def __init__(self, str, precedence = None):
self.operator = str
if not precedences.has_key(str):
raise CalcException("unknown operator %s" % str)
if not precedence:
precedence = precedences[self.operator]
self.precedence = precedence
def getBaseUnit(str):
if prefixes.has_key(str):
return prefixes[str]
elif units.has_key(str):
return units[str]
else:
raise CalcException("unknown unit %s" % str)
def convertToCompatibleUnits(self, other):
if self.units == other.units:
return other
recip = other.reciprocal()
if recip and self.units == recip.units:
return recip
if self.makeBaseUnits() or other.makeBaseUnits():
return self.convertToCompatibleUnits(other)
raise CalcException("incompatible units in %s and %s" % (self, other))
def parseToken(self, t):
debugPrint("parsing %s" % t)
if (t == "in") or (t == "to"):
self.parsingConversion = True
if len(t) < 1:
return False
for r in self.regexes:
if r.match(t):
value = self.regexes[r](t)
self.processValue(value)
return True
raise CalcException("unknown token %s" % t)
return False
def pow(self, op, other):
if other.units:
raise CalcException(
"exponent is not allowed to have units in (%s)^%s" %
(self, other))
a = self.value
b = other.value
n = Number(a**b, self.isConversion)
for unit in self.units:
count = self.units[unit]
count *= b
if abs(count - round(count)) > 0.000001:
n.units = self.units
n.value = self.value
n.makeBaseUnits()
n.value = n.value**other.value
if n.units:
raise CalcException("exponent/unit mismatch in (%s)^%s" %
(self, other))
break
n.addUnitCount(unit, int(round(count)))
return n
def eval(self, op, other):
n = None
funcs = {
'+': self.addSub,
'-': self.addSub,
'*': self.divMul,
'/': self.divMul,
'^': self.pow,
'in': self.convert,
'to': self.convert
}
if funcs.has_key(op):
return funcs[op](op, other)
else:
raise CalcException("unimplemented operator %s" % op)
def get(str):
if units.has_key(str):
return units[str]
else:
raise CalcException("unknown unit %s" % str)
substr = str[:l]
if l < len(str) and prefixes.has_key(substr):
unit = prefixes[substr]
elif units.has_key(substr):
unit = units[substr]
elif constants.has_key(substr):
unit = constants[substr]
if unit != None:
if l == len(str):
return [unit]
else:
try:
return [unit] + parseUnits(str[l:])
except CalcException, inst:
pass
raise CalcException("unknown unit %s" % str)
def getBaseUnit(str):
if prefixes.has_key(str):
return prefixes[str]
elif units.has_key(str):
return units[str]
else:
raise CalcException("unknown unit %s" % str)
baseUnits = [
Unit('m', 'meter'),
Unit('g', 'gram'),
Unit('s', 'second'),