[r6rs-discuss] [Formal] Port predicates

[cowan at ccil.org]

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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