damp.ekeko.logic documentation

Auxiliary logic goals, most of which are currently non-relational.

contains|iteratorbased

(contains|iteratorbased ?c ?e)
Same as contains|memberbased/2, but uses iterators to obtain the elements of c.
It is therefore not implemented in terms of membero/2.
Source

contains|memberbased

(contains|memberbased ?c ?e)
Relation between a collection (seq c) and one of its elements e.
Source

equals

macro

(equals lvar exp)
Non-relational. Projects all logic variables on the right-hand side
that start with a question mark (e.g., ?x), evaluates the resulting
Clojure expression and unifies the result with the left hand-side.
Source

equals-without-exception

macro

(equals-without-exception lvar exp)
Like equals/2, but catches Exception thrown by exp.
Fails if an exception is thrown.
Source

fails

macro

(fails goal)
Succeeds if argument fails. Implements negation as failure.
Source

findall

macro

(findall var goal solutionseq)
Crude approximation of Prolog's findall.
To be improved.

Introduces the first argument as a fresh var
into the lexical scope of the second one. 

Unifies third argment with a clojure vector 
of bindings for the first argument (expected to be a var) 
found in all solutions to the second argument (expected to be a goal).

Examples:
- vector of members within each type declaration:
(ekeko*
  [?t ?members] 
  (ast :TypeDeclaration ?t)
  (findall ?name
           (child :bodyDeclarations ?t ?name)
           ?members))

 - empty vector for each type declaration:
 (ekeko*
   [?t ?nosolutions] 
   (ast :TypeDeclaration ?t)
   (findall ?x
            (all (== 1 2) (== 2 3))
            ?nosolutions))
Source

one

(one g)
If g succeeds, succeeds once.
Source

perform

macro

(perform exp)
Non-relational. Projects all logic variables on the right-hand side
that start with a question mark (e.g., ?x) and evaluates the resulting
Clojure expression.

See also: 
equals/2 if the value of the expression is needed.
suceeds/2 if the expressions should evaluate to true.
Source

same-elements

(same-elements ?col1 ?col2)
Non-relational. Checks whether the two _fully ground_ collections contain the same elements (set equality).
Source

succeeds

macro

(succeeds exp)
Non-relational. Projects all logic variables on the right-hand side
that start with a question mark (e.g., ?x) and verifies that 
the resulting Clojure expression evaluates to true.
Source

succeeds-without-exception

macro

(succeeds-without-exception exp)
Like succeeds/2, but catches Exception thrown by exp.
Fails if an exception is thrown.
Source

v+

macro

(v+ v)
Non-relational. Verifies that logic variable v is ground.
Source

v-

macro

(v- v)
Non-relational. Verifies that logic variable v is not ground.
Source