diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/expr.n | 30 |
1 files changed, 14 insertions, 16 deletions
@@ -5,10 +5,10 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: expr.n,v 1.11 2003/07/04 22:22:07 dkf Exp $ +'\" RCS: @(#) $Id: expr.n,v 1.12 2003/09/12 23:55:32 dkf Exp $ '\" .so man.macros -.TH expr n 8.4 Tcl "Tcl Built-In Commands" +.TH expr n 8.5 Tcl "Tcl Built-In Commands" .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME @@ -55,12 +55,10 @@ If no numeric interpretation is possible, then an operand is left as a string (and only a limited set of operators may be applied to it). .PP -.VS 8.4 On 32-bit systems, integer values MAX_INT (0x7FFFFFFF) and MIN_INT (-0x80000000) will be represented as 32-bit values, and integer values outside that range will be represented as 64-bit values (if that is possible at all.) -.VE 8.4 .PP Operands may be specified in any of the following ways: .IP [1] @@ -117,6 +115,12 @@ Unary minus, unary plus, bit-wise NOT, logical NOT. None of these operands may be applied to string operands, and bit-wise NOT may be applied only to integers. .TP 20 +\fB**\fR +.VS 8.5 +Exponentiation. None of these operands may be applied to string +operands. +.VE 8.5 +.TP 20 \fB*\0\0/\0\0%\fR Multiply, divide, remainder. None of these operands may be applied to string operands, and remainder may be applied only @@ -140,12 +144,10 @@ in which case string comparison is used. \fB==\0\0!=\fR Boolean equal and not equal. Each operator produces a zero/one result. Valid for all operand types. -.VS 8.4 .TP 20 \fBeq\0\0ne\fR Boolean string equal and string not equal. Each operator produces a zero/one result. The operand types are interpreted only as strings. -.VE 8.4 .TP 20 \fB&\fR Bit-wise AND. Valid for integer operands only. @@ -173,6 +175,11 @@ The \fIx\fR operand must have a numeric value. .LP See the C manual for more details on the results produced by each operator. +.VS 8.5 +The exponentiation operator promotes types like the multiply and +divide operators, and produces a result that is the same as the output +of the \fBpow\fR function (after any type conversions.) +.VE 8.5 All of the binary operators group left-to-right within the same precedence level. For example, the command .CS @@ -261,13 +268,11 @@ Computes the length of the hypotenuse of a right-angled triangle \fBsqrt(\fIx\fR*\fIx\fR+\fIy\fR*\fIy\fB)\fR. .TP \fBint(\fIarg\fB)\fR -.VS 8.4 If \fIarg\fR is an integer value of the same width as the machine word, returns \fIarg\fR, otherwise converts \fIarg\fR to an integer (of the same size as a machine word, i.e. 32-bits on 32-bit systems, and 64-bits on 64-bit systems) by truncation and returns the converted value. -.VE 8.4 .TP \fBlog(\fIarg\fB)\fR Returns the natural logarithm of \fIarg\fR. \fIArg\fR must be a @@ -316,10 +321,8 @@ Returns the tangent of \fIarg\fR, measured in radians. Returns the hyperbolic tangent of \fIarg\fR. .TP \fBwide(\fIarg\fB)\fR -.VS 8.4 Converts \fIarg\fR to an integer value at least 64-bits wide (by sign-extension if \fIarg\fR is a 32-bit number) if it is not one already. -.VE 8.4 .PP In addition to these predefined functions, applications may define additional functions using \fBTcl_CreateMathFunc\fR(). @@ -365,9 +368,7 @@ returns \fB4.0\fR, not \fB4\fR. String values may be used as operands of the comparison operators, although the expression evaluator tries to do comparisons as integer or floating-point when it can, -.VS 8.4 except in the case of the \fBeq\fR and \fBne\fR operators. -.VE 8.4 If one of the operands of a comparison is a string and the other has a numeric value, the numeric operand is converted back to a string using the C \fIsprintf\fR format specifier @@ -384,10 +385,7 @@ Because of Tcl's tendency to treat values as numbers whenever possible, it isn't generally a good idea to use operators like \fB==\fR when you really want string comparison and the values of the operands could be arbitrary; it's better in these cases to use -.VS 8.4 -the \fBeq\fR or \fBne\fR operators, or -.VE 8.4 -the \fBstring\fR command instead. +the \fBeq\fR or \fBne\fR operators, or the \fBstring\fR command instead. .SH "PERFORMANCE CONSIDERATIONS" .PP |