Implement defer, $jim::defer

Allows commands to run when a proc or interpreter exits.

If the $jim::defer variables exists at proc or interp exit,
it is treated as a list of scripts to evaluate (in reverse order).

The [defer] command is a helper to add scripts to $jim::defer

See tests/defer.test

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 7 insertions, 0 deletions

diff --git a/stdlib.tcl b/stdlib.tcl
index 7fd1313..37a8007 100644
--- a/stdlib.tcl
+++ b/stdlib.tcl
@@ -66,6 +66,13 @@ proc stackdump {stacktrace} {
 	join $lines \n
 }
 
+# Add the given script to $jim::defer, to be evaluated when the current
+# procedure exits
+proc defer {script} {
+	upvar jim::defer v
+	lappend v $script
+}
+
 # Sort of replacement for $::errorInfo
 # Usage: errorInfo error ?stacktrace?
 proc errorInfo {msg {stacktrace ""}} {