From 06e7149573cc310254b691b3944eeb5d99619ff8 Mon Sep 17 00:00:00 2001
From: payonel <payonel@hotmail.com>
Date: Wed, 26 Oct 2016 22:16:25 -0700
Subject: [PATCH] greatly simplify readnum by leveraging tonumber

---
 .../openos/lib/tools/advanced-buffering.lua   | 140 +++++-------------
 1 file changed, 35 insertions(+), 105 deletions(-)

diff --git a/src/main/resources/assets/opencomputers/loot/openos/lib/tools/advanced-buffering.lua b/src/main/resources/assets/opencomputers/loot/openos/lib/tools/advanced-buffering.lua
index 405a5158a..b2753784c 100644
--- a/src/main/resources/assets/opencomputers/loot/openos/lib/tools/advanced-buffering.lua
+++ b/src/main/resources/assets/opencomputers/loot/openos/lib/tools/advanced-buffering.lua
@@ -12,120 +12,50 @@ function adv_buf.readNumber(self, readChunk)
     len = unicode.len
     sub = unicode.sub
   end
+
   local buffer = ""
-  local first = true
-  local decimal = false
-  local last = false
-  local hex = false
-  local pat = "^[0-9]+"
-  local minbuf = 3 -- "+0x" (sign + hexadecimal tag)
-  -- this function is used to read trailing numbers (1e2, 0x1p2, etc)
-  local function readnum(checksign)
-    local _buffer = ""
-    local sign = ""
-    while true do
-      if len(self.bufferRead) == 0 then
-        local result, reason = readChunk()
-        if not result then
-          if reason then
-            return nil, reason
-          else -- eof
-            return #_buffer > 0 and (sign .. _buffer) or nil
-          end
-        end
-      end
-      if checksign then
-        local _sign = sub(self.bufferRead, 1, 1)
-        if _sign == "+" or _sign == "-" then
-          -- "eat" the sign (Rio Lua behaviour)
-          sign = sub(self.bufferRead, 1, 1)
-          self.bufferRead = sub(self.bufferRead, 2)
-        end
-        checksign = false
-      else
-        local x,y = string.find(self.bufferRead, pat)
-        if not x then
-          break
-        else
-          _buffer = _buffer .. sub(self.bufferRead, 1, y)
-          self.bufferRead = sub(self.bufferRead, y + 1)
-        end
-      end
-    end
-    return #_buffer > 0 and (sign .. _buffer) or nil
-  end
-  while true do
-    if len(self.bufferRead) == 0 or len(self.bufferRead) < minbuf then
+  local white_done
+
+  local function peek()
+    if len(self.bufferRead) == 0 then
       local result, reason = readChunk()
       if not result then
-        if reason then
-          return nil, reason
-        else -- eof
-          return #buffer > 0 and tonumber(buffer) or nil
-        end
+        return result, reason
       end
     end
-    -- these ifs are here so we run the buffer check above
-    if first then
-      local sign = sub(self.bufferRead, 1, 1)
-      if sign == "+" or sign == "-" then
-        -- "eat" the sign (Rio Lua behaviour)
-        buffer = buffer .. sub(self.bufferRead, 1, 1)
-        self.bufferRead = sub(self.bufferRead, 2)
-      end
-      local hextag = sub(self.bufferRead, 1, 2)
-      if hextag == "0x" or hextag == "0X" then
-        pat = "^[0-9A-Fa-f]+"
-        -- "eat" the 0x, see https://gist.github.com/SoniEx2/570a363d81b743353151
-        buffer = buffer .. sub(self.bufferRead, 1, 2)
-        self.bufferRead = sub(self.bufferRead, 3)
-        hex = true
-      end
-      minbuf = 0
-      first = false
-    elseif decimal then
-      local sep = sub(self.bufferRead, 1, 1)
-      if sep == "." then
-        buffer = buffer .. sep
-        self.bufferRead = sub(self.bufferRead, 2)
-        local temp = readnum(false) -- no sign
-        if temp then
-          buffer = buffer .. temp
-        end
-      end
-      if not tonumber(buffer) then break end
-      decimal = false
-      last = true
-      minbuf = 1
-    elseif last then
-      local tag = sub(self.bufferRead, 1, 1)
-      if hex and (tag == "p" or tag == "P") then
-        local temp = sub(self.bufferRead, 1, 1)
-        self.bufferRead = sub(self.bufferRead, 2)
-        local temp2 = readnum(true) -- this eats the next sign if any
-        if temp2 then
-          buffer = buffer .. temp .. temp2
-        end
-      elseif tag == "e" or tag == "E" then
-        local temp = sub(self.bufferRead, 1, 1)
-        self.bufferRead = sub(self.bufferRead, 2)
-        local temp2 = readnum(true) -- this eats the next sign if any
-        if temp2 then
-          buffer = buffer .. temp .. temp2
-        end
-      end
+    return sub(self.bufferRead, 1, 1)
+  end
+
+  local function pop()
+    local n = sub(self.bufferRead, 1, 1)
+    self.bufferRead = sub(self.bufferRead, 2)
+    return n
+  end
+
+  local function take()
+    buffer = buffer .. pop()
+  end
+
+  while true do
+    local peeked = peek()
+    if not peeked then
       break
-    else
-      local x,y = string.find(self.bufferRead, pat)
-      if not x then
-        minbuf = 1
-        decimal = true
-      else
-        buffer = buffer .. sub(self.bufferRead, 1, y)
-        self.bufferRead = sub(self.bufferRead, y + 1)
+    end
+
+    if peeked:match("[%s]") then
+      if white_done then
+        break
       end
+      pop()
+    else
+      white_done = true
+      if not tonumber(buffer .. peeked .. "0") then
+        break
+      end
+      take() -- add pop to buffer
     end
   end
+
   return tonumber(buffer)
 end