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authordkf <donal.k.fellows@manchester.ac.uk>2003-09-12 23:55:32 (GMT)
committerdkf <donal.k.fellows@manchester.ac.uk>2003-09-12 23:55:32 (GMT)
commitda60f636030ff5e28efdfe34eb534c9dd46e2fb3 (patch)
tree2f2c7e65505a410bb72e9cc37de0a6baab73939f /doc
parent15cd6e14858186b0fc6748418f0c92ee5c1495ab (diff)
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TIP#123 Implementation based on work by Arjen Markus. [Patch 655176]
Diffstat (limited to 'doc')
-rw-r--r--doc/expr.n30
1 files changed, 14 insertions, 16 deletions
diff --git a/doc/expr.n b/doc/expr.n
index 8508ee2..b7425f1 100644
--- a/doc/expr.n
+++ b/doc/expr.n
@@ -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