feat: add last evaluate result at _ variable in relp

[yazaldefilimone]

I don’t know, but I think this is not a good approach for that. I see that it is not possible to access this property using this._ or globalThis._. I don’t know how to set it global ctx with changes only in the REPL file.

[BobVarioa]

Won't this break after subsequent runs? If we're going with this approach it should be var not let.

[yazaldefilimone]

I don’t understand what you are saying.

are you referring to redeclaring the let statement? In this case, we only declare it once for each sequence (just change a assign expression)

[CanadaHonk]

Can't you just do _ = instead of having to deal with let/var and check every time/etc?

[yazaldefilimone]

hmmm, makes sense i’ve made the change...

[CanadaHonk]

Can't you just do _ = instead of having to deal with let/var and check every time/etc?

[BobVarioa]

I personally don't really like this approach, I feel like this should be done with some AST manipulation in compiler.js that just checks if we're running in a REPL context. Something that essentially checks if the last statement of main is a ExpressionStatement (or something else which can be put in an Expression), and then replacing that last statement with an assignment to _.
If we were to stay with this approach, there needs to be a lot more serialization logic, JSON.stringify is very lossy.

[yazaldefilimone]

I personally don't really like this approach, I feel like this should be done with some AST manipulation in compiler.js that just checks if we're running in a REPL context. Something that essentially checks if the last statement of main is a ExpressionStatement (or something else which can be put in an Expression), and then replacing that last statement with an assignment to _. If we were to stay with this approach, there needs to be a lot more serialization logic, JSON.stringify is very lossy.

ummmmm

In this case:

const age = 19

the last exp in ast became:

_ = const age = 19

[yazaldefilimone]

I personally don't really like this approach, I feel like this should be done with some AST manipulation in compiler.js that just checks if we're running in a REPL context. Something that essentially checks if the last statement of main is a ExpressionStatement (or something else which can be put in an Expression), and then replacing that last statement with an assignment to _. If we were to stay with this approach, there needs to be a lot more serialization logic, JSON.stringify is very lossy.

I think if you want manipulate ast directly you nneed suport vistor pattern... maybe bacoume ast to do that...

I personally don't really like this approach, I feel like this should be done with some AST manipulation in compiler.js that just checks if we're running in a REPL context. Something that essentially checks if the last statement of main is a ExpressionStatement (or something else which can be put in an Expression), and then replacing that last statement with an assignment to _. If we were to stay with this approach, there needs to be a lot more serialization logic, JSON.stringify is very lossy.

ummmmm

In this case:

const age = 19

the last exp in ast became:

_ = const age = 19

I think if you want to manipulate the ast directly, wee need to support the visitor pattern in ast or another algorithm. This ensures proper handling of cases like the last exp is const declarations or other...