Merge pull request geoffleyland#1 from kev82/openstring

Addition of csv.openstring plus other minor fixes

Author: geoffleyland

AUTHORS

@@ -1 +1,2 @@
-Leyland, Geoff
+Leyland, Geoff
+Martin, Kevin

LICENSE

@@ -1,4 +1,5 @@
 Copyright (c) 2013 Incremental IP Limited
+Copyright (c) 2014 Kevin Martin
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -54,6 +54,9 @@ controlling how the file is read:
 + `buffer_size` controls the size of the blocks the file is read in.  The
   default is 4096, which is what `pagesize` says on my system.
 
+`csv.openstring` works exactly like `csv.open` except the first argument
+is the contents of the csv file. In this case `buffer_size` is set to
+the length of the string.
 
 ## 3. Requirements
 

lua/csv.lua

@@ -11,9 +11,10 @@
 --  likely gets something wrong.
 
 --  (c) Copyright 2013 Incremental IP Limited.
+--  (c) Copyright 2014 Kevin Martin
 --  Available under the MIT licence.  See LICENSE for more information.
 
-local DEFAULT_BUFFER_SIZE = 1024
+local DEFAULT_BUFFER_SIZE = 4096
 
 
 ------------------------------------------------------------------------------
@@ -322,6 +323,9 @@ local file_mt =
   close = function(t)
       t.file:close()
     end,
+  name = function(t)
+      return t.parameters.filename
+    end,
 }
 file_mt.__index = file_mt
 
@@ -349,6 +353,52 @@ end
 
 ------------------------------------------------------------------------------
 
-return { open = open, use = use }
+local stringfh_mt =
+{
+  read = function(self, bytes)
+      if not self._string then return nil end
+
+      local read_rv
+      read_rv, self._string =
+       self._string:sub(1, bytes), self._string:sub(bytes+1)
+
+      if #self._string == 0 then
+        self._string = nil
+      end
+
+      return read_rv
+    end,
+  close = function()
+    end
+}
+stringfh_mt.__index = stringfh_mt
+
+--- Open a string for reading as a delimited file
+--  @return a file object
+local function openstring(
+  filecontents,     -- string: The contents of the delimited file
+  parameters)       -- ?table: parameters controlling reading the file.
+                    -- See README.md
+
+  parameters = parameters or {}
+
+  local function makename()
+    local t = {}
+    t[#t+1] = "<(String) "
+    t[#t+1] = (filecontents:gmatch("[^\n]+")() or ""):sub(1,15)
+    if #t[#t] > 14 then t[#t+1] = "..." end
+    t[#t+1] = " >"
+    return table.concat(t)
+  end
+
+  parameters.filename = parameters.filename or makename()
+  parameters.buffer_size = parameters.buffer_size or #filecontents
+  local fileh = setmetatable({_string = filecontents}, stringfh_mt)
+  return use(fileh, parameters)
+end
+
+------------------------------------------------------------------------------
+
+return { open = open, openstring = openstring, use = use }
 
 ------------------------------------------------------------------------------

lua/test.lua

@@ -3,10 +3,9 @@ local csv = require"csv"
 
 local errors = 0
 
-local function test(filename, correct_result, parameters)
+local function testhandle(handle, correct_result)
   local result = {}
-  local f = csv.open(filename, parameters)
-  for r in f:lines() do
+  for r in handle:lines() do
     if not r[1] then
       local r2 = {}
       for k, v in pairs(r) do r2[#r2+1] = k..":"..tostring(v) end
@@ -15,15 +14,33 @@ local function test(filename, correct_result, parameters)
     end
     result[#result+1] = table.concat(r, ",")
   end
+
+  handle:close()
+
   result = table.concat(result, "\n")
   if result ~= correct_result then
     io.stderr:write(
       ("Error reading '%s':\nExpected output:\n%s\n\nActual output:\n%s\n\n"):
-      format(filename, correct_result, result))
+      format(handle:name(), correct_result, result))
     errors = errors + 1
+	return false
   end
+  return true
 end
 
+local function test(filename, correct_result, parameters)
+  local f = csv.open(filename, parameters)
+  local fileok = testhandle(f, correct_result)
+
+  if fileok then
+    f = io.open(filename, "r")
+    local data = f:read("*a")
+    f:close()
+
+    f = csv.openstring(data, parameters)
+    testhandle(f, correct_result)
+  end
+end
 
 test("../test-data/embedded-newlines.csv", [[
 embedded
@@ -62,4 +79,4 @@ else
   io.stdout:write(("%d errors\n"):format(errors))
 end
 
-os.exit(errors)
+os.exit(errors)

test-data/blank-line.csv

@@ -1 +1,2 @@
 this,file,ends,with,a,blank,line
+