# SRFI 10: #, external form

by Oleg Kiselyov

status: final (2000/1/13)

## Abstract

The present SRFI proposes an extensible external representation of Scheme values, a notational convention for future SRFIs. This SRFI adds #,( as a new token and extends production rules of the grammar for a Scheme reader. The #,() form can be used for example to denote values that do not have a convenient printed representation, as well for conditional code compilation. It is proposed that future SRFIs that contain new read syntax for values use the #,() notation with an appropriate tag symbol.

As a particular example and the reference implementation for the #,() convention, this SRFI describes an interpretation of the #,() external form as a read-time application.