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consult/1

Description​

consult/1 is a predicate which read files as Prolog source code.

Signature​

consult(+Files) is det

where:

  • Files represents the source files to be loaded. It can be an atom or a list of atoms representing the source files.

The Files argument are typically URIs that point to the sources file to be loaded through the Virtual File System (VFS). Please refer to the open/4 predicate for more information about the VFS.

Examples​

Consult a Prolog program from the embedded library​

This scenario demonstrates how to load a library file and use one of its predicates.

Here are the steps of the scenario:

  • Given the query:
consult('/v1/lib/lists.pl'),
member(Who, [alice,bob]).
  • When the query is run (limited to 1 solutions)
  • Then the answer we get is:
height: 42
gas_used: 4013
answer:
  has_more: true
  variables: ["Who"]
  results:
  - substitutions:
    - variable: Who
      expression: "alice"

Consult several Prolog programs at once​

This scenario demonstrates consult/1 with a list of files.

Here are the steps of the scenario:

  • Given the program:
:- consult([
  '/v1/lib/bank.pl',
  '/v1/lib/chain.pl'
]).
  • Given the query:
current_predicate(bank_balances/2),
current_predicate(header_info/1).
  • When the query is run (limited to 2 solutions)
  • Then the answer we get is:
height: 42
gas_used: 4792
answer:
  has_more: false
  variables:
  results:
  - substitutions: