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add some examples for port functions

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This commit is contained in:
Jon Rafkind 2010-10-27 12:39:21 -06:00
parent 5633895cf0
commit f21a15aef1
1 changed files with 32 additions and 5 deletions
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37
collects/scribblings/reference/port-lib.scrbl
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@ -9,19 +9,37 @@
@; ----------------------------------------------------------------------
@section{Port String and List Conversions}
@(define port-eval (make-base-eval))
@(interaction-eval #:eval port-eval (require racket/port))
@defproc[(port->list [r (input-port? . -> . any/c) read] [in input-port? (current-input-port)])
(listof any/c)]{
Returns a list whose elements are produced by calling @scheme[r]
on @scheme[in] until it produces @scheme[eof].}
on @scheme[in] until it produces @scheme[eof].
@examples[#:eval port-eval
(define (read-number input-port)
(define char (read-char input-port))
(if (eof-object? char)
char
(string->number (string char))))
(port->list read-number (open-input-string "12345"))
]}
@defproc[(port->string [in input-port? (current-input-port)]) string?]{
Reads all characters from @scheme[in] and returns them as a string.}
Reads all characters from @scheme[in] and returns them as a string.
@examples[#:eval port-eval
(port->string (open-input-string "hello world"))
]}
@defproc[(port->bytes [in input-port? (current-input-port)]) bytes?]{
Reads all bytes from @scheme[in] and returns them as a @tech{byte string}.}
Reads all bytes from @scheme[in] and returns them as a @tech{byte string}.
@examples[#:eval port-eval
(port->bytes (open-input-string "hello world"))
]}
@defproc[(port->lines [in input-port? (current-input-port)]
[#:line-mode line-mode (or/c 'linefeed 'return 'return-linefeed 'any 'any-one) 'any])
@ -30,14 +48,22 @@ Reads all bytes from @scheme[in] and returns them as a @tech{byte string}.}
Read all characters from @scheme[in], breaking them into lines. The
@scheme[line-mode] argument is the same as the second argument to
@scheme[read-line], but the default is @scheme['any] instead of
@scheme['linefeed].}
@scheme['linefeed].
@examples[#:eval port-eval
(port->lines (open-input-string "line 1\nline 2\n line 3\nline 4"))
]}
@defproc[(port->bytes-lines [in input-port? (current-input-port)]
[#:line-mode line-mode (or/c 'linefeed 'return 'return-linefeed 'any 'any-one) 'any])
(listof bytes?)]{
Like @scheme[port->lines], but reading bytes and collecting them into
lines like @scheme[read-bytes-line].}
lines like @scheme[read-bytes-line].
@examples[#:eval port-eval
(port->bytes-lines (open-input-string "line 1\nline 2\n line 3\nline 4"))
]}
@defproc[(display-lines [lst list?]
[out output-port? (current-output-port)]
@ -689,3 +715,4 @@ is written completely to one @scheme[out] before moving to the next
non-blocking ports (e.g., to a file) should be placed first in the
argument list.}
@close-eval[port-eval]