Re: Lark - A surface syntax for Common Lisp
"Greg Menke (as gregm32768 at comcast dot net)" <[email protected]>
| Newsgroups | gmane.lisp.lispworks.general |
|---|---|
| Message-ID | <[email protected]> |
But how can an editor handle substantial levels of nesting cleanly? It is ever so easy to add/delete a space even by accident and then things get ambiguous. Granted a paren can be added/deleted in a similarly complex lisp tree but all the non-effected structures of the tree are still fully determined. Much of the trouble I have relates to bounding the clauses of conditionals- the only thing separating else condition from the subsequent code is the indent- that is so easily changed even accidentally and there is nothing but the spacing to indicate the programmer's intent. With lisp etc the conditional's final delimiter entirely concludes it without regard to indenting etc. I've written a bunch of python over the years and always run into indenting issues when code gets complex enough. On 2/16/2026 6:29 AM, Jens Axel Søgaard (as jensaxel at soegaard dot net) wrote: > > So, when whitespace is significant, how do you tell whether or not a > space has been added or dropped? Probably more difficult when they get > dropped. > > Do you have to re-analyze the entire function to discern the proper > level of nesting? > > It is more or less the same effort compared to forgetting a right > parenthesis in Lisp. > The automatic indenter will in both languages indent the following > lines incorrectly. > This alerts you that something is wrong - then you look for the problem. > > I can recommend this talk by Matthew Flatt. > > https://www.youtube.com/watch?v=hkiy1rmKA48 > > He brings the syntax into perspective and explains why the choice > makes it possible > to write macros using the lessons learned from Lisp/Scheme/Racket. > > > Den man. 16. feb. 2026 kl. 00.27 skrev David McClain > <[email protected]>: > > So, when whitespace is significant, how do you tell whether or not > a space has been added or dropped? Probably more difficult when > they get dropped. Do you have to re-analyze the entire function to > discern the proper level of nesting? > > >> On Feb 15, 2026, at 15:49, David McClain (as dbm at >> refined-audiometrics dot com) <[email protected]> wrote: >> >> as an aside, >> >> I’m probably too old to appreciate languages that use whitespace >> as a signifier for syntax. >> >> Reminds me too much of the days when I would drop an entire tray >> full of punched cards and had to reassemble the program by hand >> without having had the foresight to punch sequence numbers in the >> final columns. >> >> But I do note that Python and Haskell both seem to use whitespace >> as something of significance. And now Rhombus. >> >> Have you never lost your indentation due to text editors >> compressing runs of spaces into tab characters? Or was that just >> the early days of Emacs? >> >>> On Feb 15, 2026, at 15:39, Jens Axel Søgaard (as jensaxel at >>> soegaard dot net) <[email protected]> wrote: >>> >>> > On a more serious note, the existing S-expr surface syntax is >>> a huge reason for the enormous utility of Lisp macros. Noisy >>> syntaxae (sp?) just make that so much more difficult. >>> >>> FWIW Rhombus is an attempt to apply the lessons learned with >>> S-expression macros for languages with a more familiar syntax. >>> >>> https://docs.racket-lang.org/rhombus-guide/Notation.html >>> >>> /Jens Axel >>> >>> >>> Den søn. 15. feb. 2026 kl. 16.49 skrev David McClain (as dbm at >>> refined-audiometrics dot com) <[email protected]>: >>> >>> On a more serious note, the existing S-expr surface syntax >>> is a huge reason for the enormous utility of Lisp macros. >>> Noisy syntaxae (sp?) just make that so much more difficult. >>> >>> You have issues of syntax operator precedence, left/right >>> binding, etc. Just an absolute mess, and guaranteed to be >>> different in some respects from other popular “noisy” >>> languages. I fully suspect that this is the reason for >>> abandoning early M-syntax for Lisp. >>> >>> After all the effort, S-exprs are simply easier to use and >>> syntax-extend. >>> >>> A simple example of the “noise” level is to just compare >>> JSON with S-expr. You can do absolutely everything with >>> S-exprs that JSON syntax requires, and with half the number >>> of keyboard keystrokes. >>> >>> >>> >>> > On Feb 15, 2026, at 08:14, Greg Menke (as gregm32768 at >>> comcast dot net) <[email protected]> wrote: >>> > >>> > >>> > I used a similar method writing a 8052 embedded cpu >>> assember- a small language built on top of lisp so all the >>> macros etc can be applied, and the effect of "running" it is >>> to emit a located binary ready to run on the cpu. Not used >>> for realsies alas but disassembly of the object code shows >>> it working.. the 8052 being sufficiently simple that its >>> easy to work that out. The theory was complex functions >>> more advanced than simple macro assembly could be built up >>> conveniently using lisp, perhaps not unlike Forth. >>> > >>> > It was fairly simple to write, but did need a bit of >>> nuance to get things to work right eg macros etc. >>> > >>> > Greg >>> > >>> > >>> > On 2/15/2026 8:16 AM, Yuri Davidovsky (as work at >>> disclosure dot ie) wrote: >>> >>> On 15 Feb 2026, at 11:03, Gerry Weaver >>> <[email protected]> wrote: >>> >>> >>> >>> It was actually inspired by several languages. Lark >>> isn't a standalone >>> >>> language that happens to compile to Lisp — it's a skin >>> over Common Lisp. >>> >>> Every Lark construct maps directly to a CL form. fn is >>> defun, struct is >>> >>> defstruct, |x| x * 2 is (lambda (x) (* x 2)), @(...) >>> drops straight into >>> >>> s-expressions. You can call any CL function, use CFFI, >>> define CLOS >>> >>> methods with typed dispatch, write macros with backquote >>> templates. The >>> >>> FFI, the package system, the condition system, the type >>> declarations — >>> >>> it's all CL exposed through a friendly syntax. >>> >> It appears that you picked up where John McCarthy left off. >>> >> >>> >> An interesting approach of making lisp a language that is >>> more suitable for one personally, that is something that I >>> would totally approve as I myself constantly invent ways of >>> doing things differently and more conveniently. I have also >>> been thinking recently about streamlined ways of parsing DSL >>> languages in Lisp (essentially what you are doing here), and >>> I think I haven’t come to a good conclusion how it should work. >>> >> >>> >> Tokenising appears to be easy enough to do using the >>> standard Lisp reader, however I haven’t decided on a good >>> way to do parsing/syntax checking of the resulting list of >>> tokens. How do you go about parsing the tokens in order to >>> extract the syntax patterns (say for an fn definition) and >>> compile them into lisp? Have you used the parsergen package >>> in Lispworks for that, or did you come up with your own >>> parsing tool? >>> >> >>> >> I am not deeply familiar with the topic of computer >>> languages’ parsing and would be interested to hear the >>> perspective of someone who did some work in the area, as you >>> evidently have. >>> >> >>> >> >>> >> >>> >> >>> >> _______________________________________________ >>> >> Lisp Hug - the mailing list for LispWorks users >>> >> [email protected] >>> >> http://www.lispworks.com/support/lisp-hug.html >>> > >>> > _______________________________________________ >>> > Lisp Hug - the mailing list for LispWorks users >>> > [email protected] >>> > http://www.lispworks.com/support/lisp-hug.html >>> >>> >>> _______________________________________________ >>> Lisp Hug - the mailing list for LispWorks users >>> [email protected] >>> http://www.lispworks.com/support/lisp-hug.html >>> >>> >>> >>> -- >>> -- >>> Jens Axel Søgaard >>> >> > > > > -- > -- > Jens Axel Søgaard >