Synnefo » snf-ganeti » ganeti-local

#!/usr/bin/python

#

# Copyright (C) 2011 Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Script for converting Python constants to Haskell code fragments.

"""

import re

from ganeti import constants

CONSTANT_RE = re.compile("^[A-Z][A-Z0-9_-]+$")

def NameRules(name):

  """Converts the upper-cased Python name to Haskell camelCase.

  """

  name = name.replace("-", "_")

  elems = name.split("_")

  return elems[0].lower() + "".join(e.capitalize() for e in elems[1:])

def StringValueRules(value):

  """Converts a string value from Python to Haskell.

  """

  value = value.encode("string_escape") # escapes backslashes

  value = value.replace("\"", "\\\"")

  return value

def DictKeyName(dict_name, key_name):

  """Converts a dict plus key name to a full name.

  """

  return"%s_%s" % (dict_name, str(key_name).upper())

def HaskellTypeVal(value):

  """Returns the Haskell type and value for a Python value.

  Note that this only work for 'plain' Python types.

  @returns: (string, string) or None, if we can't determine the type.

  """

  if isinstance(value, basestring):

    return ("String", "\"%s\"" % StringValueRules(value))

  elif isinstance(value, int):

    return ("Int", "%d" % value)

  elif isinstance(value, long):

    return ("Integer", "%d" % value)

  elif isinstance(value, float):

    return ("Double", "%f" % value)

  else:

    return None

def ConvertVariable(name, value):

  """Converts a given variable to Haskell code.

  @param name: the Python name

  @param value: the value

  @return: a list of Haskell code lines

  """

  lines = []

  hs_name = NameRules(name)

  hs_typeval = HaskellTypeVal(value)

  if not CONSTANT_RE.match(name):

    lines.append("-- Skipped %s, not constant" % name)

  elif hs_typeval is not None:

    # this is a simple value

    (hs_type, hs_val) = hs_typeval

    lines.append("-- | Converted from Python constant %s" % name)

    lines.append("%s :: %s" % (hs_name, hs_type))

    lines.append("%s = %s" % (hs_name, hs_val))

  elif isinstance(value, dict):

    if value:

      lines.append("-- Following lines come from dictionary %s" % name)

      for k in sorted(value.keys()):

        lines.extend(ConvertVariable(DictKeyName(name, k), value[k]))

  else:

    lines.append("-- Skipped %s, %s not handled" % (name, type(value)))

  return lines

def Convert():

  """Converts the constants to Haskell.

  """

  lines = [""]

  all_names = dir(constants)

  for name in all_names:

    value = getattr(constants, name)

    lines.extend(ConvertVariable(name, value))

    lines.append("")

  return "\n".join(lines)

def main():

  print Convert()

if __name__ == "__main__":

  main()