strange if-else parser using Flex & Bison

This is a simple parser which can parse expressions in a strange way. The syntax for this language is very similar to if-else of C++. Inside curly braces or round braces, you can enter numbers or similar expressions and it will evaluate the final result.

Tokens used

digit       [0-9]+
if          "if"
else        "else"
cleft       "{"
cright      "}"
rleft       "("
rright      ")"

Grammar used

• rL = round left = (
• cL = curly left = {

  prog:
   prog atom
  |    prog SEMICOLON
  |
  atom:
   IF rL atom rR cL atom cR ELSE cL atom cR
  |    IF rL atom rR cL atom cR
  |    DIGIT

Sample inputs

if(1){33}
else{55};

if(1){
    if(1){33}
    else{55}
}
else{
    if(1){33}
    else{55}
};

How to run?

• make
• Enter inputs as mentioned above.