Pretty Encoding

[Ayplow]

Related to #11

This is my shot at an efficient pretty encoding facility. I'm happy to implement any changes that could improve performance.

• A cache is built from the cache argument, avoiding recreation of indent strings. This will consume memory (that will be released with the encoder), however the footprint is minimal
• Any encoders with the same indent share a cache. Only one assignment is made on depth change.
• space is equivalent to the third argument of javascript's JSON.stringify

[tst2005]

You are using _ENV... is your changes breaks the Lua 5.1 compat ?

[Ayplow]

Hah right, forgot to write the compat. I'll get on that

[tst2005]

Can't you just use a local table items instead of separated variables in _ENV ?

for sample

local config
...
-builder[i] = start_array
+builder[i] = config.start_array
...
- 	if type(space) ~= "string" or space == "" then _ENV = basic else
+ 	if type(space) ~= "string" or space == "" then config = basic else

and just avoid to use _ENV and ugly compat ?

[tst2005]

• do you use somewhere the f_string_esc_pat introduce with the lua 5.1 compat ?
• do you lost the original local _ENV = nil ? (I don't know if it is really important)

[Ayplow]

The string escape pattern is used in f_string? I don't understand what you mean.