Class NotScan

src/runtime/join.ts:470–529

//---------------------------------------------------------------------

export class NotScan {
  id: string;
  strata: BlockStratum[];
  vars: Variable[];
  args: Variable[];
  internalVars: Variable[];
  resolved: any[];

  constructor(id: string, args: Variable[], strata: BlockStratum[]) {
    this.id = id;
    this.strata = strata;
    this.resolved = [];
    let blockVars = [];
    scansToVars(strata, blockVars);
    this.vars = args;
    this.args = args;
    this.internalVars = blockVars;
  }

  resolve(prefix) {
    return resolve(this.args, prefix, this.resolved);
  }

  propose() { return; }
  resolveProposal() { throw new Error("Resolving a not proposal"); }

  accept(multiIndex: MultiIndex, prefix, solvingFor, force?, prejoin?) {
    // if we're in the prejoin phase and this not has no args, then we need
    // to evaluate the not to see if we should run. If we didn't do this, arg-less
    // nots won't get evaluated during Generic Join since we're never solving for a
    // variable that this scan cares about.
    if((!prejoin || this.args.length)
       // if we aren't forcing and not solving for the current variable, then we just accept
       // as it is
       && (!force && !this.internalVars[solvingFor.id] && this.internalVars.length)
       // we also blind accept if we have args that haven't been filled in yet, as we don't
       // have the dependencies necessary to make a decision
       || !fullyResolved(this.args, prefix)) return true;
    let resolved = this.resolve(prefix);
    let notPrefix = [];
    let ix = 0;
    for(let arg of this.args) {
      notPrefix[arg.id] = resolved[ix];
      ix++;
    }
    // console.log("checking not", notPrefix, this.internalVars);
    let results = [notPrefix];
    if(this.strata.length === 1) {
      results = this.strata[0].execute(multiIndex, results, {single: true});
    } else {
      for(let stratum of this.strata) {
        results = stratum.execute(multiIndex, results);
        if(results.length === 0) break;
      }
    }
    // console.log("checked not!", results.length);
    return !results.length;
  }