integer.rb in ruby-vpi-16.0.0

- old
+ new

@@ -1,26 +1,13 @@
-=begin
-  Copyright 2006 Suraj N. Kurapati
+# Library for hardware-related integer operations.
+#--
+# Copyright 2006-2007 Suraj N. Kurapati
+# See the file named LICENSE for details.
 
-  This file is part of Ruby-VPI.
-
-  Ruby-VPI is free software; you can redistribute it and/or
-  modify it under the terms of the GNU General Public License
-  as published by the Free Software Foundation; either version 2
-  of the License, or (at your option) any later version.
-
-  Ruby-VPI is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with Ruby-VPI; if not, write to the Free Software Foundation,
-  Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
-=end
-
-# NOTE: Because integers are _immediate_ values in Ruby, these methods *cannot* modify the value of the integer upon which they are invoked. Instead, they return the new value as their result.
+# NOTE: Because integers are _immediate_ values in Ruby, these methods *cannot*
+# modify the value of the integer upon which they are invoked. Instead, they
+# return the new value as their result.
 class Integer
   # Returns the ceiling of the logarithm (base 2) of this positive integer.
   def log2
     raise "integer must be positive" if self < 0
     bin = to_s(2)
@@ -35,11 +22,12 @@
   # Returns the minimum number of bits necessary to represent this integer.
   def length
     to_s(2).length
   end
 
-  # Returns the lowest upper-bound of this integer. This integer cannot reach the limit without occupying more bits in its binary representation.
+  # Returns the lowest upper-bound of this integer. This integer cannot reach
+  # the limit without occupying more bits in its binary representation.
   def limit
     length.to_limit
   end
 
   # Returns the lowest upper-bound of an integer with *this* number of bits.
@@ -57,37 +45,22 @@
   def to_mask
     to_limit - 1
   end
 
 
-  # Returns the maximum value representable by this integer without occupying more bits in its binary representation.
+  # Returns the maximum value representable by this integer without occupying
+  # more bits in its binary representation.
   alias max mask
 
-  # Returns the maximum value representable by an integer with *this* number of bits.
+  # Returns the maximum value representable by an integer with *this* number of
+  # bits.
   alias to_max to_mask
 
 
-  # Ensures that this integer is no less than the given limit.
-  def ensure_min aLimit
-    if self < aLimit
-      aLimit
-    else
-      self
-    end
-  end
-
-  # Ensures that this integer is no greater than the given limit.
-  def ensure_max aLimit
-    if self > aLimit
-      aLimit
-    else
-      self
-    end
-  end
-
-
-  # Transforms this infinite-length Ruby integer into a fixed-length integer (represented in two's complement form) that has the given width (number of bits).
+  # Transforms this infinite-length Ruby integer into a fixed-length integer
+  # (represented in two's complement form) that has the given width (number of
+  # bits).
   def pack aPackedWidth
     bits = length
     bits += 1 if self > 0 # positive integers also have a sign bit (zero)
 
     unless aPackedWidth >= bits
@@ -95,11 +68,13 @@
     end
 
     extend_sign(bits, aPackedWidth)
   end
 
-  # Transforms this fixed-length integer (represented in two's complement form) that has the given width (number of bits) into an infinite-length Ruby integer.
+  # Transforms this fixed-length integer (represented in two's complement form)
+  # that has the given width (number of bits) into an infinite-length Ruby
+  # integer.
   def unpack aPackedWidth
     bits = length
 
     unless aPackedWidth >= bits
       raise ArgumentError, "packed width #{aPackedWidth} must be at least #{bits} for integer #{self}"
@@ -114,11 +89,13 @@
       result
     end
   end
 
 
-  # Performs sign extension on this integer, which has the given width (number of bits), so that the result will have the given extended width (number of bits).
+  # Performs sign extension on this integer, which has the given width (number
+  # of bits), so that the result will have the given extended width (number of
+  # bits).
   def extend_sign aOrigWidth, aExtWidth
     result = self
     maskWidth = aExtWidth - aOrigWidth
 
     if maskWidth > 0 && result[aOrigWidth - 1] == 1
@@ -126,10 +103,13 @@
     end
 
     result & aExtWidth.to_mask
   end
 
-  # Splits this integer into an array of smaller integers, each of which have the given positive, non-zero width (number of bits). These smaller integers are ordered from left to right, in the same way that humans write unsigned binary numbers; for example:
+  # Splits this integer into an array of smaller integers, each of which have
+  # the given positive, non-zero width (number of bits). These smaller integers
+  # are ordered from left to right, in the same way that humans write unsigned
+  # binary numbers; for example:
   #
   ## >> 6.split 1
   ## => [1, 1, 0]
   ## >> 6.split(1).map {|i| i.to_s 2}
   ## => ["1", "1", "0"]