From: Ian Jackson <ian@liberator.relativity.greenend.org.uk>
Date: Sun, 2 Jan 2011 13:27:39 +0000 (+0000)
Subject: hostside/lib.tcl: new setexpr and addexpr commands
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=c4295c0308d5d69c9bd7230c46a0e92674bee55d;p=trains.git

hostside/lib.tcl: new setexpr and addexpr commands
---

diff --git a/hostside/lib.tcl b/hostside/lib.tcl
index a0f711a..a1ec562 100644
--- a/hostside/lib.tcl
+++ b/hostside/lib.tcl
@@ -74,5 +74,17 @@ proc get-unique {prefix} {
     return "$prefix[incr ix]"
 }
 
+proc addexpr {varname expr} {
+    set add [uplevel 1 expr $expr]
+    upvar 1 $varname var
+    if {![info exists var]} { set var 0 }
+    set var [expr {$var + $add}]
+}
+
+proc setexpr {varname expr} {
+    upvar 1 $varname var
+    set var [uplevel 1 expr $expr]
+}
+
 setting port 2883 {\d+}