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#
#	File:     signed.icn
#
#	Subject:  Procedure to put bits into signed integer
#
#	Author:   Robert J. Alexander
#
#	Date:     April 2, 1990
#
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#
#   This file is in the public domain.
#
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#
#  signed(s,n) -- Puts raw bits of characters of string s into an
#  integer.  The value is taken as signed.
#
#  If large integers are supported, this routine will work for integers
#  of arbitrary size.
#
#  If large integers are not supported, the following are true:
#
#    If the size of s is the same as or greater than the size of an
#    integer in the Icon implementation, the result will be negative or
#    positive depending on the value of the integer's sign bit.
#
#    If the size of s is less than the size of an integer, the bytes are
#    put into the low order part of the integer, with the remaining high
#    order bytes filled with sign bits (the high order bit of the first
#    character of the string).  If the string is too large, the most
#    significant bytes will be lost.
#
#  This procedure is normally used for processing of binary data read
#  from a file.
#

procedure signed(s)
   local i
   i := if ord(s[1]) >= 128 then -1 else 0
   every i := ior(ord(!s),ishift(i,8))
   return i
end