1mathop(n) Tcl Mathematical Operator Commands mathop(n)
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8 mathop - Mathematical operators as Tcl commands
9
11 package require Tcl 8.5
12 ::tcl::mathop::! number
14 ::tcl::mathop::~ number
15 ::tcl::mathop::+ ?number ...?
16 ::tcl::mathop::- number ?number ...?
17 ::tcl::mathop::* ?number ...?
18 ::tcl::mathop::/ number ?number ...?
19 ::tcl::mathop::% number number
20 ::tcl::mathop::** ?number ...?
21 ::tcl::mathop::& ?number ...?
22 ::tcl::mathop::| ?number ...?
23 ::tcl::mathop::^ ?number ...?
24 ::tcl::mathop::<< number number
25 ::tcl::mathop::>> number number
26 ::tcl::mathop::== ?arg ...?
27 ::tcl::mathop::!= arg arg
28 ::tcl::mathop::< ?arg ...?
29 ::tcl::mathop::<= ?arg ...?
30 ::tcl::mathop::>= ?arg ...?
31 ::tcl::mathop::> ?arg ...?
32 ::tcl::mathop::eq ?arg ...?
33 ::tcl::mathop::ne arg arg
34 ::tcl::mathop::in arg list
35 ::tcl::mathop::ni arg list
36______________________________________________________________________________
38
40 The commands in the ::tcl::mathop namespace implement the same set of
41 operations as supported by the expr command. All are exported from the
42 namespace, but are not imported into any other namespace by default.
43 Note that renaming, reimplementing or deleting any of the commands in
44 the namespace does not alter the way that the expr command behaves, and
45 nor does defining any new commands in the ::tcl::mathop namespace.
46 The following operator commands are supported:
48 ~ ! + - *
50 / % ** & |
51 ^ >> << == eq
52 != ne < <= >
53 >= in ni
54 MATHEMATICAL OPERATORS
57 The behaviors of the mathematical operator commands are as follows:
58 ! boolean
60 Returns the boolean negation of boolean, where boolean may be
61 any numeric value or any other form of boolean value (i.e. it
62 returns truth if the argument is falsity or zero, and falsity if
63 the argument is truth or non-zero).
64 + ?number ...?
66 Returns the sum of arbitrarily many arguments. Each number argu‐
67 ment may be any numeric value. If no arguments are given, the
68 result will be zero (the summation identity).
69 - number ?number ...?
71 If only a single number argument is given, returns the negation
72 of that numeric value. Otherwise returns the number that results
73 when all subsequent numeric values are subtracted from the first
74 one. All number arguments must be numeric values. At least one
75 argument must be given.
76 * ?number ...?
78 Returns the product of arbitrarily many arguments. Each number
79 may be any numeric value. If no arguments are given, the result
80 will be one (the multiplicative identity).
81 / number ?number ...?
83 If only a single number argument is given, returns the recipro‐
84 cal of that numeric value (i.e. the value obtained by dividing
85 1.0 by that value). Otherwise returns the number that results
86 when the first numeric argument is divided by all subsequent
87 numeric arguments. All number arguments must be numeric values.
88 At least one argument must be given.
89 Note that when the leading values in the list of arguments are
91 integers, integer division will be used for those initial steps
92 (i.e. the intermediate results will be as if the functions floor
93 and int are applied to them, in that order). If all values in
94 the operation are integers, the result will be an integer.
95 % number number
97 Returns the integral modulus (i.e., remainder) of the first
98 argument with respect to the second. Each number must have an
99 integral value. Also, the sign of the result will be the same
100 as the sign of the second number, which must not be zero.
101 Note that Tcl defines this operation exactly even for negative
103 numbers, so that the following command returns a true value
104 (omitting the namespace for clarity):
105 == [* [/ x y] y] [- x [% x y]]
107 ** ?number ...?
109 Returns the result of raising each value to the power of the
110 result of recursively operating on the result of processing the
111 following arguments, so “** 2 3 4” is the same as “** 2 [** 3
112 4]”. Each number may be any numeric value, though the second
113 number must not be fractional if the first is negative. The
114 maximum exponent value that Tcl can handle if the first number
115 is an integer > 1 is 268435455. If no arguments are given, the
116 result will be one, and if only one argument is given, the
117 result will be that argument. The result will have an integral
118 value only when all arguments are integral values.
119 COMPARISON OPERATORS
121 The behaviors of the comparison operator commands (most of which oper‐
122 ate preferentially on numeric arguments) are as follows:
123 == ?arg ...?
125 Returns whether each argument is equal to the arguments on each
126 side of it in the sense of the expr == operator (i.e., numeric
127 comparison if possible, exact string comparison otherwise). If
128 fewer than two arguments are given, this operation always
129 returns a true value.
130 eq ?arg ...?
132 Returns whether each argument is equal to the arguments on each
133 side of it using exact string comparison. If fewer than two
134 arguments are given, this operation always returns a true value.
135 != arg arg
137 Returns whether the two arguments are not equal to each other,
138 in the sense of the expr != operator (i.e., numeric comparison
139 if possible, exact string comparison otherwise).
140 ne arg arg
142 Returns whether the two arguments are not equal to each other
143 using exact string comparison.
144 < ?arg ...?
146 Returns whether the arbitrarily-many arguments are ordered, with
147 each argument after the first having to be strictly more than
148 the one preceding it. Comparisons are performed preferentially
149 on the numeric values, and are otherwise performed using UNICODE
150 string comparison. If fewer than two arguments are present, this
151 operation always returns a true value. When the arguments are
152 numeric but should be compared as strings, the string compare
153 command should be used instead.
154 <= ?arg ...?
156 Returns whether the arbitrarily-many arguments are ordered, with
157 each argument after the first having to be equal to or more than
158 the one preceding it. Comparisons are performed preferentially
159 on the numeric values, and are otherwise performed using UNICODE
160 string comparison. If fewer than two arguments are present, this
161 operation always returns a true value. When the arguments are
162 numeric but should be compared as strings, the string compare
163 command should be used instead.
164 > ?arg ...?
166 Returns whether the arbitrarily-many arguments are ordered, with
167 each argument after the first having to be strictly less than
168 the one preceding it. Comparisons are performed preferentially
169 on the numeric values, and are otherwise performed using UNICODE
170 string comparison. If fewer than two arguments are present, this
171 operation always returns a true value. When the arguments are
172 numeric but should be compared as strings, the string compare
173 command should be used instead.
174 >= ?arg ...?
176 Returns whether the arbitrarily-many arguments are ordered, with
177 each argument after the first having to be equal to or less than
178 the one preceding it. Comparisons are performed preferentially
179 on the numeric values, and are otherwise performed using UNICODE
180 string comparison. If fewer than two arguments are present, this
181 operation always returns a true value. When the arguments are
182 numeric but should be compared as strings, the string compare
183 command should be used instead.
184 BIT-WISE OPERATORS
186 The behaviors of the bit-wise operator commands (all of which only
187 operate on integral arguments) are as follows:
188 ~ number
190 Returns the bit-wise negation of number. Number may be an inte‐
191 ger of any size. Note that the result of this operation will
192 always have the opposite sign to the input number.
193 & ?number ...?
195 Returns the bit-wise AND of each of the arbitrarily many argu‐
196 ments. Each number must have an integral value. If no arguments
197 are given, the result will be minus one.
198 | ?number ...?
200 Returns the bit-wise OR of each of the arbitrarily many argu‐
201 ments. Each number must have an integral value. If no arguments
202 are given, the result will be zero.
203 ^ ?number ...?
205 Returns the bit-wise XOR of each of the arbitrarily many argu‐
206 ments. Each number must have an integral value. If no arguments
207 are given, the result will be zero.
208 << number number
210 Returns the result of bit-wise shifting the first argument left
211 by the number of bits specified in the second argument. Each
212 number must have an integral value.
213 >> number number
215 Returns the result of bit-wise shifting the first argument right
216 by the number of bits specified in the second argument. Each
217 number must have an integral value.
218 LIST OPERATORS
220 The behaviors of the list-oriented operator commands are as follows:
221 in arg list
223 Returns whether the value arg is present in the list list
224 (according to exact string comparison of elements).
225 ni arg list
227 Returns whether the value arg is not present in the list list
228 (according to exact string comparison of elements).
229
231 The simplest way to use the operators is often by using namespace path
232 to make the commands available. This has the advantage of not affecting
233 the set of commands defined by the current namespace.
234 namespace path {::tcl::mathop ::tcl::mathfunc}
236 # Compute the sum of some numbers
238 set sum [+ 1 2 3]
239 # Compute the average of a list
241 set list {1 2 3 4 5 6}
242 set mean [/ [+ {*}$list] [double [llength $list]]]
243 # Test for list membership
245 set gotIt [in 3 $list]
246 # Test to see if a value is within some defined range
248 set inRange [<= 1 $x 5]
249 # Test to see if a list is sorted
251 set sorted [<= {*}$list]
252
254 expr(n), mathfunc(n), namespace(n)
255
257 command, expression, operator
258Tcl 8.5 mathop(n)