Function godeep

dql/parser.go:3104–3494

godeep constructs the subgraph from the lexed items and a GraphQuery node.

(it *lex.ItemIterator, gq *GraphQuery)

// godeep constructs the subgraph from the lexed items and a GraphQuery node.
func godeep(it *lex.ItemIterator, gq *GraphQuery) error {
	if gq == nil {
		return it.Errorf("Bad nesting of predicates or functions")
	}
	var count countType
	var alias, varName string
	curp := gq // Used to track current node, for nesting.
	for it.Next() {
		item := it.Item()
		switch item.Typ {
		case lex.ItemEOF:
			return nil
		case itemRightCurl:
			return nil
		case itemPeriod:
			// looking for ...
			dots := 1
			for range 2 {
				if it.Next() && it.Item().Typ == itemPeriod {
					dots++
				}
			}
			if dots == 3 {
				it.Next()
				item = it.Item()
				if item.Typ == itemName {
					// item.Val is expected to start with "..." and to have len >3.
					gq.Children = append(gq.Children, &GraphQuery{fragment: item.Val})
					// Unlike itemName, there is no nesting, so do not change "curp".
				}
			} else {
				return item.Errorf("Expected 3 periods (\"...\"), got %d.", dots)
			}
		case itemName:
			peekIt, err := it.Peek(1)
			if err != nil {
				return item.Errorf("Invalid query")
			}
			if peekIt[0].Typ == itemName && strings.ToLower(peekIt[0].Val) == "as" {
				varName = item.Val
				it.Next() // "As" was checked before.
				continue
			}

			val := collectName(it, item.Val)
			valLower := strings.ToLower(val)

			peekIt, err = it.Peek(1)
			if err != nil {
				return err
			}
			if peekIt[0].Typ == itemColon {
				if len(alias) > 0 {
					return item.Errorf("Invalid colon after alias declaration")
				}
				alias = val
				it.Next() // Consume the itemcolon
				continue