Class: SWIPL::Predicate

Inherits:
Object
  • Object
show all
Defined in:
lib/swipl/predicate.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(id, arity) ⇒ Predicate

Returns a new instance of Predicate.



4
5
6
7
 
# File 'lib/swipl/predicate.rb', line 4

def initialize( id, arity )
  @pred_id = id
  @arity = arity
end

Class Method Details

.find(name, arity) ⇒ Object 



9
10
11
12
13
 
# File 'lib/swipl/predicate.rb', line 9

def self.find( name, arity )
  name_ptr = FFI::MemoryPointer.from_string( name.to_s )
  id = CFFI.PL_predicate( name_ptr, arity, nil )
  Predicate.new( id, arity )
end

Instance Method Details

#query_normally(frame) ⇒ Object

Parameters:

  • frame —

    the frame to allocate the parameters



16
17
18
19
20
 
# File 'lib/swipl/predicate.rb', line 16

def query_normally( frame )
  params = frame.refs( @arity )
  query_id = CFFI.PL_open_query( nil, PL_Q_NORMAL, @pred_id, params[0].id )
  Query.new( query_id, params )
end

#query_normally_with(frame, inputs) ⇒ Object 



22
23
24
25
26
27
28
29
30
31
32
33
34
35
 
# File 'lib/swipl/predicate.rb', line 22

def query_normally_with( frame, inputs )
  raise "insufficent parameters for arity" if inputs.length != @arity

  params = frame.refs( @arity )
  (0..(@arity-1)).each do |index|
    source = inputs[ index ]
    if source
      params[index].unify_with( inputs[index] )
    end
  end

  query_id = CFFI.PL_open_query( nil, PL_Q_NORMAL, @pred_id, params[0].id )
  Query.new( query_id, params )
end