Texas Instruments Titanium TI-89, Руководство пользователя

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Appendix A: Functions and Instructions 847
shift()
CATALOG
shift( integer1[ , #ofShifts] )
⇒
integer
Shifts the bits in a binary integer. You can enter
integer1
in any number base; it is converted
automatically to a signed, 32-bit binary form. If the
magnitude of
integer1
is too large for this form, a
symmetric modulo operation brings it within the
range.
If
#ofShifts
is positive, the shift is to the left. If
#ofShifts
is negative, the shift is to the right. The
default is
ë
1 (shift right one bit).
In a right shift, the rightmost bit is dropped and 0 or
1 is inserted to match the leftmost bit. In a left shift,
the leftmost bit is dropped and 0 is inserted as the
rightmost bit.
For example, in a right shift:
In Bin base mode:
shift(0b1111010110000110101)
¸
0b111101011000011010
shift(256,1)
¸
0b1000000000
In Hex base mode:
shift(0h78E)
¸
0h3C7
shift(0h78E,
ë
2)
¸
0h1E3
shift(0h78E,2) ¸ 0h1E38
Important: To enter a binary or hexadecimal
number, always use the 0b or 0h prefix (zero,
not the letter O).
0b00000000000001111010110000110101
produces:
0b00000000000000111101011000011010
The result is displayed according to the
Base
mode.
Leading zeros are not shown.
shift(
list1 [
,
#ofShifts]
)
⇒
list
Returns a copy of
list1
shifted right or left by
#ofShifts
elements. Does not alter
list1
.
If
#ofShifts
is positive, the shift is to the left. If
#ofShifts
is negative, the shift is to the right. The
default is
ë
1 (shift right one element).
Elements introduced at the beginning or end of
list
by the shift are set to the symbol “undef”.
In Dec base mode:
shift({1,2,3,4})
¸
{undef 1 2 3}
shift({1,2,3,4},
ë
2)
¸
{undef undef 1 2}
shift({1,2,3,4},1) ¸
{2 3 4 undef}
shift( string1 [ , #ofShifts] )
⇒
string
Returns a copy of
string1
shifted right or left by
#ofShifts
characters. Does not alter
string1
.
If
#ofShifts
is positive, the shift is to the left. If
#ofShifts
is negative, the shift is to the right. The
default is
ë
1 (shift right one character).
Characters introduced at the beginning or end of
string by the shift are set to a space.
shift("abcd")
¸
" abc"
shift("abcd",
ë
2)
¸
" ab"
shift("abcd",1) ¸ "bcd "
Inserts 0 if leftmost bit is 0,
or 1 if leftmost bit is 1.
Each bit shifts right.
Dropped