lstring.lua

local DBG = function()end
-- other locales are NOT supported
local function list_iter(tab,i,...)
   if i==nil then i=0 end
   local v=tab[i+1]
   if v==nil then return v end
   return i+1,v
end
local pairs_iter = next -- no way (as far as I know) to do this in lua
-- !(
-- local err_enabled = false
-- local eval = evaluate
-- local function errorm(n)
--    if err_enabled then
--       return "error("..n..")"
--    else
--       return ""
--    end   
-- end
-- local function typecheck(var,pos,name,typ)
--    if not err_enabled then return "" end
--    typ=eval(typ)
--    if type(typ)=="string" then
--       return "if type("..var..")~="..toLua(typ).." then "..errorm("\"bad argument #"..eval(pos).." to '"..eval(name).."' ("..typ.." expected, got \"..("..var.."==nil and \"no value\" or type(var))..\")\"").." end"
--    elseif type(typ)=="table" then
--       outputLua("if ")
--       for i,v in next, typ do
--          if i~=1 then
--             outputLua("and ")
--          end
--          outputLua("type("..var..")~="..toLua(v).." ")
--       end
--       outputLua("then ")
--       outputLua(errorm("\"bad argument #"..pos.." to '"..eval(name).."' ("..typ[1].." expected, got \"..("..var.."==nil and \"no value\" or type("..var.."))..\")\""))
--       outputLua(" end")
--    end
-- end
-- --print(typecheck('ab',1,'nonexist','{"number","string"}'))
-- )

local function typecast(var,type_)
   local vartype = type(var)
   if vartype==type_ then return true,var end
   if vartype=="string" then
      if type_=="number" then
         local new = tonumber(var)
         if new then
            return true, new
         else
            return false, nil
         end
      end
   elseif vartype=="number" then
      if type_=="string" then
         return true, tostring(var)
      end
   end
   return false, nil
end
local function typecheck(var,pos,name,typ)
   if type(typ)=="string" then
      if type(var)~=typ then
         error("bad argument #"..pos.." to '"..name.."' ("..typ.." expected, got "..(var==nil and "no value" or type(var))..")",3)
      end
   elseif type(typ)=="table" then
      local mat = false
      for _,v in next,typ do
         if type(var)==v then mat=true;break end
      end
      if not mat then
         error("bad argument #"..pos.." to '"..name.."' ("..typ[1].." expected, got "..(var==nil and "no value" or type(var))..")",3)
      end
   end
end
local function typecheckv(name,types,...)
   local can_cast = types.implicit_casting
   local nargs,args = select('#',...),{...}
   local ret = {}
   for i,v in next,types do
      if type(i)=="number" then
         local val = args[i]
         local type_ = type(val)
         local is_none = i>nargs and val==nil
         local required = not v.optional
         if v.custom then
            local success,reason = v[1](val,type_,is_none,(can_cast and typecast) or nil)
            if required and success==nil then
               error('bad argument #'..i.." to '"..name.."'"..(reason~=nil and " ("..reason..")" or ""),3)
            end
            if success~=nil then
               val=success
            end
         else
            local matched,bad_typecast = false,false
            if not is_none then
               for ti,b in next,v do
                  --print('awlcast',typecast(val,b))
                  if type(ti)=="number" and (type_==b or can_cast) then
                  	  if can_cast then
                  	     local s,r = typecast(val,b)
                  	     --print('cast',s,r)
                  	     val=r
                  	     if not s then
                  	        bad_typecast=true;break
                  	     end
                  	  end
                  	  matched=true;break
                  end
               end
            end
            --print(matched,required,bad_typecast)
            if not matched then
               if required or bad_typecast then
                  error("bad argument #"..i.." to '"..name.."' ("..v[1].." expected, got "..(is_none and 'no value' or type_)..")",3)
               elseif v.default and is_none then
                  val=v.default
               end
            end
         end
         ret[i]=val
      end
   end
   return unpack(ret)
end


local function unimpl(s)
   return (function()
      error("'"..s.."' is unimplemented",2)
   end)
end
local function find(a,b)
   for i,v in pairs_iter,a do
      if v==b then return i end
   end
   return nil
end
local byte_lookup = {[0]="\0";[1]="\1";[2]="\2";[3]="\3";[4]="\4";[5]="\5";[6]="\6";[7]="\b";[8]="\8";[9]="\t";[10]="\10";[11]="\11";[12]="\n";[13]="\13";[14]="\14";[15]="\r";[16]="\16";[17]="\17";[18]="\18";[19]="\19";[20]="\20";[21]="\21";[22]="\22";[23]="\23";[24]="\24";[25]="\25";[26]="\26";[27]="\27";[28]="\28";[29]="\29";[30]="\30";[31]="\31";[32]=" ";[33]="!";[34]="\"";[35]="#";[36]="$";[37]="%";[38]="&";[39]="'";[40]="(";[41]=")";[42]="*";[43]="+";[44]=",";[45]="-";[46]=".";[47]="/";[48]="0";[49]="1";[50]="2";[51]="3";[52]="4";[53]="5";[54]="6";[55]="7";[56]="8";[57]="9";[58]=":";[59]=";";[60]="<";[61]="=";[62]=">";[63]="?";[64]="@";[65]="A";[66]="B";[67]="C";[68]="D";[69]="E";[70]="F";[71]="G";[72]="H";[73]="I";[74]="J";[75]="K";[76]="L";[77]="M";[78]="N";[79]="O";[80]="P";[81]="Q";[82]="R";[83]="S";[84]="T";[85]="U";[86]="V";[87]="W";[88]="X";[89]="Y";[90]="Z";[91]="[";[92]="\\";[93]="]";[94]="^";[95]="_";[96]="`";[97]="a";[98]="b";[99]="c";[100]="d";[101]="e";[102]="f";[103]="g";[104]="h";[105]="i";[106]="j";[107]="k";[108]="l";[109]="m";[110]="n";[111]="o";[112]="p";[113]="q";[114]="r";[115]="s";[116]="t";[117]="u";[118]="v";[119]="w";[120]="x";[121]="y";[122]="z";[123]="{";[124]="|";[125]="}";[126]="~";[127]="\127";[128]="\128";[129]="\129";[130]="\130";[131]="\131";[132]="\132";[133]="\133";[134]="\\";[135]="\135";[136]="\136";[137]="\137";[138]="\138";[139]="\139";[140]="\140";[141]="\141";[142]="\142";[143]="\143";[144]="\144";[145]="\145";[146]="\146";[147]="\147";[148]="\148";[149]="\149";[150]="\150";[151]="\151";[152]="\152";[153]="\153";[154]="\154";[155]="\155";[156]="\156";[157]="\157";[158]="\158";[159]="\159";[160]="\160";[161]="\161";[162]="\162";[163]="\163";[164]="\164";[165]="\165";[166]="\166";[167]="\167";[168]="\168";[169]="\169";[170]="\170";[171]="\171";[172]="\172";[173]="\173";[174]="\174";[175]="\175";[176]="\176";[177]="\177";[178]="\178";[179]="\179";[180]="\180";[181]="\181";[182]="\182";[183]="\183";[184]="\184";[185]="\185";[186]="\186";[187]="\187";[188]="\188";[189]="\189";[190]="\190";[191]="\191";[192]="\192";[193]="\193";[194]="\194";[195]="\195";[196]="\196";[197]="\197";[198]="\198";[199]="\199";[200]="\200";[201]="\201";[202]="\202";[203]="\203";[204]="\204";[205]="\205";[206]="\206";[207]="\207";[208]="\208";[209]="\209";[210]="\210";[211]="\211";[212]="\212";[213]="\213";[214]="\214";[215]="\215";[216]="\216";[217]="\217";[218]="\218";[219]="\219";[220]="\220";[221]="\221";[222]="\222";[223]="\223";[224]="\224";[225]="\225";[226]="\226";[227]="\227";[228]="\228";[229]="\229";[230]="\230";[231]="\231";[232]="\232";[233]="\233";[234]="\234";[235]="\235";[236]="\236";[237]="\237";[238]="\238";[239]="\239";[240]="\240";[241]="\241";[242]="\242";[243]="\243";[244]="\244";[245]="\245";[246]="\246";[247]="\247";[248]="\248";[249]="\249";[250]="\250";[251]="\251";[252]="\252";[253]="\253";[254]="\254";[255]="\255";}
local upper_lookup = {}
for i=97,122 do
   upper_lookup[byte_lookup[i]]=byte_lookup[i-32]
end

local string = {}
string.sub = ("").sub
function string.upper(...)
   local s=typecheckv('upper',{
      implicit_casting=true;
      {'string'};
   },...)
   local n = ""
   for i=1,#s do
      n=n..(upper_lookup[string.sub(s,i,i)] or string.sub(s,i,i))
   end
   return n
end
function string.lower(...)
   local s=typecheckv('lower',{
      implicit_casting=true;
      {"string"}
   },...)
   local n = ""
   for i=1,#s do
      n=n..(find(upper_lookup,string.sub(s,i,i)) or string.sub(s,i,i))
   end
   return n
end
function string.reverse(...)
   local s=typecheckv('reverse',{
      implicit_casting=true;
      {'string'}
   },...)
   local n = ""
   for i=#s,1,-1 do
      n=n..string.sub(s,i,i)
   end
   return n
end
function string.len(...)
   local s=typecheckv('len',{
      implicit_casting=true;
      {'string'}
   },...)
   return #s
end
function string.rep(...)
   local s,a=typecheckv('rep',{
      implicit_casting=true;
      {'string'};
      {'number'};
   },...)
   local n = ""
   for i=1,a do
      n=n..s
   end
   return n
end
function string.char(...)
   local args = {...}
   local n = ""
   for i,v in list_iter,args do
      typecheck(v,i,'char',{'number','string'})
      if type(v)=="string" then
         local n = tonumber(v)
         if n==nil then
            typecheck(v,1,'char','number')
         end
         v=n
      end
      if i>255 or i<0 then error("bad argument #"..i.." to 'char' (invalid value)") end
      n=n..byte_lookup[v]
   end
   return n
end
function string.byte(...)
   local str,index,amount=typecheckv('byte',{
      implicit_casting=true;
      {'string'};
      {'number',default=1,optional=true};
      {'number',default=1,optional=true};
   },...)
   str=string.sub(str,index,index+amount-1)
   local re = {}
   for i=1,#str do
      re[i]=find(byte_lookup,string.sub(str,i,i))
   end
   return unpack(re)
end
function string.dump(...)
   local f,strip=typecheckv('dump',{
      {'function'};
      {'dump',optional=true,default=false};
   },...)
   error('string.dump is unimplemented')
end
do
   if false then
      local get_cptr = require('./cptr')
      local pattern_classes = {
         ["."]=(function()
            local n = {}
            for i=1,256 do
               n[i+1]=i-1
            end
            return string.char(unpack(n))
         end)();
         ["a"]="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
         ["l"]="abcdefghijklmnopqrstuvwxyz";
         ["u"]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
         ["d"]="0123456789";
         ["p"]="!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~";
         ["w"]="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
         ["s"]=" \v\t\r\n";
         ["c"]="\0\1\2\3\4\5\6\7\8\9\10\11\12\13\14\15\16\17\18\19\20\21\22\23\24\25\26\27\28\29\30\31\127";
         ["x"]="01233456789abcdefABCDEF";
         ["z"]="\0";
      }
      -- translation from lstrlib.c's "PATTERN MATCHING" section
      local CAP_UNFINISHED = -1
      local CAP_POSITION = -2
      local LUA_MAXCAPTURES = 5000
      -- typedef struct MatchState {
      --   const char *src_init;  /* init of source string */
      --   const char *src_end;  /* end (`\0') of source string */
      --   lua_State *L;
      --   int level;  /* total number of captures (finished or unfinished) */
      --   struct {
      --     const char *init;
      --     ptrdiff_t len;
      --   } capture[LUA_MAXCAPTURES];
      -- } MatchState;
      --end
      local L_ESC = "%"
      local SPECIALS="^$*+?.([%-"
      local match
      local function check_capture(ms,l)
         l=l-1
         if l<0 or l>=ms.level or ms.capture[l].len == CAP_UNFINISHED then
            error("invalid capture index")
         end
         return l
      end
      local function capture_to_close(ms)
         for i=1,ms.level do
            if ms.capture[i].len==CAP_UNFINISHED then
               error("invalid pattern capture")
            end
         end
      end
      local function classend(ms,p)
         local p = -p
         local nc = -p+1
         if nc/L_ESC then
            if p*0 then
               error("malformed pattern (ends with %)")
            end
            return -p+1
         elseif nc/"[" then
            if p/"^" then p=p+1 end
            while not p/"]" do
               if p*0 then
                  error("malformed pattern (missing ])")
               end
               if (-p-1)/L_ESC and not p*0 then
                  p=p+1
               end
            end
            return p+1
         else
            return p
         end
      end
      local function islower(c)
         return upper_lookup[c]~=nil
      end
      local function match_class(c,cl)
         local lcl,res = string.lower(cl)
         if     lcl=='a' then res = isalpha(c);
         elseif lcl=='c' then res = iscntrl(c);
         elseif lcl=='d' then res = isdigit(c);
         elseif lcl=='l' then res = islower(c);
         elseif lcl=='p' then res = ispunct(c);
         elseif lcl=='s' then res = isspace(c);
         elseif lcl=='u' then res = isupper(c);
         elseif lcl=='w' then res = isalnum(c);
         elseif lcl=='x' then res = isxdigit(c);
         elseif lcl=='z' then res = (c == 0);
         else
            return (cl/c);
         end
         if islower(cl) then
            return res
         else
            return not res
         end
      end
      local function matchbracketclass(c,p,ce)
         local sig = true
         if (-p+1)/"^" then
            sig = false
         end
         while ((-p+1).p < ec) do
            if (p/L_ESC) then
               p=p+1
               if match_class(c,tostring(p)) then
                  return sig
               end
            elseif (((-p+1)/"-") and ((-p+2).p < ec)) then
               p=p+2
               if -p-2 <= c and c <= p then
                  return sig
               end
            elseif p/c then
               return sig
            end
         end
         return not sig
      end
      local function singlematch(c,p,ep)
         --print("singlematch",c,p,ep)
         if p/"." then
            return 1
         elseif p/L_ESC then
            return match_class(c,-p+1)
         elseif p/"[" then
            return matchbracketclass(c,p,-ep-1)
         else
            return p/tostring(c)
         end
      end
      local function matchbalance(ms,s,p)
         if p*0 or (-p+1)*0 then
            errorm("unbalanced pattern")
         end
         if not s/p then
            return nil
         else
            local b = -p;
            local e = -p+1;
            local cont = 1
            while ((-s+1).p < #ms.src_end) do
               if (s/e) then
                  if (cont-1 == 0) then return s+1 end
               elseif s/b then
                  cont=cont+1
               end
            end
         end
         return nil
      end
      local function max_expand(ms,s,p,ep)
         --print("max_expand",ms,s,p,ep)
         --DBG()
         local i = 1
         while ((-s+i).p < ms.src_end and singlematch(-s+i,p,ep)) do
            i=i+1
         end
         while (i>=0) do
            local res = match(ms,-s-i,-ep)
            if res then return res end
            i=i-1
         end
         return nil
      end
      local function min_expand(ms,s,p,ep)
         --print("min_expand",ms,s,p,ep)
         while true do
            local res = match(ms,s,ep+1)
            if res~=nil then
               return res
            elseif (s.p<ms.src_end and singlematch(s,p,ep)) then
               s=s+1
            else
               return nil
            end
         end
      end
      local function start_capture(ms,s,p,what)
         local level = ms.level;
         if level >= LUA_MAXCAPTURES then
            error("too many captures")
         end
         ms.capture[level].init = s.p
         ms.capture[level].len = what
         ms.level=ms.level+1
         local res=match(ms,s,p)
         if (res==nil) then
            ms.level=ms.level-1
         end
         return res
      end
      local function end_capture(ms,s,p)
         local l = capture_to_close(ms)
         ms.capture[l].len = s-ms.capture[l].init;
         local res = match(ms,s,p)
         if res == nil then
            ms.capture[l].len = CAP_UNFINISHED
         end
         return res
      end
      local function match_capture(ms,s,l)
         l = check_capture(ms,l)
         local len = ms.capture[l].len
         if (ms.src_end-s.p >= len and string.sub(s.s,ms.capture[l].init) == string.sub(s.s,len)) then
            return s+len
         else
            return nil
         end
      end
      function match(ms,s,p)
         local p=-p
         -- print('match',tostring(p),tostring(s))
         if p/"(" then
            if (-p+1)/")" then
               return start_capture(ms,s,-p+2,CAP_POSITION)
            else
               return start_capture(ms,s,-p+1,CAP_UNFINISHED)
            end
         elseif p/")" then
            return end_capture(ms,s,-p+1)
         elseif p==L_ESC then
            local n = -p+1
            if n/"b" then
               s=matchbalance(ms,s,-p+2)
               if s==nil then return s end
               p=p+4
               -- print("submatch-b")
               return match(ms,s,p)
            elseif n/"f" then
               local ep,previous
               p=p+2
               if not p/"[" then
                  error("missing [ after %f in pattern")
               end
               ep = classend(ms,p)
               if s.p==ms.src_init then
                  previous=""
               else
                  previous=tostring(-s-1)
               end
               if matchbracketclass(previous,p,ep-1) or not matchbracketclass(tostring(s),p,ep-1) then
                  return nil
               end
               p=ep
               -- print("submatch-f")
               return match(ms,s,ep)
            else
               if isdigit(tostring(-p+1)) then
                  s=match_capture(ms,s,tostring(-p+1))
                  if s==nil then return nil end
                  p=p+1
                  -- print("submatch-%"..tostring(-p+1))
                  return match(ms,s,p)
               end
               dflt=true
            end
         elseif p*0 then
            return s
         elseif p/"$" then
            if ((-p+1)*0) then
               if s*0 then
                  return s
               else
                  return nil
               end
            else
               dflt=true
            end
         else
            dflt=true
         end
         DBG()
         if dflt then
            -- print("dflt classend param",-p+1)
            local ep = classend(ms,-p+1)
            local m = (s.p<ms.src_end and singlematch(s,p,ep))
            -- print("dflt ep,m",ep,m)
            if ep/"?" then
               local res = match(ms,s+1,ep+1)
               if m and res~=nil then
                  return res
               end
               p=ep+1
               -- print("dflt-submatch-optional")
               return match(ms,s,p)
            elseif ep/"*" then
               return max_expand(ms,s,p,ep)
            elseif ep/"+" then
               if m then
                  return max_expand(ms,s+1,p,ep)
               else
                  return nil
               end
            elseif ep/"-" then
               return min_expand(ms,s,p,ep)
            else
               if not m then
                  return nil
               end
               s=s+1
               p=ep
               -- print("dflt-submatch-fallthrough")
               return match(ms,s,p)
            end
         end
      end
      local function plain_search(l1,l2,init)
         if #l1<#l2 then return false end
         for i=(init or 1),#l1 do
            if string.sub(l1,i,i+#l2-1)==l2 then
               return i
            end
         end
         return false
      end
      local function push_onecapture(ms,i,s,e)
         if s==nil then s=0 end
         if (i>=ms.level) then
            if i==0 then
               return true,s,e-s
            else
               error("invalid capture index ("..i..","..ms.level..")")
            end
         else
            local l = ms.capture[i].len
            if l==CAP_UNFINISHED then
               error("unfinished capture")
            end
            if l==CAP_POSITION then
               return false,ms.capture[i].init-ms.src_init+1
            else
               return true,ms.capture[i].init,l
            end
         end
      end
      local function push_captures(ms,s,e)
         local nlevels = (ms.level==0 and s) and 0 or ms.level
         local n = {}
         for i=0,nlevels do
            local vs={push_onecapture(ms,i,s,e)}
            -- print(i,unpack(vs))
            for si=2,#vs do
               n[#n+1]=vs[si]
            end
         end
         return unpack(n)
      end
      local function string_contains(a,b,init)
         for i=1,#a do
            local c1 = string.sub(a,i,i)
            for si=1,#b do
               if string.sub(b,si,si) == c1 then
                  return true
               end
            end
         end
         return false
      end
      local function str_find_aux(l1,l2,init,raw,find)
         if init==nil or init < 0 then
            init=1
         elseif init>#l1 then
            init=#l1
         end
         local s = get_cptr(l1,1)
         local p = get_cptr(l2,1)
         if (find and (raw or not string_contains(l2,SPECIALS))) then
            local s2 = plain_search(l1,l2,init)
            if s2 then
               return s2-s.p,s2-s.p+#l2-1 -- this part works
            end
         else
            local ms = {}
            local anchor = p/"^" and p+1
            local s1 = -s+init
            ms.src_init = s.p
            ms.src_end = s.p+#l1
            ms.capture = {}
            while ((s1+1).p < ms.src_end and not anchor) do
               ms.level = 0
               local res = match(ms,s1,p)
               if res~=nil then
                  -- print('foun',find)
                  if (find) then
                     -- print('epc',push_captures(ms,nil,0))
                     return s1.p-s.p+1,res.p-s.p+1 --,push_captures(ms,nil,0)
                  else
                     local va = {push_captures(ms,s1.p,res.p)}
                     -- print('va',unpack(va))
                     return string.sub(l1,unpack(va))
                  end
               end
            end
         end
         return nil
      end
   end
   string.gfind = unimpl('gfind')
   string.gmatch = unimpl('gmatch')
   string.gsub = unimpl('gsub')
   string.find = unimpl('find')
   string.match = unimpl('match')
   string.format = unimpl('format')
   -- function string.find(s,pattern,init,raw)
   --    typecheck(s,1,'find',{"string","number"})
   --    if type(s)=="number" then s=tostring(s) end
   --    typecheck(pattern,2,'find',{"string","number"})
   --    if type(pattern)=="number" then pattern=tostring(pattern) end
   --    typecheck(init,3,'find',{"number","string","nil"})
   --    if type(init)=="string" then
   --       local n = tonumber(init)
   --       if n==nil then typecheck(init,3,'find',"number") end
   --       init=ni
   --    elseif init==nil then
   --       init=1
   --    end
   --    typecheck(raw,4,'find',{"boolean","nil"})
   --    return str_find_aux(s,pattern,init,raw,true)
   -- end
   -- function string.match(s,pattern,init)
   --    typecheck(s,1,'match',{"string","number"})
   --    if type(s)=="number" then s=tostring(s) end
   --    typecheck(pattern,2,'match',"string") -- you BETTER not be passing a number as a pattern
   --    typecheck(init,3,'match',{"number","string","nil"})
   --    if type(init)=="string" then
   --       local n = tonumber(init)
   --       if n==nil then typecheck(init,3,'match',"number") end
   --       init=ni
   --    elseif init==nil then
   --       init=1
   --    end
   --    return str_find_aux(s,pattern,init,nil,false)
   -- end
end
return string