grammer.txt

P.S work in progress 


GRAMMER RULES FOR GRAMMER (G)
-----------------------------

<program> -> <block>
<block> -> <statements> 
<statements> -> <statements> <statement> | e 
<statement> -> <ifstatement> | <ifstatement><elsestatement> |<forstatement> | <functionstatement> | 
               <declarestatement> | <returnstatement> | <initstatement> | 
               <assignstatement> | '{'<statements> '}'
<ifstatement> -> 'if' <expression> <statement> 
<elsestatement> -> 'else' <statement> 
<forstatement> -> 'for' <identifier> 'in' <expression> <statement>
<functionstatement> -> 'define' <identifier> '(' <argslist> ')' <statement>
<declarestatement> -> 'declare' <identifier_list> <newline>
<returnstatement> -> 'return' <expression> <newline>
<assignstatement> -> <identifier><assign><expression><newline> | 
                     <identifier>'[' <index_access> ']' <assign> <expression><newline>  
<initstatement> -> 'init' <assignstatement>
<expression> -> '(' <expression> ')' | <arithmetic_expression> | <relational_expression> |
                 <function_expression> | <index_expression> | <range_expression> |
                 <function_callexpression>
                 
<function_callsexpression> -> <identifier> '(' <argslist> ')' <newline>
<argslist> -> <argslist> ',' <param> | <param> | e  
<identifier_list> -> <identifier_list> ',' <identifier> | <identifier> | e 
<identifier> -> <letter> | <letter> <number> 
<arithmetic_expression> -> <expression> '+' <term> | <expression> '-' <term> 
<term> -> <term> * <factor> | <term> / <factor> | <factor>
<factor> -> <number> | '(' <expression> ')'
<newline> -> '\n' | e
<string_literal> -> '\''<alpha>'\'' | '"'<alpha>'"' | "" | ''
<letter> -> '_' |'a' | 'b' | 'c' | 'd' | 'e' | 'f' | 'g' | 'h' | 'i' | 'j' | 'k' |
            'l' | 'm' | 'n' | 'o' | 'p' | 'q' | 'r' | 's' | 't' | 'u' | 'v' |
            'w' | 'x' | 'y' | 'z'
<number> -> <digit> <number> | e
<digit> -> 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
<range_expression> -> '(' <number> '..' <number> ')'

// UNDONE - PR
<relational_expression>
<function_expression>
<index_expression>
<function_callexpression>
<alpha>

SAMPLE STRINGS FROM TARGET GRAMMER (G)
--------------------------------------


for i in (1..10) {
     for j in (5..9) {
	print i , j 	
    }
}

define subtext(){
    return "ehl"
}

define entry(){
    
    declare text
    text = 6

    init subval = 89
    print subval, text

    // while expression 
    while i < j {
	     print i++
    }
}

define main(args){
   for arg in args {
	   print arg
  }

}

--------------------------------------
//
  module stdlib
  package main
//