The Standard ML Basis Library

The TEXT_STREAM_IO signature


signature TEXT_STREAM_IO

The signature TEXT_STREAM_IO extends the STREAM_IO signature to accommodate text I/O. In particular, it binds the I/O element to Char.char, and provides several text-based I/O operations.


include STREAM_IO
  where type vector = CharVector.vector
  where type elem = Char.char
val inputLine : instream -> (string * instream) option
val outputSubstr : outstream * substring -> unit


inputLine strm
returns SOME(ln, strm'), where ln is the next line of input in the stream strm and strm' is the residual stream. Specifically, ln returns all characters from the current position up to and including the next newline (#"\n") character. If it detects an end-of-stream before the next newline, it returns the characters read appended with a newline. Thus, ln is guaranteed to always be new-line terminated (and thus nonempty). If the current stream position is the end-of-stream, then it returns NONE. It raises Size if the length of the line exceeds the length of the longest string.

outputSubstr (strm, ss)
outputs the substring ss to the text stream strm. This is equivalent to:
output (strm, Substring.string ss)

See Also


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Generated April 12, 2004
Last Modified July 1, 2002
Comments to John Reppy.

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