Subprogram Memoizer - Githubissues

In order to avoid re-evaluating programs and sub-programs multiple times we want to save the results of their evaluations so that if the interpreter is called again time it only needs to recall the results rather that recalculate.

For instance if program candidate P is provided to the interpreter

(Plus
  (Schema "i1")
  (Schema "i2"))

the first time the interpreter will may evaluate it, but the second time, even if that time P is only a sub-program of another program P' it may re-use the memorized (cached) values.

For instance if program candidate P' is

(Times
  (Plus
    (Schema "i1")
    (Schema "i2"))
  (Schema "i3"))

then P is a sub-program of P' and shouldn't be re-evaluated.

In order to store the results of these evaluations I suggest to use the same mechanism for efficiently storing feature values described in issue #16 . That is upon encountering an atom to evaluate, the first thing the interpreter would do is to check whether some values are attached to key

Node "*-AS-MOSES:SchemaValuesKey-*"

if so, then return these values, otherwise proceed with the calculation.

So note that in order to work well the return C++ type of that atomese interpreter should be ProtoAtomPtr, not Handle, just like in Instantiator::execute().

So it goes with saying that in such a case the Atomese interpreter will simply return a proto atom representing the list of values, not the representation described in the Section Update the Atomese Interpreter to Handle Problem Data of issue #3 , but at this point of the development it's fine.

opencog / asmoses

Subprogram Memoizer #17