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Module: IO
Function: hLookAhead
Type: Handle -> IO Char
Description: hLookAhead hdl returns the next character from handle hdl without removing it from the input buffer, blocking until a character is available
Related:

Example 1
File: /tmp/foo.txt : 

Hello, world!
How do you do?

Program source: 

import IO

main = do x <- openFile "/tmp/foo.txt" ReadMode
	  y <- hLookAhead x
          putChar y
          y <- hLookAhead x
          putChar y
          y <- hGetChar x
          putChar y
          y <- hLookAhead x
          putChar y

Output: HHHe