warn about missing context chars in register-event

diff --git a/hostside/gui b/hostside/gui
index c0ecf25694f36fe5270a8f70da85ccb7c6598f71..4dbe01a120b1a0e80bb9356f3e82361f89a37c68 100755 (executable)
--- a/hostside/gui
+++ b/hostside/gui
@@ -49,7 +49,16 @@ proc register-event {selections args re body} {
     global event_dispatch_body event_selections
 
     eval lappend event_selections $selections
-       
+
+    foreach selection $selections {
+       if {[regexp {^\w} $selection]} {
+           error "selection $selection lacks context char"
+       }
+    }
+    if {[regexp {^\^\w} $re]} {
+       error "re $re never matches context char"
+    }
+
     regsub -all {\W+} $re - proc
     set proc "event/$proc/[join $args -]"
     set suffix {}
@@ -463,7 +472,7 @@ proc train-event-eof {args} {
     error "lost connection to train set"
 }
 
-register-event stastate {state} \
+register-event ?stastate {state} \
        {^.stastate (\w+|\-) } {
     global ctrain trains statstate