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Groups > comp.compilers > #1855
| From | Tom <treid3@centurylink.net> |
|---|---|
| Newsgroups | comp.compilers |
| Subject | Re: Going backwards from a Language(or set of expressions) to a Grammar |
| Date | 2017-04-17 03:19 +0000 |
| Organization | Model Railroaders Unanimous |
| Message-ID | <17-04-016@comp.compilers> (permalink) |
| References | <17-04-014@comp.compilers> |
Seima Rao <seimarao@gmail.com> wrote in news:17-04-014@comp.compilers: > Hi, > > Is it possible generally to arrive at a grammar from > a language or set of expressions ? It depends on the language properties. It can be simple to impossible. Your question implied that you thoroughly know the language and wanted to derive its grammar sufficiently to write a parser/complier to (correctly) process example programs/expressions. An experienced compiler writer will need some time to study what category of grammar is needed. (Regular) expressions just need an lexical analyzer. Many languages like Pascal and Modula2 are LL-1 and the grammars and parsers are straightforward recursive descent. Other languages like C and its bethren need more complex bottom-up parsers and preprocessors for disambiguation. Large context sensitive languages (English for example) have a high error rate. So, your answer is yes for simple with some practice and understanding and can be extrememly had as the language gets complexity. Elegant
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Going backwards from a Language(or set of expressions) to a Grammar Seima Rao <seimarao@gmail.com> - 2017-04-16 19:01 +0530 Re: Going backwards from a Language(or set of expressions) to a Grammar Seima Rao <seimarao@gmail.com> - 2017-04-17 08:31 +0530 Re: Going backwards from a Language(or set of expressions) to a Grammar Tom <treid3@centurylink.net> - 2017-04-17 03:19 +0000 Re: Going backwards from a Language(or set of expressions) to a Grammar Alain Ketterlin <alain@universite-de-strasbourg.fr> - 2017-04-17 12:57 +0200 Re: Going backwards from a Language(or set of expressions) to a Grammar "Derek M. Jones" <derek@_NOSPAM_knosof.co.uk> - 2017-04-17 15:29 +0100 Re: Going backwards from a Language(or set of expressions) to a Grammar Stefan Monnier <monnier@iro.umontreal.ca> - 2017-05-06 22:02 -0400
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