Konzeption Prototyp Rekursion

Rekursion

1. Type-inference (done)

• implemented in infer_types.pl
• detects stupid errors (list used as a number etc.)
• provides information about argument positions

a([],0).
a(N,[A|Rest]):- N is ...

2. Idiom dection and matching (analyse.pl)

• detection of schemata / idioms, comparision:
  construction, deconstruction, same
  accumulation, consumption, consumption1
  see index.plht (need to load analyse.pl first)
• superficial comparision to see if it looks like a sample solution
• provides additional information about argument position
• idiom detector -> list of idiom terms
• filtering of idiom terms -> only keep the interesting ones (same, list_uncons, list_cons, basecase, recursion, accu, successor, predecessor)
• matching of the filtered terms w/ idiom terms from sample solution
  • idea:

...:- match_bags(IdiomsFromUser, IdiomsFromSample,_IdiomMap,zuordnen_idiom,20), ...
zuordnen_idiom(accu(_,_),accu(_,_))-->[].

• result: possible mappings between predicates, argument positions

3a. Testing

• needs information about argument positions
• carefully selected test cases, random testing

3b. Transformation to Normal Form and subgoal matching

last([E],E). => last(L,E):-L=[E|T],T=[].

• identification of missing / superfluous subgoals (auswertung.pl)

4. Instantiation check

• should not be needed in the presence of testing?
• arithmetic (checkInst)
• "monotonicity" of instantiation, e.g. broken construction of a list (look at the sample solution --- monotonicity constrainst fulfilled in the sample solution should be enforced in the user solution)

5. Syntax check with limited grammar

6. Open issues