Stack usage behaviour

[Tim Channon <tc@...>]

Can someone please clarify fundamental stack behaviour.

I am writing a significant Lua binary library.

abc = mylib(table)

On entry to the C the Lua stack contains one parameter item.

On return from C there is one new item created by the C library.

Behaviour question:- Should the C remove the original item or leave it
in place? (if left in place, what parameter count should be returned?)

All working nicely so far.
Parses trace of graphics plot supplied as PNG into table of numbers,
optionally rescaling x and y axis to requested ranges.
I have yet to decide whether to include the associated simple OCR
(currently in Lua, to be recoded) which is in daily usage reading
autoscaled plot axis. (provides the requested axis range)