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by liamilan 1025 days ago
Crumb is garbage collected (there is no need to manually allocated/deallocate memory)... though there is no background "garbage collector" process running... The interpreter for Crumb is a tree-walk interpreter, and it just frees memory whenever it can... Crumb frees memory in the following cases:

1) When a function is finished, all memory related to the scope of that runtime is freed.

2) When an value is not returned out of a statement, or assigned to a variable, said value is freed.

3) When a function is applied, if an argument has no reference (it is not stored in a variable), it is freed.

4) Additionally, if the function itself has no reference (such as in the case of an immediately invoked function), it is freed.

Hope that clarifies things a bit :D

1 comments

Sorry if I got the syntax wrong, but in something like

  f = {
     x = (list 1 2 3)
     y = (list x x)
     z = (get x 1)
     <- y
  }
How does the compiler decides if it must free the memory used by x?
All lists are passed by value and X isn't the return value, would be my guess
It's an interpreter rather than a compiler, and looking at the code it seems to use ref counting
Ref counting makes a lot of sense with the description of the OP, and if there are no cycles it's good.
It should. Everything is copied and by-value, there are no references/pointers or even closures, cycles are impossible. Think Pascal that has garbage collection for strings and dynamic arrays.