Example class that splits a text file into sentences.

svn path=/trunk/externals/loaders/pdlua/; revision=17050

1 files changed, 230 insertions, 0 deletions

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+--[[ 
+--  ltextfile-drip
+--  Output a text file as a sequence of symbols (sentences)
+--  author Martin Peach 20120913
+--]]
+
+-- Pd class
+
+local LTextFileDrip = pd.Class:new():register("ltextfile-drip")
+local file ourTextFile = nil
+local words = {}
+local wordIndex = 0
+local playbackIndex = 0
+local ourSentence, ourRemainingLine = nil
+local ourLine = nil
+
+function LTextFileDrip:initialize(name, atoms)
+--pd.post("LTextFileDrip:initialize-> name is " .. name);
+--pd.post("number of atoms is ".. #atoms)
+--for i,v in ipairs(atoms) do
+--  pd.post(i .. " = " .. v)
+--end
+  if #atoms > 0 then self:openOurTextFile(atoms[1]) end
+  if ourTextFile == nil then pd.post("LTextFileDrip:initialize: unable to open " .. atoms[1]) end
+  self.inlets = 1
+  self.outlets = 3
+  return true
+end
+
+-- LTextFileDrip:openOurTextFile: open a text file using name as a path
+function LTextFileDrip:openOurTextFile(name)
+  if ourTextFile ~= nil then
+--pd.post("LTextFileDrip:openOurTextFile: closing old file")
+    ourTextFile:close()
+    ourTextFile = nil
+  end
+--pd.post("LTextFileDrip:openOurTextFile ( " .. name .. " )")
+  ourTextFile = io.open(name)
+  if ourTextFile == nil then
+    pd.post("LTextFileDrip:openOurTextFile: Unable to open " .. name)
+  end
+  ourRemainingLine = nil
+end
+
+function LTextFileDrip:rewindOurTextFile()
+--  pd.post("LTextFileDrip:rewind")
+  if ourTextFile == nil then
+    pd.post("LTextFileDrip:rewindOurTextFile: no open file")
+  else
+    ourTextFile:seek("set") --sets the position to the beginning of the file (and returns 0)
+    wordIndex = 0
+    playbackIndex = 0
+  end
+end
+
+-- LTextFileDrip:drip: accumulate a line of words from ourTextFile and output them as symbols, one per bang
+function LTextFileDrip:drip()
+  local ourPunc
+  local repeatCount = 0
+
+  if ourTextFile == nil then
+    pd.post("LTextFileDrip:drip: no open file")
+    return
+  end
+--  if wordIndex == 0 then -- read another line
+  repeat
+    repeatCount = repeatCount + 1
+--pd.post("repeat number " .. repeatCount)
+    if ourRemainingLine == nil then
+--pd.post ("1> ourRemainingLine is nil")
+      ourLine = ourTextFile:read()
+      if ourLine == nil then
+        self:outlet(3, "bang", {}) -- end of file
+        return
+      end
+--pd.post ("1> ourLine is [" .. ourLine .. "] len: " .. ourLine:len())
+    -- strip CR LF
+      s,e = ourLine:find("[\n\r]")
+      if s then
+--pd.post("1> CR or LF  at " .. s)
+        ourLine = ourLine:sub(1,s-1) .. " "
+      else
+        ourLine = ourLine .. " "
+      end    
+    elseif ourRemainingLine:len() == 0 then -- read another line
+--pd.post ("2> ourRemainingLine length 0")
+      ourLine = ourTextFile:read()
+      if ourLine == nil then
+        self:outlet(3, "bang", {}) -- end of file
+        return
+      end
+--pd.post ("2> ourLine is [" .. ourLine .. "] len: " .. ourLine:len())
+      s,e = ourLine:find("[\n\r]")
+      if s then
+--pd.post("2> CR or LF at " .. s)
+        ourLine = ourLine:sub(1,s-1) .. " "
+      else
+        ourLine = ourLine .. " "
+      end
+--pd.post("Not setting ourLine from ourRemainingLine, whose length is precisely " .. ourRemainingLine:len())
+    else
+      cstart,cend = ourRemainingLine:find("[,.;!?:]")
+      if cstart == nil then -- no punctuation in remainingLine, add next line from ourTextFile
+--pd.post("3> Adding a new line to ourRemainingLine")
+        ourLine = ourTextFile:read()
+        if ourLine == nil then -- no more lines
+          self:outlet(3, "bang", {}) -- end of file
+          return
+        end
+--pd.post ("3> ourLine is [" .. ourLine .. "] len: " .. ourLine:len())
+        s,e = ourLine:find("[\n\r]")
+        if s then
+--pd.post("3> CR or LF at " .. s)
+          ourLine = ourLine:sub(1,s-1) .. " "
+        else
+          ourLine = ourLine .. " "
+        end
+        --ourLine = ourLine:gsub("[\n\r]", " ")
+        if (ourLine:len() == 1) then -- an empty line
+--pd.post("BLANK LINE (1)")
+          ourLine = "." -- replace blank line with punctuation to force a chop
+        end
+        ourLine = ourRemainingLine .. ourLine
+      else -- remainingLine has punctuation
+--pd.post("4> ourRemainingLine contains punctuation")
+        ourLine = ourRemainingLine
+      end
+      ourRemainingLine = nil
+    end -- if ourRemainingLine == nil
+    ourPunc = nil
+    if ourLine ~= nil then -- line has content
+      if ourLine:len() > 0 then
+        wordIndex = 0
+--pd.post("LTextFileDrip:drip: <" .. ourLine .. ">")
+--pd.post("LTextFileDrip:drip: len" .. ourLine:len())
+--pd.post("LTextFileDrip:drip: 1st char" .. ourLine:byte(1))
+        if ((ourLine:len() == 1) and (ourLine:byte(1) == 13)) then -- a blank line
+--pd.post("BLANK LINE (2)")
+          ourSentence = ourRemainingLine
+          ourRemainingLine = nil
+        else -- find a comma, period, semicolon, exclamation or question mark
+          cstart,cend = ourLine:find("[,.;!?:]")
+          if cstart ~= nil then -- take the line before the mark
+--pd.post("LTextFileDrip:drip: cstart " .. string.format ('%d', cstart) .. " cend " .. string.format('%d', cend))
+            ourPunc = ourLine:sub(cend, cend)
+--pd.post("LTextFileDrip:drip: punctuation: " .. ourPunc)
+            ourSentence = ourLine:sub(1, cend) -- leave punctuation
+            if ourRemainingLine ~= nil then        
+              ourSentence = ourRemainingLine .. ourSentence
+            end
+            ourRemainingLine = ourLine:sub(cend+1)
+--pd.post("LTextFileDrip:drip punctuation found: ourSentence is " .. ourSentence)
+--pd.post("LTextFileDrip:drip punctuation found: ourRemainingLine is " .. ourRemainingLine)
+          else -- no mark, take the whole line
+            if ourRemainingLine ~= nil then         
+              ourRemainingLine = ourRemainingLine .. ourLine
+--pd.post("LTextFileDrip:drip more to come: ourRemainingLine is " .. ourRemainingLine)
+--for c = 1, ourRemainingLine:len() do pd.post("_" .. ourRemainingLine:byte(c) .. "_") end
+            else
+              ourRemainingLine = ourLine
+--pd.post("LTextFileDrip:drip first: ourRemainingLine is " .. ourRemainingLine)
+            end
+          end -- if cstart ~= nil
+        end -- if ((ourLine:len() == 1) and (ourLine:byte(1) == 13))
+      end -- if ourLine:len() > 0
+      if ourSentence ~= nil then
+        if ourSentence:gmatch("%w+") then
+          if ((ourSentence:len() == 1) and (ourSentence:byte(1) <= 32)) then
+--pd.post("BLANK LINE (3)")
+            wordIndex = 0 -- skip blank line
+          else
+           wordIndex = 1
+          end
+--        for w in ourSentence:gmatch("%w+") do
+--          wordIndex = wordIndex + 1
+--          words[wordIndex] = w
+--pd.post("wordIndex " .. wordIndex .. " for length " .. ourSentence:len() .. " starts with " .. ourSentence:byte(1))
+        end
+      end
+      playbackIndex = 1
+    else -- bang through outlet 3 serves as end of file notification
+      self:outlet(3, "bang", {})
+    end -- if ourLine ~= nil
+--  end
+  until ((wordIndex ~= 0) or (ourLine == nil))
+  if ourPunc ~= nil then
+    self:outlet(2, "symbol", {ourPunc}) -- output punctuation
+  end
+  if wordIndex > 0 then -- output sentence as a single symbol
+    if ourSentence ~= nil then
+      len = ourSentence:len()
+--pd.post ("ourSentence:len() is " .. len)
+      if len > 0 then
+--pd.post("ourSentence is not zero-length")
+--pd.post("ourSentence [" .. ourSentence .. "]")
+--pd.post("starts with " .. ourSentence:byte(1))
+        self:outlet(1, "symbol", {ourSentence}) -- output entire line
+      else
+--pd.post("ourSentence is zero-length")
+        self:outlet(1, "bang", {}) -- an empty line
+      end
+    end
+    wordIndex = 0 -- no more words
+    ourSentence = nil -- no more sentence
+  end
+end
+
+function LTextFileDrip:in_1(sel, atoms) -- anything
+--  pd.post("LTextFileDrip:in-> sel is " .. sel);
+--  pd.post("number of atoms is ".. #atoms)
+--  for i,v in ipairs(atoms) do
+--    pd.post(i .. " = " .. v)
+--  end
+  
+  if sel == "bang" then -- output the next sentence
+    self:drip()
+  elseif sel == "open" then -- open a file
+    self:openOurTextFile(atoms[1])    
+  elseif sel == "rewind" then -- rewind the file
+    self:rewindOurTextFile()    
+  elseif sel == "symbol" then -- assume it's a file name
+    self:openOurTextFile(atoms[1])
+  elseif #atoms == 0 then -- a selector
+    self:error("LTextFileDrip:in_1: input not known")
+  else -- reject non-symbols
+    self:error("LTextFileDrip:in_1: input not a symbol or bang")
+  end
+end
+-- end of ltextfile-drip
+