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docs for new forms and functions in batch-io

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Matthias Felleisen 2010-04-14 22:50:16 -04:00
parent ed21a85d9d
commit 5abf8bb530
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collects/teachpack/2htdp/scribblings/batch-io.scrbl
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@ -1,29 +1,57 @@
#lang scribble/doc
@(require scribble/manual "shared.ss"
(for-label scheme teachpack/2htdp/batch-io))
@(require (for-label scheme teachpack/2htdp/batch-io))
@(require scribble/manual "shared.ss")
@(require scribble/struct)
@; -----------------------------------------------------------------------------
@(define-syntax-rule (reading name ctc s)
@defproc[(@name [f (and/c string? file-exists?)]) @ctc ]{
reads the content of file @scheme[f] and produces it as @s .
The file @scheme[f] must exist and must be located in the same folder
(directory) as the program; otherwise the function signals an error.} )
@teachpack["batch-io"]{Batch Input/Output}
@author{Matthias Felleisen}
@defmodule[#:require-form beginner-require 2htdp/batch-io]
The batch-io teachpack introduces two functions: @scheme[read-file] and
@scheme[write-file]. It facilitates the reading and writing of entire files
in one batch.
The batch-io teachpack introduces several functions and a form for reading
content from files and one function for writing to a file.
@reading[read-file-as-string string?]{a string, including newlines}
@reading[read-file-as-lines (listof string?)]{a list of strings, one per line}
@reading[read-file-as-1strings (listof 1string?)]{a list of one-char strings, one per character}
@defform/subs[#:id read-file-as-csv
#:literals
(turn-row-into)
(read-file-as-csv f-expr clause)
([clause
(turn-row-into row-expr)
])]{
reads the content of file @scheme[f] and produces it as a list of rows.
The file @scheme[f] must be a file of comma-separated values (csv).
It must exist and must be located in the same folder
(directory) as the program; otherwise the function signals an error.
The form comes with one optional clause: @scheme[turn-into-row], which is
described next.}
@defform[(turn-row-into row-expr)
#:contracts
([row-expr (-> (listof (or/c string? number?)) any)])]{
requests that each row is processed by the result of @scheme[row-expr]
before it is added to the result of @scheme[read-file-as-csv].}
@defproc[(read-file [f (and/c string? file-exists?)]) string?]{
reads the content of file @scheme[f], located in the samd folder
(directory) as the program, and produces it as a string. If @scheme[f]
doesn't exist, the function signals an error.
}
@defproc[(write-file [f string?] [cntnt string?]) boolean?]{
turns @scheme[cntnt] into the content of file @scheme[f], located in the
same folder (directory) as the program. If the file exists when the
function is called, the function produces @scheme[true]; otherwise it
produces @scheme[false].}