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
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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. If no
114 arguments are given, the result will be one, and if only one
115 argument is given, the result will be that argument. The result
116 will have an integral value only when all arguments are integral
117 values.
118 COMPARISON OPERATORS
120 The behaviors of the comparison operator commands (most of which oper‐
121 ate preferentially on numeric arguments) are as follows:
122 == ?arg ...?
124 Returns whether each argument is equal to the arguments on each
125 side of it in the sense of the expr == operator (i.e., numeric
126 comparison if possible, exact string comparison otherwise). If
127 fewer than two arguments are given, this operation always
128 returns a true value.
129 eq ?arg ...?
131 Returns whether each argument is equal to the arguments on each
132 side of it using exact string comparison. If fewer than two
133 arguments are given, this operation always returns a true value.
134 != arg arg
136 Returns whether the two arguments are not equal to each other,
137 in the sense of the expr != operator (i.e., numeric comparison
138 if possible, exact string comparison otherwise).
139 ne arg arg
141 Returns whether the two arguments are not equal to each other
142 using exact string comparison.
143 < ?arg ...?
145 Returns whether the arbitrarily-many arguments are ordered, with
146 each argument after the first having to be strictly more than
147 the one preceding it. Comparisons are performed preferentially
148 on the numeric values, and are otherwise performed using UNICODE
149 string comparison. If fewer than two arguments are present, this
150 operation always returns a true value. When the arguments are
151 numeric but should be compared as strings, the string compare
152 command should be used instead.
153 <= ?arg ...?
155 Returns whether the arbitrarily-many arguments are ordered, with
156 each argument after the first having to be equal to or more than
157 the one preceding it. Comparisons are performed preferentially
158 on the numeric values, and are otherwise performed using UNICODE
159 string comparison. If fewer than two arguments are present, this
160 operation always returns a true value. When the arguments are
161 numeric but should be compared as strings, the string compare
162 command should be used instead.
163 > ?arg ...?
165 Returns whether the arbitrarily-many arguments are ordered, with
166 each argument after the first having to be strictly less than
167 the one preceding it. Comparisons are performed preferentially
168 on the numeric values, and are otherwise performed using UNICODE
169 string comparison. If fewer than two arguments are present, this
170 operation always returns a true value. When the arguments are
171 numeric but should be compared as strings, the string compare
172 command should be used instead.
173 >= ?arg ...?
175 Returns whether the arbitrarily-many arguments are ordered, with
176 each argument after the first having to be equal to or less than
177 the one preceding it. Comparisons are performed preferentially
178 on the numeric values, and are otherwise performed using UNICODE
179 string comparison. If fewer than two arguments are present, this
180 operation always returns a true value. When the arguments are
181 numeric but should be compared as strings, the string compare
182 command should be used instead.
183 BIT-WISE OPERATORS
185 The behaviors of the bit-wise operator commands (all of which only
186 operate on integral arguments) are as follows:
187 ~ number
189 Returns the bit-wise negation of number. Number may be an inte‐
190 ger of any size. Note that the result of this operation will
191 always have the opposite sign to the input number.
192 & ?number ...?
194 Returns the bit-wise AND of each of the arbitrarily many argu‐
195 ments. Each number must have an integral value. If no arguments
196 are given, the result will be minus one.
197 | ?number ...?
199 Returns the bit-wise OR of each of the arbitrarily many argu‐
200 ments. Each number must have an integral value. If no arguments
201 are given, the result will be zero.
202 ^ ?number ...?
204 Returns the bit-wise XOR of each of the arbitrarily many argu‐
205 ments. Each number must have an integral value. If no arguments
206 are given, the result will be zero.
207 << number number
209 Returns the result of bit-wise shifting the first argument left
210 by the number of bits specified in the second argument. Each
211 number must have an integral value.
212 >> number number
214 Returns the result of bit-wise shifting the first argument right
215 by the number of bits specified in the second argument. Each
216 number must have an integral value.
217 LIST OPERATORS
219 The behaviors of the list-oriented operator commands are as follows:
220 in arg list
222 Returns whether the value arg is present in the list list
223 (according to exact string comparison of elements).
224 ni arg list
226 Returns whether the value arg is not present in the list list
227 (according to exact string comparison of elements).
228
230 The simplest way to use the operators is often by using namespace path
231 to make the commands available. This has the advantage of not affecting
232 the set of commands defined by the current namespace.
233 namespace path {::tcl::mathop ::tcl::mathfunc}
235 # Compute the sum of some numbers
237 set sum [+ 1 2 3]
238 # Compute the average of a list
240 set list {1 2 3 4 5 6}
241 set mean [/ [+ {*}$list] [double [llength $list]]]
242 # Test for list membership
244 set gotIt [in 3 $list]
245 # Test to see if a value is within some defined range
247 set inRange [<= 1 $x 5]
248 # Test to see if a list is sorted
250 set sorted [<= {*}$list]
251
253 expr(n), mathfunc(n), namespace(n)
254
256 command, expression, operator
257Tcl 8.5 mathop(n)