| 1 | """AST for ASDL.
|
| 2 |
|
| 3 | This is not self-hosted! If it were, it would look something like this.
|
| 4 |
|
| 5 | (TODO: we should probably improve it! And add static types)
|
| 6 |
|
| 7 | type_ref =
|
| 8 | NamedType(str name, type resolved)
|
| 9 | | ParameterizedType(str type_name, List[type_ref] children)
|
| 10 |
|
| 11 | Field = (type_ref typ, str name)
|
| 12 |
|
| 13 | Constructor = (List[Field] fields, str name, str shared_type)
|
| 14 |
|
| 15 | # TODO: use variant instead of constructor
|
| 16 | variant =
|
| 17 | Simple(str name)
|
| 18 | Compound(str name, List[fields])
|
| 19 | SharedVariant(str tag_name, str shared_variant)
|
| 20 |
|
| 21 | type =
|
| 22 | Sum(List[Constructor] variants, List[str] generate)
|
| 23 | | SimpleSum() # This is just List[name]
|
| 24 | | Product(List[Field] fields)
|
| 25 |
|
| 26 | Use = (List[str] module_parts, str type_names)
|
| 27 | Extern = (List[str] names)
|
| 28 |
|
| 29 | Module = (str name, List[Use] uses, List[Extern] externs, List[binding] defs)
|
| 30 |
|
| 31 | # Note: binding and entry can be combined
|
| 32 |
|
| 33 | binding =
|
| 34 | TypeDecl(str name, type value)
|
| 35 | | SubTypeDecl(str name, type_ref base_class)
|
| 36 |
|
| 37 | entry =
|
| 38 | Use %Use
|
| 39 | | Extern %Extern
|
| 40 | | Binding(binding b)
|
| 41 | """
|
| 42 | from __future__ import print_function
|
| 43 |
|
| 44 | import cStringIO
|
| 45 |
|
| 46 | from typing import List
|
| 47 |
|
| 48 | # The following classes are the AST for the ASDL schema, i.e. the "meta-AST".
|
| 49 | # See the EBNF at the top of the file to understand the logical connection
|
| 50 | # between the various node types.
|
| 51 |
|
| 52 |
|
| 53 | class AST(object):
|
| 54 |
|
| 55 | def Print(self, f, indent):
|
| 56 | raise NotImplementedError()
|
| 57 |
|
| 58 | def __str__(self):
|
| 59 | f = cStringIO.StringIO()
|
| 60 | self.Print(f, 0)
|
| 61 | return f.getvalue()
|
| 62 |
|
| 63 |
|
| 64 | class Use(AST):
|
| 65 |
|
| 66 | def __init__(self, module_parts, type_names):
|
| 67 | self.module_parts = module_parts
|
| 68 | self.type_names = type_names
|
| 69 |
|
| 70 | def Print(self, f, indent):
|
| 71 | ind = indent * ' '
|
| 72 | f.write('%sUse %s {\n' % (ind, ' '.join(self.module_parts)))
|
| 73 | f.write(' %s%s\n' % (ind, ', '.join(t for t in self.type_names)))
|
| 74 | f.write('%s}\n' % ind)
|
| 75 |
|
| 76 |
|
| 77 | class Extern(AST):
|
| 78 |
|
| 79 | def __init__(self, names):
|
| 80 | self.names = names
|
| 81 |
|
| 82 | def Print(self, f, indent):
|
| 83 | ind = indent * ' '
|
| 84 | f.write('%sExtern [ %s ]\n' % (ind, ' '.join(self.names)))
|
| 85 |
|
| 86 |
|
| 87 | class Module(AST):
|
| 88 |
|
| 89 | def __init__(self, name, uses, externs, dfns):
|
| 90 | self.name = name
|
| 91 | self.uses = uses
|
| 92 | self.externs = externs
|
| 93 | self.dfns = dfns
|
| 94 |
|
| 95 | def Print(self, f, indent):
|
| 96 | ind = indent * ' '
|
| 97 | f.write('%sModule %s {\n' % (ind, self.name))
|
| 98 |
|
| 99 | for u in self.uses:
|
| 100 | u.Print(f, indent + 1)
|
| 101 | f.write('\n')
|
| 102 |
|
| 103 | for e in self.externs:
|
| 104 | e.Print(f, indent + 1)
|
| 105 | f.write('\n')
|
| 106 |
|
| 107 | for d in self.dfns:
|
| 108 | d.Print(f, indent + 1)
|
| 109 | f.write('\n')
|
| 110 | f.write('%s}\n' % ind)
|
| 111 |
|
| 112 |
|
| 113 | class TypeDecl(AST):
|
| 114 | """A binding of name to a Sum or Product type."""
|
| 115 |
|
| 116 | def __init__(self, name, value):
|
| 117 | self.name = name # type: str
|
| 118 | self.value = value # type: AST
|
| 119 |
|
| 120 | def Print(self, f, indent):
|
| 121 | ind = indent * ' '
|
| 122 | f.write('%sType %s {\n' % (ind, self.name))
|
| 123 | self.value.Print(f, indent + 1)
|
| 124 | f.write('%s}\n' % ind)
|
| 125 |
|
| 126 |
|
| 127 | class SubTypeDecl(AST):
|
| 128 | """A declaration of a subtype.
|
| 129 |
|
| 130 | CompoundWord < List[word_part]
|
| 131 | """
|
| 132 |
|
| 133 | def __init__(self, name, base_class):
|
| 134 | self.name = name # type: str
|
| 135 | self.base_class = base_class # type: AST
|
| 136 |
|
| 137 | def Print(self, f, indent):
|
| 138 | ind = indent * ' '
|
| 139 | f.write('%sType %s {\n' % (ind, self.name))
|
| 140 | self.base_class.Print(f, indent + 1)
|
| 141 | f.write('%s}\n' % ind)
|
| 142 |
|
| 143 |
|
| 144 | class NamedType(AST):
|
| 145 | """Int, string are resolved to a Primitive type 'Point' can be resolved to
|
| 146 | CompoundSum instance, etc."""
|
| 147 |
|
| 148 | def __init__(self, name):
|
| 149 | # type: (str) -> None
|
| 150 | self.name = name
|
| 151 |
|
| 152 | # Mutated by _ResolveModule / _ResolveType
|
| 153 | self.resolved = None
|
| 154 |
|
| 155 | def Print(self, f, indent):
|
| 156 | """Printed on one line."""
|
| 157 | f.write('NamedType %s' % (self.name)) # printed after field
|
| 158 | f.write(' (%r)' % self.resolved)
|
| 159 |
|
| 160 | def IsOptional(self):
|
| 161 | return False
|
| 162 |
|
| 163 | def IsList(self):
|
| 164 | return False
|
| 165 |
|
| 166 | def IsDict(self):
|
| 167 | return False
|
| 168 |
|
| 169 |
|
| 170 | class ParameterizedType(AST):
|
| 171 | """A parameterized type expression, e.g. the type of a field.
|
| 172 |
|
| 173 | e.g. Dict[string, int] Dict[int, array[string]]
|
| 174 |
|
| 175 | self.children is empty if it's a leaf.
|
| 176 |
|
| 177 | Note:
|
| 178 |
|
| 179 | string* <=> array[string]
|
| 180 | mytype? <=> maybe[mytype]
|
| 181 | """
|
| 182 |
|
| 183 | def __init__(self, type_name, children):
|
| 184 | self.type_name = type_name # type: str
|
| 185 | self.children = children # type: List[AST]
|
| 186 |
|
| 187 | def Print(self, f, indent):
|
| 188 | """Printed on one line."""
|
| 189 | f.write('%s' % (self.type_name)) # printed after field
|
| 190 | if self.children:
|
| 191 | f.write(' [ ')
|
| 192 | for i, child in enumerate(self.children):
|
| 193 | if i != 0:
|
| 194 | f.write(', ')
|
| 195 | child.Print(f, indent + 1)
|
| 196 | f.write(' ]')
|
| 197 |
|
| 198 | def IsOptional(self):
|
| 199 | return self.type_name == 'Optional'
|
| 200 |
|
| 201 | def IsList(self):
|
| 202 | if self.type_name == 'List':
|
| 203 | return True
|
| 204 | if self.type_name == 'Optional':
|
| 205 | return self.children[0].IsList()
|
| 206 | return False
|
| 207 |
|
| 208 | def IsDict(self):
|
| 209 | if self.type_name == 'Dict':
|
| 210 | return True
|
| 211 | if self.type_name == 'Optional':
|
| 212 | return self.children[0].IsDict()
|
| 213 | return False
|
| 214 |
|
| 215 |
|
| 216 | class Field(AST):
|
| 217 |
|
| 218 | def __init__(self, typ, name):
|
| 219 | # type: (AST, str) -> None
|
| 220 | self.typ = typ # type expression
|
| 221 | self.name = name # variable name
|
| 222 |
|
| 223 | def Print(self, f, indent):
|
| 224 | ind = indent * ' '
|
| 225 | f.write('%sField %r ' % (ind, self.name))
|
| 226 | self.typ.Print(f, indent)
|
| 227 | f.write('\n')
|
| 228 |
|
| 229 |
|
| 230 | class _CompoundAST(AST):
|
| 231 | """Either a Product or Constructor.
|
| 232 |
|
| 233 | encode.py and format.py need a reflection API.
|
| 234 | """
|
| 235 |
|
| 236 | def __init__(self, fields):
|
| 237 | self.fields = fields or []
|
| 238 |
|
| 239 |
|
| 240 | class Constructor(_CompoundAST):
|
| 241 |
|
| 242 | def __init__(self, name, shared_type=None, fields=None):
|
| 243 | _CompoundAST.__init__(self, fields)
|
| 244 | self.name = name
|
| 245 | self.shared_type = shared_type # for DoubleQuoted %DoubleQuoted
|
| 246 |
|
| 247 | def Print(self, f, indent):
|
| 248 | ind = indent * ' '
|
| 249 | f.write('%sConstructor %s' % (ind, self.name))
|
| 250 | if self.shared_type:
|
| 251 | f.write(' %%%s' % self.shared_type)
|
| 252 |
|
| 253 | if self.fields:
|
| 254 | f.write(' {\n')
|
| 255 | for field in self.fields:
|
| 256 | field.Print(f, indent + 1)
|
| 257 | f.write('%s}' % ind)
|
| 258 |
|
| 259 | f.write('\n')
|
| 260 |
|
| 261 |
|
| 262 | class Sum(AST):
|
| 263 |
|
| 264 | def __init__(self, types, generate=None):
|
| 265 | self.types = types # type: List[Constructor]
|
| 266 | self.generate = generate or []
|
| 267 |
|
| 268 | def Print(self, f, indent):
|
| 269 | ind = indent * ' '
|
| 270 | f.write('%sSum {\n' % ind)
|
| 271 | for t in self.types:
|
| 272 | t.Print(f, indent + 1)
|
| 273 | if self.generate:
|
| 274 | f.write('%s generate %s\n' % (ind, self.generate))
|
| 275 | f.write('%s}\n' % ind)
|
| 276 |
|
| 277 |
|
| 278 | class SimpleSum(Sum):
|
| 279 | pass
|
| 280 |
|
| 281 |
|
| 282 | class Product(_CompoundAST):
|
| 283 |
|
| 284 | def __init__(self, fields):
|
| 285 | _CompoundAST.__init__(self, fields)
|
| 286 |
|
| 287 | def Print(self, f, indent):
|
| 288 | ind = indent * ' '
|
| 289 | f.write('%sProduct {\n' % ind)
|
| 290 | for field in self.fields:
|
| 291 | field.Print(f, indent + 1)
|
| 292 | f.write('%s}\n' % ind)
|
| 293 |
|
| 294 |
|
| 295 | #
|
| 296 | # Helpers
|
| 297 | #
|
| 298 |
|
| 299 |
|
| 300 | def TypeNameHeuristic(t):
|
| 301 | # type: (str) -> str
|
| 302 | """For 'use'.
|
| 303 |
|
| 304 | We don't parse the imported file, so we have a heuristic based on
|
| 305 | the name! e.g. re_t or BraceGroup
|
| 306 | """
|
| 307 | return '%s_t' % t if t[0].islower() else t
|