SML/NJ: getting user input

Question

How do I prompt for user input while a function is running?

score 5 · Answer 1 · edited Jul 28 '14 at 16:23

5

To read a line from standard input use TextIO.inputLine from the Standard Basis Library, I think you can just do something like

TextIO.inputLine TextIO.stdIn

Clarification: this returns a string option type, which is NONE if it is at EOF

edited Jul 28 '14 at 16:23

ben rudgers

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answered Apr 23 '10 at 05:39

newacct

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1

You might need to valOf the result, as TextIO.inputLine returns a string option. – Martin Törnwall Jul 12 '11 at 19:37

score 5 · Answer 2 · answered Apr 23 '10 at 06:01

My code looks something like this:

fun get infile = ( TextIO.output(TextIO.stdOut, prompt)
                 ; TextIO.flushOut(TextIO.stdOut)
                 ; TextIO.inputLine infile
                 )

This returns a value of type string option; normally a line SOME l, but NONE on end of file.

SML/NJ: getting user input

2 Answers2