From ff7ec50a94cfa036d1472a9bbb3b8e77d96e60b5 Mon Sep 17 00:00:00 2001
From: XeonSquared <redtailedairways@gmail.com>
Date: Fri, 4 Aug 2023 20:32:42 +1000
Subject: [PATCH] add some simple minification filters to preproc, which can
 shrink the kernel significantly

---
 build.lua   |  2 +-
 preproc.lua | 31 ++++++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/build.lua b/build.lua
index 6bb1576..9f4de05 100644
--- a/build.lua
+++ b/build.lua
@@ -1,4 +1,4 @@
 local preproc = require "preproc"
---local tA = {...}
 
+preproc.minify = true
 preproc(...)
diff --git a/preproc.lua b/preproc.lua
index ba3bce7..8ec5e4b 100644
--- a/preproc.lua
+++ b/preproc.lua
@@ -82,11 +82,40 @@ function preproc.directives.includepkglib(package, file, name) -- string string
  return string.format("package.loaded['%s'] = (function()\n%s\nend)()", name, preproc.directives.includepkgfile(package, file))
 end
 
+local minify = true
+local minifyFilters = {
+ {"%-%-%[%[.-%]%]",""},
+ {"%-%-.-\n","\n"},
+ {"\n[ \t]+","\n"},
+ {"%s?%.%.%s?",".."},
+ {"%s?==%s?","=="},
+ {"%s?~=%s?","~="},
+ {"%s?>=%s?",">="},
+ {"%s?<=%s?","<="},
+ {"%s?>%s?",">"},
+ {"%s?<%s?","<"},
+ {"%s?=%s?","="},
+ {"%s?,%s?",","},
+ {",\n",","},
+ {"\n\n+","\n"},
+ {"[ \t]\n","\n"},
+ {"%{%s+","{"},
+ {"%s+%}","}"}
+}
+
 return setmetatable(preproc,{__call=function(_,...)
  local tA = {...}
  local out = table.remove(tA,#tA)
  local f,e = io.open(out,"wb")
  if not f then error("unable to open file "..out..": "..e) end
- f:write(preproc.preproc(table.unpack(tA)))
+ local out = preproc.preproc(table.unpack(tA))
+ if preproc.minify then
+  local olen = #out
+  for k,v in ipairs(minifyFilters) do
+   out = out:gsub(v[1],v[2])
+  end
+  print(olen, #out)
+ end
+ f:write(out)
  f:close()
 end})