16th October
Implementing the Pratt parser: Boolean Literals & Grouped Expressions
Boolean
These are not any different from parsing integer literal, so it was fairly straightforward. Being able to parse boolean literals meant the tests for prefix & infix expressions could be now extended to include booleans.
Grouped Literals
Ex: 5 * (2 + 2);
This was also surprisingly easy, thanks to the way the parser is structured. All that
was needed doing was defining a prser when a paranthesis was encountered. All the parser
did was peek forward to the next token and the parseExpression method did the rest. Without the
parenthesis it's just an infix statement. Once you got the statement back, all you had to do
was ensure and peek the closing paren (.
The concept of assosiating token types to functions makes things really easy to extend. I was under the impression that this would be a long section, quite shocked when it was done in a few lines. Quite incredible.