grammar.txt

file                        : statements*
statement                   : ((expr | ret ) ';') | branching | block;
seperate by \n

expr                        : nr_expr               |
                              infix_call            ;

nr_expr                     : '(' expr ')'          |
                              assignment            |
                              block                 |
                              call                  |
                              literal               |
                              identifier            ;

ret                         : 'ret' expr ;

branching                   : branching_if | branching_while;

branching_if                : 'if' '(' expr ')' positive ('else' negative)? ;
positive                    : statement ;
negative                    : statement ;

branching_while             : 'while' '(' expr ')' statement ;

assignment                  : assignment_left '=' assignment_right ;
assignment_left             : identifier    |
                              variable_decl |
                              function_decl ;
assignment_right            : expr;

variable_decl               : 'let' identifier ;

identifier_list             : (identifier ',')* identifier ;
function_decl               : 'let' identifier '(' identifier_list? ')' ;

infix_call                  : infix_call_left identifier infix_call_right ;
infix_call_left             : nr_expr ;
infix_call_right            : expr ;

argument_list               : (expr ',')* expr ;
call                        : identifier '(' argument_list? ')' ;

block                       : '{' (statement | COMMENT)* '}' ;

literal                     : type_float  |
                              type_int    |
                              type_bool   |
                              type_string ;

type_float                  : FLOAT ;
type_int                    : INTEGER ;
type_bool                   : BOOL ;
type_string                 : STRING ;

FLOAT                       : [0-9]+ '.' [0-9]+ ;
INTEGER                     : [0-9]+ ;
STRING                      : '"' [a-zA-Z0-9]* '"' ;
BOOL                        : 'true' | 'false' ;

identifier                  : IDENTIFIER ;
IDENTIFIER                  : Alpha+(Numeric|Alpha)* ;