예제 #1
0
파일: builtin.go 프로젝트: vzaramel/golog
// findall/3
func BuiltinFindall3(m Machine, args []term.Term) ForeignReturn {
	template := args[0]
	goal := args[1]

	// call(Goal), X=Template
	x := term.NewVar("_")
	call := term.NewCallable("call", goal)
	unify := term.NewCallable("=", x, template)
	prove := term.NewCallable(",", call, unify)
	proofs := m.ClearConjs().ClearDisjs().ProveAll(prove)

	// build a list from the results
	instances := make([]term.Term, 0)
	for _, proof := range proofs {
		t, err := proof.Resolve(x)
		MaybePanic(err)
		instances = append(instances, t)
	}

	return ForeignUnify(args[2], term.NewTermList(instances))
}
예제 #2
0
파일: read.go 프로젝트: vzaramel/golog
// parse a single term
func (r *TermReader) term(p priority, i *lex.List, o **lex.List, t *term.Term) bool {
	var op, f string
	var t0, t1 term.Term
	var opP, argP priority
	//  fmt.Printf("seeking term with %s\n", i.Value.Content)

	// prefix operator
	if r.prefix(&op, &opP, &argP, i, o) && opP <= p && r.term(argP, *o, o, &t0) {
		opT := term.NewCallable(op, t0)
		return r.restTerm(opP, p, *o, o, opT, t)
	}

	// list notation for compound terms §6.3.5
	if r.tok('[', i, o) && r.term(999, *o, o, &t0) && r.listItems(*o, o, &t1) {
		list := term.NewCallable(".", t0, t1)
		return r.restTerm(0, p, *o, o, list, t)
	}
	if r.tok('[', i, o) && r.tok(']', *o, o) {
		list := term.NewAtom("[]")
		return r.restTerm(0, p, *o, o, list, t)
	}

	// parenthesized terms
	if r.tok('(', i, o) && r.term(1200, *o, o, &t0) && r.tok(')', *o, o) {
		//      fmt.Printf("open paren %s close paren\n", t0)
		return r.restTerm(0, p, *o, o, t0, t)
	}

	switch i.Value.Type {
	case lex.Int: // integer term §6.3.1.1
		n := term.NewInt(i.Value.Content)
		*o = i.Next()
		return r.restTerm(0, p, *o, o, n, t)
	case lex.Float: // float term §6.3.1.1
		f := term.NewFloat(i.Value.Content)
		*o = i.Next()
		return r.restTerm(0, p, *o, o, f, t)
	case lex.Atom: // atom term §6.3.1.3
		a := term.NewAtomFromLexeme(i.Value.Content)
		*o = i.Next()
		return r.restTerm(0, p, *o, o, a, t)
	case lex.String: // double quated string §6.3.7
		cl := term.NewCodeListFromDoubleQuotedString(i.Value.Content)
		*o = i.Next()
		return r.restTerm(0, p, *o, o, cl, t)
	case lex.Variable: // variable term §6.3.2
		v := term.NewVar(i.Value.Content)
		*o = i.Next()
		return r.restTerm(0, p, *o, o, v, t)
	case lex.Void: // variable term §6.3.2
		v := term.NewVar("_")
		*o = i.Next()
		return r.restTerm(0, p, *o, o, v, t)
	case lex.Comment:
		*o = i.Next()              // skip the comment
		return r.term(p, *o, o, t) // ... and try again
	}

	// compound term - functional notation §6.3.3
	if r.functor(i, o, &f) && r.tok('(', *o, o) {
		var args []term.Term
		var arg term.Term
		for r.term(999, *o, o, &arg) { // 999 priority per §6.3.3.1
			args = append(args, arg)
			if r.tok(')', *o, o) {
				break
			}
			if r.tok(',', *o, o) {
				continue
			}
			panic("Unexpected content inside compound term arguments")
		}
		f := term.NewTermFromLexeme(f, args...)
		return r.restTerm(0, p, *o, o, f, t)
	}

	*t = term.NewError("Syntax error", i.Value)
	return false
}