Method parseSubstrFunc

parse/parse.go:165–211

parses the ${param:offset} string function parses the ${param:offset:length} string function

(name string)

// parses the ${param:offset} string function
// parses the ${param:offset:length} string function
func (t *Tree) parseSubstrFunc(name string) (Node, error) {
	node := new(FuncNode)
	node.Param = name

	t.scanner.accept = acceptOneColon
	t.scanner.mode = scanIdent
	switch t.scanner.scan() {
	case tokenIdent:
		node.Name = t.scanner.string()
	default:
		return nil, ErrBadSubstitution
	}

	// scan arg[1]
	{
		param, err := t.parseParam(rejectColonClose, scanIdent)
		if err != nil {
			return nil, err
		}

		// param.Value = t.scanner.string()
		node.Args = append(node.Args, param)
	}

	// expect delimiter or close
	t.scanner.accept = acceptColon
	t.scanner.mode = scanIdent | scanRbrack
	switch t.scanner.scan() {
	case tokenRbrack:
		return node, nil
	case tokenIdent:
		// no-op
	default:
		return nil, ErrBadSubstitution
	}

	// scan arg[2]
	{
		param, err := t.parseParam(acceptNotClosing, scanIdent)
		if err != nil {
			return nil, err
		}
		node.Args = append(node.Args, param)
	}

	return node, t.consumeRbrack()
}

// parses the ${param%word} string function
// parses the ${param%%word} string function