version0.7.10

lib/parsecsv.nim

@@ -1,176 +0,0 @@
-#
-#
-#            Nimrod's Runtime Library
-#        (c) Copyright 2009 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## This module implements a simple high performance `CSV`:idx:
-## (`comma separated value`:idx:) parser. 
-##
-## Example: How to use the parser
-## ==============================
-##
-## .. code-block:: nimrod
-##   import os, parsecsv, streams
-##   var s = newFileStream(ParamStr(1), fmRead)
-##   if s == nil: quit("cannot open the file" & ParamStr(1))
-##   var x: TCsvParser
-##   open(x, s, ParamStr(1))
-##   while readRow(x):
-##     Echo "new row: "
-##     for val in items(x.row):
-##       Echo "##", val, "##"
-##   close(x)
-##
-
-import
-  lexbase, streams
-
-type
-  TCsvRow* = seq[string] ## a row in a CSV file
-  TCsvParser* = object of TBaseLexer ## the parser object.
-    row*: TCsvRow                    ## the current row
-    filename: string
-    sep, quote, esc: char
-    skipWhite: bool
-    currRow: int
-
-  EInvalidCsv* = object of EIO ## exception that is raised if
-                               ## a parsing error occurs
-
-proc raiseEInvalidCsv(filename: string, line, col: int, 
-                      msg: string) {.noreturn.} =
-  var e: ref EInvalidCsv
-  new(e)
-  e.msg = filename & "(" & $line & ", " & $col & ") Error: " & msg
-  raise e
-
-proc error(my: TCsvParser, pos: int, msg: string) = 
-  raiseEInvalidCsv(my.filename, my.LineNumber, getColNumber(my, pos), msg)
-
-proc open*(my: var TCsvParser, input: PStream, filename: string,
-           separator = ',', quote = '"', escape = '\0',
-           skipInitialSpace = false) =
-  ## initializes the parser with an input stream. `Filename` is only used
-  ## for nice error messages. The parser's behaviour can be controlled by
-  ## the diverse optional parameters:
-  ## - `separator`: character used to separate fields
-  ## - `quote`: Used to quote fields containing special characters like 
-  ##   `separator`, `quote` or new-line characters. '\0' disables the parsing
-  ##   of quotes.
-  ## - `escape`: removes any special meaning from the following character; 
-  ##   '\0' disables escaping; if escaping is disabled and `quote` is not '\0',
-  ##   two `quote` characters are parsed one literal `quote` character.
-  ## - `skipInitialSpace`: If true, whitespace immediately following the 
-  ##   `separator` is ignored.
-  lexbase.open(my, input)
-  my.filename = filename
-  my.sep = separator
-  my.quote = quote
-  my.esc = escape
-  my.skipWhite = skipInitialSpace
-  my.row = @[]
-  my.currRow = 0
-
-proc parseField(my: var TCsvParser, a: var string) = 
-  var pos = my.bufpos
-  var buf = my.buf
-  if my.skipWhite:
-    while buf[pos] in {' ', '\t'}: inc(pos)
-  setLen(a, 0) # reuse memory
-  if buf[pos] == my.quote and my.quote != '\0': 
-    inc(pos)
-    while true: 
-      var c = buf[pos]
-      if c == '\0':
-        my.bufpos = pos # can continue after exception?
-        error(my, pos, my.quote & " expected")
-        break
-      elif c == my.quote: 
-        if my.esc == '\0' and buf[pos+1] == my.quote:
-          add(a, my.quote)
-          inc(pos, 2)
-        else:
-          inc(pos)
-          break
-      elif c == my.esc:
-        add(a, buf[pos+1])
-        inc(pos, 2)
-      else:
-        case c
-        of '\c': 
-          pos = handleCR(my, pos)
-          add(a, "\n")
-        of '\l': 
-          pos = handleLF(my, pos)
-          add(a, "\n")
-        else:
-          add(a, c)
-          inc(pos)
-  else:
-    while true:
-      var c = buf[pos]
-      if c == my.sep: break
-      if c in {'\c', '\l', '\0'}: break
-      add(a, c)
-      inc(pos)
-  my.bufpos = pos
-
-proc processedRows*(my: var TCsvParser): int = 
-  ## returns number of the processed rows
-  return my.currRow
-
-proc readRow*(my: var TCsvParser, columns = 0): bool = 
-  ## reads the next row; if `columns` > 0, it expects the row to have
-  ## exactly this many columns. Returns false if the end of the file
-  ## has been encountered else true.
-  var col = 0 # current column
-  var oldpos = my.bufpos
-  while my.buf[my.bufpos] != '\0':
-    var oldlen = my.row.len
-    if oldlen < col+1:
-      setLen(my.row, col+1)
-      my.row[col] = ""
-    parseField(my, my.row[col])
-    inc(col)
-    if my.buf[my.bufpos] == my.sep: 
-      inc(my.bufpos)
-    else:
-      case my.buf[my.bufpos]
-      of '\c', '\l': 
-        # skip empty lines:
-        while true: 
-          case my.buf[my.bufpos]
-          of '\c': my.bufpos = handleCR(my, my.bufpos)
-          of '\l': my.bufpos = handleLF(my, my.bufpos)
-          else: break
-      of '\0': nil
-      else: error(my, my.bufpos, my.sep & " expected")
-      break
-  
-  setlen(my.row, col)
-  result = col > 0
-  if result and col != columns and columns > 0: 
-    error(my, oldpos+1, $columns & " columns expected, but found " & 
-          $col & " columns")
-  inc(my.currRow)
-  
-proc close*(my: var TCsvParser) {.inline.} = 
-  ## closes the parser `my` and its associated input stream.
-  lexbase.close(my)
-
-when isMainModule:
-  import os
-  var s = newFileStream(ParamStr(1), fmRead)
-  if s == nil: quit("cannot open the file" & ParamStr(1))
-  var x: TCsvParser
-  open(x, s, ParamStr(1))
-  while readRow(x):
-    Echo "new row: "
-    for val in items(x.row):
-      Echo "##", val, "##"
-  close(x)
-