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"""Generate ast module from specification"""
import fileinput
import getopt
import re
import sys
from StringIO import StringIO
SPEC = "ast.txt"
COMMA = ", "
def load_boilerplate(file):
f = open(file)
buf = f.read()
f.close()
i = buf.find('### ''PROLOGUE')
j = buf.find('### ''EPILOGUE')
pro = buf[i+12:j].strip()
epi = buf[j+12:].strip()
return pro, epi
def strip_default(arg):
"""Return the argname from an 'arg = default' string"""
i = arg.find('=')
if i == -1:
return arg
return arg[:i].strip()
class NodeInfo:
"""Each instance describes a specific AST node"""
def __init__(self, name, args):
self.name = name
self.args = args.strip()
self.argnames = self.get_argnames()
self.nargs = len(self.argnames)
self.children = COMMA.join(["self.%s" % c
for c in self.argnames])
self.init = []
def get_argnames(self):
if '(' in self.args:
i = self.args.find('(')
j = self.args.rfind(')')
args = self.args[i+1:j]
else:
args = self.args
return [strip_default(arg.strip())
for arg in args.split(',') if arg]
def gen_source(self):
buf = StringIO()
print >> buf, "class %s(Node):" % self.name
print >> buf, ' nodes["%s"] = "%s"' % (self.name.lower(), self.name)
self._gen_init(buf)
self._gen_getChildren(buf)
self._gen_repr(buf)
buf.seek(0, 0)
return buf.read()
def _gen_init(self, buf):
print >> buf, " def __init__(self, %s):" % self.args
if self.argnames:
for name in self.argnames:
print >> buf, " self.%s = %s" % (name, name)
else:
print >> buf, " pass"
if self.init:
print >> buf, "".join([" " + line for line in self.init])
def _gen_getChildren(self, buf):
print >> buf, " def _getChildren(self):"
if self.argnames:
if self.nargs == 1:
print >> buf, " return %s," % self.children
else:
print >> buf, " return %s" % self.children
else:
print >> buf, " return ()"
def _gen_repr(self, buf):
print >> buf, " def __repr__(self):"
if self.argnames:
fmt = COMMA.join(["%s"] * self.nargs)
if '(' in self.args:
fmt = '(%s)' % fmt
vals = ["repr(self.%s)" % name for name in self.argnames]
vals = COMMA.join(vals)
if self.nargs == 1:
vals = vals + ","
print >> buf, ' return "%s(%s)" %% (%s)' % \
(self.name, fmt, vals)
else:
print >> buf, ' return "%s()"' % self.name
rx_init = re.compile('init\((.*)\):')
def parse_spec(file):
classes = {}
cur = None
for line in fileinput.input(file):
mo = rx_init.search(line)
if mo is None:
if cur is None:
# a normal entry
try:
name, args = line.split(':')
except ValueError:
continue
classes[name] = NodeInfo(name, args)
cur = None
else:
# some code for the __init__ method
cur.init.append(line)
else:
# some extra code for a Node's __init__ method
name = mo.group(1)
cur = classes[name]
return classes.values()
def main():
prologue, epilogue = load_boilerplate(sys.argv[-1])
print prologue
print
classes = parse_spec(SPEC)
for info in classes:
print info.gen_source()
print epilogue
if __name__ == "__main__":
main()
sys.exit(0)
### PROLOGUE
"""Python abstract syntax node definitions
This file is automatically generated.
"""
from types import TupleType, ListType
from consts import CO_VARARGS, CO_VARKEYWORDS
def flatten(list):
l = []
for elt in list:
t = type(elt)
if t is TupleType or t is ListType:
for elt2 in flatten(elt):
l.append(elt2)
else:
l.append(elt)
return l
def asList(nodes):
l = []
for item in nodes:
if hasattr(item, "asList"):
l.append(item.asList())
else:
t = type(item)
if t is TupleType or t is ListType:
l.append(tuple(asList(item)))
else:
l.append(item)
return l
nodes = {}
class Node:
lineno = None
def getType(self):
pass
def getChildren(self):
# XXX It would be better to generate flat values to begin with
return flatten(self._getChildren())
def asList(self):
return tuple(asList(self.getChildren()))
def getChildNodes(self):
return [n for n in self.getChildren() if isinstance(n, Node)]
class EmptyNode(Node):
def __init__(self):
self.lineno = None
### EPILOGUE
klasses = globals()
for k in nodes.keys():
nodes[k] = klasses[nodes[k]]
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