[r6rs-discuss] [Formal] Port predicates

---
This message is a formal comment which was submitted to formal-comment_at_r6rs.org, following the requirements described at: http://www.r6rs.org/process.html
---
Submitter: John Cowan
Email address: cowan_at_ccil.org
Issue type: Enhancement
Priority: Minor
Component: I/O
Report version: 5.92
Summary:  New predicates wanted for different subtypes of ports
Currently R5.92RS has input-port? and output-port? and binary-port?
I propose adding textual-port?, input/output-port?, file-port?,
string-port?, and bytevector-port? with the obvious semantics.
A textual-port? predicate would be technically redundant, as by
the letter of R5.92RS all non-binary ports are textual; however,
a particular implementation might add ports which were neither
binary nor (in the general sense) textual, with new input or output
operations.
-- 
John Cowan  cowan_at_ccil.org  http://ccil.org/~cowan
If I have seen farther than others, it is because I was standing on
the shoulders of giants.
        --Isaac Newton