4 # Copyright (C) 2011, 2012 Google Inc.
6 # This program is free software; you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation; either version 2 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful, but
12 # WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 # General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program; if not, write to the Free Software
18 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 """Script for converting Python constants to Haskell code fragments.
28 from ganeti import _autoconf
29 from ganeti import compat
30 from ganeti import constants
31 from ganeti import errors
32 from ganeti import luxi
33 from ganeti import qlang
36 #: Constant name regex
37 CONSTANT_RE = re.compile("^[A-Z][A-Z0-9_-]+$")
40 PRIVATE_RE = re.compile("^__.+__$")
42 #: The type of regex objects
43 RE_TYPE = type(CONSTANT_RE)
45 #: Keys which do not declare a value (manually maintained). By adding
46 # values here, we can make more lists use the actual names; otherwise
47 # we'll have (e.g.) both DEFAULT_ENABLED_HYPERVISOR and HT_XEN_PVM
48 # declare the same value, and thus the list of valid hypervisors will
49 # have strings instead of easily looked-up names.
50 IGNORED_DECL_NAMES = ["DEFAULT_ENABLED_HYPERVISOR"]
54 """Converts the upper-cased Python name to Haskell camelCase.
57 name = name.replace("-", "_")
58 elems = name.split("_")
59 return elems[0].lower() + "".join(e.capitalize() for e in elems[1:])
62 def StringValueRules(value):
63 """Converts a string value from Python to Haskell.
66 value = value.encode("string_escape") # escapes backslashes
67 value = value.replace("\"", "\\\"")
71 def DictKeyName(dict_name, key_name):
72 """Converts a dict plus key name to a full name.
75 return"%s_%s" % (dict_name, str(key_name).upper())
78 def HaskellTypeVal(value):
79 """Returns the Haskell type and value for a Python value.
81 Note that this only work for 'plain' Python types.
83 @returns: (string, string) or None, if we can't determine the type.
86 if isinstance(value, basestring):
87 return ("String", "\"%s\"" % StringValueRules(value))
88 elif isinstance(value, int):
89 return ("Int", "%d" % value)
90 elif isinstance(value, long):
91 return ("Integer", "%d" % value)
92 elif isinstance(value, float):
93 return ("Double", "%f" % value)
98 def IdentifyOrigin(all_items, value):
99 """Tries to identify a constant name from a constant's value.
101 This uses a simple algorithm: is there a constant (and only one)
102 with the same value? If so, then it returns that constants' name.
104 @note: it is recommended to use this only for tuples/lists/sets, and
105 not for individual (top-level) values
106 @param all_items: a dictionary of name/values for the current module
107 @param value: the value for which we try to find an origin
110 found = [name for (name, v) in all_items.items()
111 if v is value and name not in IGNORED_DECL_NAMES]
118 def FormatListElems(all_items, pfx_name, ovals, tvals):
119 """Formats a list's elements.
121 This formats the elements as either values or, if we find all
124 @param all_items: a dictionary of name/values for the current module
125 @param pfx_name: the prefix name currently used
126 @param ovals: the list of actual (Python) values
127 @param tvals: the list of values we want to format in the Haskell form
130 origins = [IdentifyOrigin(all_items, v) for v in ovals]
131 if compat.all(x is not None for x in origins):
132 values = [NameRules(pfx_name + origin) for origin in origins]
135 return ", ".join(values)
138 def FormatDict(all_items, pfx_name, py_name, hs_name, mydict):
139 """Converts a dictionary to a Haskell association list ([(k, v)]),
142 @param all_items: a dictionary of name/values for the current module
143 @param pfx_name: the prefix name currently used
144 @param py_name: the Python name
145 @param hs_name: the Haskell name
146 @param mydict: a dictonary, unknown yet if homogenous or not
149 # need this for ordering
150 orig_list = mydict.items()
151 list_form = [(HaskellTypeVal(k), HaskellTypeVal(v)) for k, v in orig_list]
152 if compat.any(v is None or k is None for k, v in list_form):
155 all_keys = [k for k, _ in list_form]
156 all_vals = [v for _, v in list_form]
157 key_types = set(k[0] for k in all_keys)
158 val_types = set(v[0] for v in all_vals)
159 if not(len(key_types) == 1 and len(val_types) == 1):
162 # record the key and value Haskell types
163 key_type = key_types.pop()
164 val_type = val_types.pop()
166 # now try to find names for the keys, instead of raw values
167 key_origins = [IdentifyOrigin(all_items, k) for k, _ in orig_list]
168 if compat.all(x is not None for x in key_origins):
169 key_v = [NameRules(pfx_name + origin) for origin in key_origins]
171 key_v = [k[1] for k in all_keys]
173 val_origins = [IdentifyOrigin(all_items, v) for _, v in orig_list]
174 if compat.all(x is not None for x in val_origins):
175 val_v = [NameRules(pfx_name + origin) for origin in val_origins]
177 val_v = [v[1] for v in all_vals]
179 # finally generate the output
180 kv_pairs = ["(%s, %s)" % (k, v) for k, v in zip(key_v, val_v)]
181 return ["-- | Converted from Python dictionary %s" % py_name,
182 "%s :: [(%s, %s)]" % (hs_name, key_type, val_type),
183 "%s = [%s]" % (hs_name, ", ".join(kv_pairs)),
187 def ConvertVariable(prefix, name, value, all_items):
188 """Converts a given variable to Haskell code.
190 @param prefix: a prefix for the Haskell name (useful for module
192 @param name: the Python name
193 @param value: the value
194 @param all_items: a dictionary of name/value for the module being
196 @return: a list of Haskell code lines
201 pfx_name = prefix + "_"
202 fqn = prefix + "." + name
206 hs_name = NameRules(pfx_name + name)
207 hs_typeval = HaskellTypeVal(value)
208 if (isinstance(value, types.ModuleType) or callable(value) or
209 PRIVATE_RE.match(name)):
210 # no sense in marking these, as we don't _want_ to convert them; the
211 # message in the next if block is for datatypes we don't _know_
212 # (yet) how to convert
214 elif not CONSTANT_RE.match(name):
215 lines.append("-- Skipped %s %s, not constant" % (fqn, type(value)))
216 elif hs_typeval is not None:
217 # this is a simple value
218 (hs_type, hs_val) = hs_typeval
219 lines.append("-- | Converted from Python constant %s" % fqn)
220 lines.append("%s :: %s" % (hs_name, hs_type))
221 lines.append("%s = %s" % (hs_name, hs_val))
222 elif isinstance(value, dict):
224 lines.append("-- Following lines come from dictionary %s" % fqn)
225 # try to build a real map here, if all keys have same type, and
226 # all values too (i.e. we have a homogeneous dictionary)
227 lines.extend(FormatDict(all_items, pfx_name, fqn, hs_name, value))
228 # and now create individual names
229 for k in sorted(value.keys()):
230 lines.extend(ConvertVariable(prefix, DictKeyName(name, k),
231 value[k], all_items))
232 elif isinstance(value, tuple):
233 tvs = [HaskellTypeVal(elem) for elem in value]
234 if compat.all(e is not None for e in tvs):
235 ttypes = ", ".join(e[0] for e in tvs)
236 tvals = FormatListElems(all_items, pfx_name, value, [e[1] for e in tvs])
237 lines.append("-- | Converted from Python tuple %s" % fqn)
238 lines.append("%s :: (%s)" % (hs_name, ttypes))
239 lines.append("%s = (%s)" % (hs_name, tvals))
241 lines.append("-- Skipped tuple %s, cannot convert all elements" % fqn)
242 elif isinstance(value, (list, set, frozenset)):
243 # Lists and frozensets are handled the same in Haskell: as lists,
244 # since lists are immutable and we don't need for constants the
245 # high-speed of an actual Set type. However, we can only convert
246 # them if they have the same type for all elements (which is a
247 # normal expectation for constants, our code should be well
248 # behaved); note that this is different from the tuples case,
249 # where we always (for some values of always) can convert
250 tvs = [HaskellTypeVal(elem) for elem in value]
251 if compat.all(e is not None for e in tvs):
252 ttypes, tvals = zip(*tvs)
253 uniq_types = set(ttypes)
254 if len(uniq_types) == 1:
255 values = FormatListElems(all_items, pfx_name, value, tvals)
256 lines.append("-- | Converted from Python list or set %s" % fqn)
257 lines.append("%s :: [%s]" % (hs_name, uniq_types.pop()))
258 lines.append("%s = [%s]" % (hs_name, values))
260 lines.append("-- | Skipped list/set %s, is not homogeneous" % fqn)
262 lines.append("-- | Skipped list/set %s, cannot convert all elems" % fqn)
263 elif isinstance(value, RE_TYPE):
264 tvs = HaskellTypeVal(value.pattern)
265 assert tvs is not None
266 lines.append("-- | Converted from Python RE object %s" % fqn)
267 lines.append("%s :: %s" % (hs_name, tvs[0]))
268 lines.append("%s = %s" % (hs_name, tvs[1]))
270 lines.append("-- Skipped %s, %s not handled" % (fqn, type(value)))
274 def Convert(module, prefix):
275 """Converts the constants to Haskell.
280 all_items = dict((name, getattr(module, name)) for name in dir(module))
282 for name in sorted(all_items.keys()):
283 value = all_items[name]
284 new_lines = ConvertVariable(prefix, name, value, all_items)
286 lines.extend(new_lines)
289 return "\n".join(lines)
293 print Convert(constants, "")
294 print Convert(luxi, "luxi")
295 print Convert(qlang, "qlang")
296 print Convert(_autoconf, "autoconf")
297 print Convert(errors, "errors")
300 if __name__ == "__main__":