func nextToken()

in query/parse.go [396:474]

• 71 lines of code
• 17 McCabe index (conditional complexity)

func nextToken(in []byte) (*token, error) {
	left := in[:]
	parenCount := 0
	var cur token
	if len(left) == 0 {
		return nil, nil
	}

	if left[0] == '-' {
		return &token{
			Type:  tokNegate,
			Text:  []byte{'-'},
			Input: in[:1],
		}, nil
	}

	foundSpace := false

loop:
	for len(left) > 0 {
		c := left[0]
		switch c {
		case '(':
			parenCount++
			cur.Text = append(cur.Text, c)
			left = left[1:]
		case ')':
			if parenCount == 0 {
				if len(cur.Text) == 0 {
					cur.Text = []byte{')'}
					left = left[1:]
				}
				break loop
			}

			cur.Text = append(cur.Text, c)
			left = left[1:]
			parenCount--

		case '"':
			t, n, err := parseStringLiteral(left)
			if err != nil {
				return nil, err
			}
			cur.Text = append(cur.Text, t...)
			left = left[n:]
		case '\\':
			left = left[1:]
			if len(left) == 0 {
				return nil, fmt.Errorf("query: lone \\ at end")
			}
			c := left[0]
			cur.Text = append(cur.Text, '\\', c)
			left = left[1:]

		case ' ', '\n', '\t':
			if parenCount > 0 {
				foundSpace = true
			}
			break loop
		default:
			cur.Text = append(cur.Text, c)
			left = left[1:]
		}
	}

	if len(cur.Text) == 0 {
		return nil, nil
	}

	if foundSpace && cur.Text[0] == '(' {
		cur.Text = cur.Text[:1]
		cur.Input = in[:1]
	} else {
		cur.Input = in[:len(in)-len(left)]
	}
	cur.setType()
	return &cur, nil
}