[CEqEA] MIG grammars

[Rene V. <ve...@ja...>]

Hi,

I've made BNF-style grammars of the MIG specification language available 
as .html-files at https://sourceforge.net/projects/ceqea/files/

They can also be found at
- ftp://ftp.jaist.ac.jp/pub/sourceforge/c/project/ce/ceqea/symbols.html
- ftp://ftp.jaist.ac.jp/pub/sourceforge/c/project/ce/ceqea/syntax.html
- ftp://ftp.jaist.ac.jp/pub/sourceforge/c/project/ce/ceqea/modalities.html

The first of these defines how characters are combined into tokens, 
i.e., the words of the language. The second file defines the main 
syntax, based on the tokens in the first file; this amounts to the 
sentences of the language. The third file defines the modality-specific 
syntax, which is glossed over in the second file in order to separate 
concerns. The second file defines where modality-specific tokens may 
appear in the main syntax, while the third files defines exactly how 
modalities may be written.

The grammars are written as BNFs enriched with regulation-expression 
operators. For example

RuleName
   : option1*
   | (option2a | option2b)+
   | option3a? option3b
   ;

defines RuleName to be
- either 0, 1, or more occurrences of option1-syntax (defined elsewhere)
- or 1 or more occurrences of option2a and/or option2b
- or 0 or 1 occurrences of option3a followed by an option3b.


Please let me know whether this way of presenting the language is 
helpful. The presentation is precise and is intended for reference 
purposes, rather than for learning the language from scratch.

Cheers,
Rene