Module optparser
This module does parser-based optimizations.
Notes:
- The processing load is quite significant, but since this is an off-line text processor, I believe we can wait a few seconds.
- TODO: Might process "local a,a,a" wrongly... need tests!
- TODO: Remove position handling if overlapped locals (rem < 0) needs more study, to check behaviour.
- TODO: There are probably better ways to do allocation, e.g. by choosing better methods to sort and pick locals...
- TODO: We don't need 53*63 two-letter identifiers; we can make do with significantly less depending on how many that are really needed and improve entropy; e.g. 13 needed -> choose 4*4 instead.
Functions
| optimize (option, _toklist, _seminfolist, xinfo) | The main entry point. |
Local Functions
| preprocess (infotable) | Preprocesses information table to get lists of unique names. |
| recalc_for_entropy (option) | Calculates actual symbol frequencies, in order to reduce entropy. |
| new_var_name () | Returns a string containing a new local variable name to use, and a flag indicating whether it collides with a global variable. |
| stats_summary (globaluniq, localuniq, afteruniq, option) | Calculates and prints some statistics. |
| optimize_func1 () | Does experimental optimization for f("string") statements. |
| optimize_locals (option) | Does local variable optimization. |
Functions
- optimize (option, _toklist, _seminfolist, xinfo)
-
The main entry point.
Parameters:
- option table
- _toklist {string,...}
- _seminfolist {string,...}
- xinfo table
Local Functions
- preprocess (infotable)
-
Preprocesses information table to get lists of unique names.
Parameters:
- infotable {table,...}
Returns:
- recalc_for_entropy (option)
-
Calculates actual symbol frequencies, in order to reduce entropy.
- This may help further reduce the size of compressed sources.
- Note that since parsing optimizations is put before lexing optimizations, the frequency table is not exact!
- Yes, this will miss --keep block comments too...
Parameters:
- option table
- new_var_name ()
-
Returns a string containing a new local variable name to use, and
a flag indicating whether it collides with a global variable.
Trapping keywords and other names like 'self' is done elsewhere.
Returns:
- string A new local variable name.
- bool Whether the name collides with a global variable.
- stats_summary (globaluniq, localuniq, afteruniq, option)
-
Calculates and prints some statistics.
Note: probably better in main source, put here for now.
Parameters:
- optimize_func1 ()
-
Does experimental optimization for f("string") statements.
It's safe to delete parentheses without adding whitespace, as both kinds of strings can abut with anything else.
- optimize_locals (option)
-
Does local variable optimization.
Parameters:
- option {[string]=bool,...}