READ ME COMPILER EBNF

This code is a little project made for a compilation course

1°) Write an EBNF file

identifier
"terminal"
[] for optionnal rule
{} multiple rule (0..*)
() groupement
, concatenation
| alternative
; end of rule

How to make a rule

example:

	IfStatement = ("if",{Statement},["else",{Statement}],"end");

If you call a rule (here Statement) you should make sure it exist, unless the call is about identifier and number

If you want to make a rule about identifier and number , write it likewise (as a call not a rule by itself) on your ebnf file then when the output file is made , make sure to add: (expect :identifier).value in the parseIdentifier function (expect :digit).value in the parseNumber function

You shouldn't write anything more or make sure to return the value of the token.

There is no priority symbol between "|" and "," so you should write groupement if needed
If you write a rule which call itself, there should be alternative statement and you should write each statement in groupement

example :
```
Expression = (Identifier) |( Expression , "," , Expression);
```
You must not write a rule such as :
```
Expression = (Expression, "," , Expression )
```
or
```
Statement = Statement
```
as the output programme will end up in a infinite loop

If your Statement have the rule calling itself first (in the | statement ) It should be write at the end of the alternative statements example:

	Expression = (Identifier) | ( "(" , Expression , ")" ) | ( Expression , "," , Expression);

Complete the EBNF file

Normally the lexer will recognize any symbol (meaning there will be no reporting of error with the lexer), with you want to change it delete in TOKEN_DEF in parser_etudiant.rb the "autre" regexp ( /./) and write the symbol needed as a regexp:

example:

	:pound	=> /\£/,

2°) Run the compiler

On the termimal write 'ruby compiler.rb filename'

The output files will be on the folder 'output':

            - output_codewriting.rb : the parser
            - output_astwriting.rb : the ast class
            - output_html.html : the ebnf rewritten with colour
            - output_rewrite.txt : the ebnf rewritten

3°) Efficiency of the compiler

For analyse purposes it have been added in file a counter to record the position of the token in the stream. The file data_stream.data is write by the first parser and by the output parser (in their respective folder). Then you can use the MATLAB script to easily plot the data

Elessog/Compil

READ ME COMPILER EBNF

1°) Write an EBNF file

2°) Run the compiler

3°) Efficiency of the compiler