inch) is approximately the same as a "point," a unit widely used in the printing industry. It is not exactly the same as a point, however; there is no universal definition of a point." (Pg 183, Postscript Language Reference Manual, 3/e)

ergo: claiming the unit is typographical points is inaccurate. Akunokuroneko (talk) 04:35, 5 December 2008 (UTC)

## Level terminology

"PostScript 3 (Adobe dropped the "level" terminology in favor of simple versioning) ..."

The Postscript Language Reference still uses it in several places, for example:

"With this third advance of the language, which we call LanguageLevel 3, ..." (Postscript Language Reference, third edition, page xiii)

Are there any references to support this claim? Maybe Adobe uses PostScript 3 merely as a shorthand. 83.135.16.230 (talk) 14:42, 19 December 2008 (UTC)

## Concatenative?

I'm not sure if it's appropriate to describe PostScript as "concatenative" (although technically it is), as it was conceived long before the paradigm was invented (e.g. the language reference doesn't really talk about function composition). Frankly it sounds like an attempt to hijack some respectability for the term (although the edit is made in good faith, no doubt).

At least I'd argue that concatenativity isn't actually a defining characteristic of PostScript (I'd suggest "page description language" or such instead), and it therefore shouldn't be billed as concatenative in the opening paragraph. 77.72.57.237 (talk) 06:59, 24 April 2009 (UTC)

## PostScript interpreter written in Go

I have removed the external link to this again. If it is indeed notable, then it should be mentioned in the main body of the article, and supported by a proper citation of a reliable third-party source. Until then, an external link to the project is entirely inappropriate, especially one originally posted by a somebody with a clear vested interest. Also, the fact that somebody else restored the link doesn't legitimise it unless there is clear evidence that that somebody learnt about it other than from the revision history if the Wikipedia article itself; this would set a very dangerous precedent if allowed. — Preceding unsigned comment added by Acasson (talkcontribs) 12:39, 4 January 2011 (UTC)

Sorry, forgot to sign that. Acasson (talk) 12:42, 4 January 2011 (UTC)
I was the one who put the link back in. I would have thought that anyone who knows a bit about PostScript would concur that it is clearly inherently notable. But I don't know enough about it to write it up in the body of the article. It is true that I learned about it from the revision history, though I fail to see how that is a dangerous precedent. That's exactly why Wikipedia is useful even when one knows a bit about a subject. Thomas Phinney (talk) 18:25, 8 January 2011 (UTC)
Well, for the record I know a lot about PostScript, having been the principal software engineer of a global yellow pages publishing company for the last 12+ years, and either written or been the architect of all of their page creation software. And, in my own time, I've written a large chunk of a PostScript interpreter myself in Perl (though this is now dormant). So I don't doubt that a considerable (and laudable) effort has gone into this new interpreter so far, and before removing the original link I did look through the code present on code.google.com. Unfortunately, there's zero documentation there, and in the time I had available I was not able to gauge the level of functionality already implemented. Also, it's clearly a one-man project (M. le Goff himself), with no other contributors, and therefore appears not even to be notable within the open source software development community. Nor was there any evidence of anyone out there using it. In 18 months time things may well be different, but right now, forget it. There's no such thing as "inherently notable"; it's an oxymoron. So, I'll finish with a question: if I put the Perl code of my own PS interpreter up on code.google.com, with absolutely no supporting documentation, and link to it from Wikipedia, would that be OK? What if you start one of your own tonight, see how far you get, and link it tomorrow? Acasson (talk) 11:45, 9 January 2011 (UTC)

## Use on windows?

I often want to view PS documents in Windows, but the one supposed windows viewer on the internet does not work. Isn't there some simple way to views these documents in windows? the article is written as if Windows computers don't even exist, or that PS is so common that it obviously works on all Windows machine. 24.214.43.163 (talk) 13:24, 17 January 2011 (UTC)

I have removed your over-hasty addition to the Introduction saying that PostScript "is not easily supported on Windows operating systems". Your own personal experience is really not that notable. I use Ghostscript and GSView on Windows without problems. If you can find and cite a reliable 3rd party source that analyses support for PostScript on Windows, by all means write something balanced in the appropriate section of the article (not the second sentence of the Introduction). Acasson (talk) 10:22, 18 January 2011 (UTC)
Thanks. I got Ghostscript with GSView to work. 24.214.43.163 (talk) 14:01, 21 January 2011 (UTC)

## Revolutionary

In computer assisted photocomposition at a large book manufacturer (Kingsport Press), I had to deal (1969-2003) with different write control languages for typesetters like VideoComp 830 and 570 and Linotron 202, and printers like the IBM 6670 and Xerox 3700. I found Postscript revolutionary: a standard typeset/printer language and file format in a field previously noted for incompatible proprietary write control languages and file formats. It was a sea change in the typesetting/printing industry. It cannot be emphasized enough: PostScript (and PDF) replaced chaos with a standard. Naaman Brown (talk) 13:25, 12 August 2011 (UTC)

## possible typo in the Units of Length section

I may just be reading the RPN wrong, but the definition of mm in the idiomatic PS code looks like 360/172, not 172/360 as it should be. thoughts? 64.252.202.213 (talk) 17:17, 29 November 2011 (UTC)

## The sign - above the 7 ?

$\text{1 point} = \frac{1}{72}\text{ inch} = \frac{127}{360}\text{ mm} = 352.\overline 7\text{ micrometer}.$

What does mean the sign - above the last 7  ?

Thanks.

--AXRL (talk) 19:51, 15 February 2012 (UTC)

It signifies a repeating decimal.--Oneiros (talk) 17:43, 22 February 2012 (UTC)

## discussion of graphic model?

I'd like to see some discussion of PostScript's graphic model. For example, the notion of composing an image by adding successive layers. — Preceding unsigned comment added by 64.142.15.200 (talk) 18:16, 26 April 2012 (UTC)

## No mention of PostScript Fax?

174.24.77.231 (talk) 10:31, 13 August 2012 (UTC) Warren Jokinen