[TCLCORE] New internal list representations

[<apn...@ya...>]

https://core.tcl-lang.org/tcl/wiki?name=New+abstract+list+representations
<https://core.tcl-lang.org/tcl/wiki?name=New+abstract+list+representations&p
> &p is a proposal to implement some list operations using new internal list
representations enabled by Brian's TIP 636. The wiki post has the full
details but TL;DR memory efficiency at a small (probably fixable) cost in
iteration speed for large lists. The post has the numbers.

 

The apn-tip636-appl branch contains the implementation of the proposal. The
listTypes.test file contains the test cases to exercise the three new
internal list types as well as the existing ones. Passes -enable-symbols=mem
and valgrind OMM. gcov shows 91% code and 100% function coverage of the new
implementation. Missing coverage is for "panic blocks" and validation which
is not exercised as it is already done by upper callers.

 

Not planning a TIP as there are no changes at the script or C API level.

 

Please review (both proposal and code) and raise any objections you may
have. (It's not that much code to review and pretty isolated thanks to 636).

 

/Ashok