The IOUtil structure

The IOUtil structure provides support for redirecting the standard input and output streams.

Synopsis

signature IO_UTIL
structure IOUtil : IO_UTIL

Interface

val withInputFile : string * ('a -> 'b) -> 'a -> 'b
val withInstream : TextIO.instream * ('a -> 'b) -> 'a -> 'b

val withOutputFile : string * ('a -> 'b) -> 'a -> 'b
val withOutstream : TextIO.outstream * ('a -> 'b) -> 'a -> 'b

Description

val withInputFile : string * ('a -> 'b) -> 'a -> 'b

withInputFile (file, f) x evaluates the expression f x with standard input bound to file. The file is closed and the TextIO.stdIn input stream is restored to its original binding once evaluation terminates.

val withInstream : TextIO.instream * ('a -> 'b) -> 'a -> 'b

withInstream (inS, f) x evaluates the expression f x with standard output redirected to inS. The TextIO.stdIn input stream is restored to its original binding once evaluation terminates.

val withOutputFile : string * ('a -> 'b) -> 'a -> 'b

withOutputFile (file, f) x evaluates the expression f x with standard output redirected to file. The file is closed and the TextIO.stdOut output stream is restored to its original destination once evaluation terminates.

val withOutstream : TextIO.outstream * ('a -> 'b) -> 'a -> 'b

withOutstream (outS, f) x evaluates the expression f x with standard output redirected to outS. The TextIO.stdOut output stream is restored to its original destination once evaluation terminates.

Example

The following expression will put its output in the file "hello.txt":

withOutputFile ("hello.txt", fn () => print "hello world\n") ()

See Also

The Util Library