19th October
Implementing the Pratt parser: Function literals
Function literals look like this:
fn(x, y) {
return x + y;
}The abstract structure of a function looks like this:
fn <parameter> <block statement>Having this structure is a good starting point from defining the type to parsing function literals.
Although, params are new they are just identifiers seperated by command and surrounded by a parantheses. They can also be empty.
There are couple of things to note, functions can return a function inside the body.
fn() {
return fn(x, y) { return x > y; };
}Also, using a function literal as an argument when calling another function is also possible:
myFunc(x, y, fn(x, y) { return x > y; });These seemed a bit daunting when I saw them first and expected parsing function literals
to be a lot more complicated that parsing if-else expressions. Turned out not to be
the case as once parsing function literals as expressions and provide a parsing method
to parse them, the rest just works. In all honesty it felt amazing.
This one was a lot of fun.