Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.compilers > #837
| From | "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> |
|---|---|
| Newsgroups | comp.compilers |
| Subject | Re: Compiling expressions |
| Date | 2013-01-04 10:18 +0100 |
| Organization | cbb software GmbH |
| Message-ID | <13-01-014@comp.compilers> (permalink) |
| References | <12-12-035@comp.compilers> <12-12-038@comp.compilers> <13-01-012@comp.compilers> |
On Thu, 3 Jan 2013 12:01:33 -0800 (PST), James Harris wrote: >> I extended the method, which fairly old, towards non-associativity (#6), >> advanced parenthesis (#5, keyed parameter associations), and split >> association priorities into left-right pairs. But basically it is still the >> same twin-stack method. Everything is table-driven, of course. > > Is it based on a Pratt parser? I see your comment and saw left and > right priorities mentioned. I have never spent the time to understand > Pratt parsers or why they need both. To deal with left- and right- > associativity if I ever need to I was thinking to use the lowest bit > of the precedence - something along the lines of clearing the bit on > one side before a comparison. Then each operator would only need a > single precedence. Priority + direction sufficiently less general. For example it fails to capture asymmetrically associated operations, e.g. assignment. Provided you wanted assignment as an operator, you would like to have it rather this way: a + b := c + d --> a + (b := (c + d)) Priority + direction model cannot handle this. Here the left priority of := must be sufficiently higher than the right one. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de
Back to comp.compilers | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Compiling expressions James Harris <james.harris.1@gmail.com> - 2012-12-29 05:11 -0800
Re: Compiling expressions glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-29 23:33 +0000
Re: Compiling expressions James Harris <james.harris.1@gmail.com> - 2013-01-02 09:04 -0800
Re: Compiling expressions "matzebraun@googlemail.com" <matzebraun@googlemail.com> - 2013-01-03 07:13 -0800
Re: Compiling expressions Horst von Brand <vonbrand@inf.utfsm.cl> - 2013-01-14 16:31 -0300
Re: Compiling expressions "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2012-12-30 08:58 +0100
Re: Compiling expressions James Harris <james.harris.1@gmail.com> - 2013-01-02 09:10 -0800
Re: Compiling expressions James Harris <james.harris.1@gmail.com> - 2013-01-03 12:01 -0800
Re: Compiling expressions "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> - 2013-01-04 10:18 +0100
Re: Compiling expressions torbenm@diku.dk (Torben Ægidius Mogensen) - 2013-01-03 16:49 +0100
Re: Compiling expressions James Harris <james.harris.1@gmail.com> - 2013-01-03 13:33 -0800
Re: Compiling expressions James Harris <james.harris.1@gmail.com> - 2013-01-06 00:57 -0800
Re: Compiling expressions "James Harris \(es\)" <james.harris.1@gmail.com> - 2013-03-07 11:11 +0000
csiph-web