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-- mark up comments and strings
STR1 = "\001"
STR2 = "\002"
STR3 = "\003"
STR4 = "\004"
REM = "\005"
ANY = "([\001-\005])"
ESC1 = "\006"
ESC2 = "\007"
MASK = { -- the substitution order is important
{ESC1, "\\'"},
{ESC2, '\\"'},
{STR1, "'"},
{STR2, '"'},
{STR3, "%[%["},
{STR4, "%]%]"},
{REM , "%-%-"},
}
function mask (s)
for i = 1,getn(MASK) do
s = gsub(s,MASK[i][2],MASK[i][1])
end
return s
end
function unmask (s)
for i = 1,getn(MASK) do
s = gsub(s,MASK[i][1],MASK[i][2])
end
return s
end
function clean (s)
-- check for compilation error
local code = "return function () " .. s .. " end"
if not dostring(code) then
return nil
end
local S = "" -- saved string
s = mask(s)
-- remove blanks and comments
while 1 do
local b,e,d = strfind(s,ANY)
if b then
S = S..strsub(s,1,b-1)
s = strsub(s,b+1)
if d==STR1 or d==STR2 then
e = strfind(s,d)
S = S ..d..strsub(s,1,e)
s = strsub(s,e+1)
elseif d==STR3 then
e = strfind(s,STR4)
S = S..d..strsub(s,1,e)
s = strsub(s,e+1)
elseif d==REM then
s = gsub(s,"[^\n]*(\n?)","%1",1)
end
else
S = S..s
break
end
end
-- eliminate unecessary spaces
S = gsub(S,"[ \t]+"," ")
S = gsub(S,"[ \t]*\n[ \t]*","\n")
S = unmask(S)
return S
end
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