diff options
Diffstat (limited to 'doc/expr.n')
| -rw-r--r-- | doc/expr.n | 21 |
1 files changed, 15 insertions, 6 deletions
@@ -1,7 +1,7 @@ '\" '\" Copyright (c) 1993 The Regents of the University of California. '\" Copyright (c) 1994-2000 Sun Microsystems, Inc. -'\" Copyright (c) 2005 by Kevin B. Kenny <kennykb@acm.org>. All rights reserved +'\" Copyright (c) 2005 Kevin B. Kenny <kennykb@acm.org>. All rights reserved '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. @@ -41,6 +41,12 @@ When an expression evaluates to an integer, the value is the decimal form of the integer, and when an expression evaluates to a floating-point number, the value is the form produced by the \fB%g\fR format specifier of Tcl's \fBformat\fR command. +.PP +.VS "TIP 582" +You can use \fB#\fR at any point in the expression (except inside double +quotes or braces) to start a comment. Comments last to the end of the line or +the end of the expression, whichever comes first. +.VE "TIP 582" .SS OPERANDS .PP An expression consists of a combination of operands, operators, parentheses and @@ -82,9 +88,9 @@ produces the value on the right side. .PP .CS .ta 9c -\fBexpr\fR 3.1 + $a \fI6.1\fR -\fBexpr\fR 2 + "$a.$b" \fI5.6\fR -\fBexpr\fR 4*[llength "6 2"] \fI8\fR +\fBexpr\fR {3.1 + $a} \fI6.1\fR +\fBexpr\fR {2 + "$a.$b"} \fI5.6\fR +\fBexpr\fR {4*[llength "6 2"]} \fI8\fR \fBexpr\fR {{word one} < "word $a"} \fI0\fR .CE .PP @@ -270,7 +276,7 @@ which means that operands are not evaluated if they are not needed to determine the outcome. For example, in .PP .CS -\fBexpr\fR {$v ? [a] : [b]} +\fBexpr\fR {$v?[a]:[b]} .CE .PP only one of \fB[a]\fR or \fB[b]\fR is evaluated, @@ -487,7 +493,9 @@ value of true: .PP .CS set isTrue [\fBexpr\fR { + # Does the environment variable exist, and... [info exists ::env(SOME_ENV_VAR)] && + # ...does it contain a proper true value? [string is true -strict $::env(SOME_ENV_VAR)] }] .CE @@ -506,8 +514,9 @@ arithmetic, boolean, compare, expression, fuzzy comparison, integer value .nf Copyright \(co 1993 The Regents of the University of California. Copyright \(co 1994-2000 Sun Microsystems Incorporated. -Copyright \(co 2005 by Kevin B. Kenny <kennykb@acm.org>. All rights reserved. +Copyright \(co 2005 Kevin B. Kenny <kennykb@acm.org>. All rights reserved. .fi '\" Local Variables: '\" mode: nroff +'\" fill-column: 78 '\" End: |