8.6 Control Structures – NRE

Miguel’s NRE (Non-Recursive Engine) – Decouples Tcl and C stacks from each other. Enables:

[327] tailcall

Tailcall – Similar to uplevel. Differences: Replaces the calling stackframe. Argument is not a script → No double substitution. Resolution in the current context, not the caller.

tailcall foo [bar] $var

return [uplevel 1 [list foo [bar] $var1]]