def chkParams(lst,buff):
if lst.kind == -4:
return lst
if lst.getString() == 'NIL':
return 'T'
obj = car(lst)
if(obj.getString() not in buff and not isPrimitive(obj.getString())):
buff.append(obj.getString())
return chkParams(cdr(lst), buff)
else:
return -4
def evaluate(exp, alst,dLst):
if(exp.kind==-4):
return exp
if atom(exp) == 'T':
if isInt(exp) == 'T':
return exp
elif eq(exp,dLst['T']) == 'T':
return dLst['T']
elif eq(exp,dLst['NIL']) == 'T':
return dLst['NIL']
elif getMapping(exp.getString(),alst,False).kind!=-4:
return getMapping(exp.getString(),alst,True)
else:
errorObj = SExp.SExp(-4)
errorObj.string = 'Unbound Variable'
return errorObj
elif atom(car(exp))=='T':
if eq(car(exp),dLst['QUOTE']) == 'T':
if cdr(exp).right.getString() == 'NIL':
return car(cdr(exp))
else:
errorObj = SExp.SExp(-4)
errorObj.string = 'Too Many Args for QUOTE'
return errorObj
elif eq(car(exp),dLst['COND']) == 'T':
return evconHelper(cdr(exp),alst,dLst)
elif eq(car(exp),dLst['DEFUN']) == 'T':
key = car(cdr(exp))
if cdr(cdr(cdr(cdr(exp)))).getString()!='NIL':
errorObj = SExp.SExp(-4)
errorObj.string = 'Invalid Defun syntax'
return errorObj
if isPrimitive(key.getString()) :
errorObj = SExp.SExp(-4)
errorObj.string = 'Cannot replace primitives'
return errorObj
temp = cdr(exp)
val=cdr(temp)
res = chkParams(car(val),[])
if res == 'T':
tlst = getDefLst()
splt = val.getString().replace('(', ' ( ').replace(')',' ) ').replace('.',' . ').split()
if 'DEFUN' in splt:
errorObj = SExp.SExp(-4)
errorObj.string = 'Cannot Define function inside a UDF'
return errorObj
tlst[key.getString()]=val
setDefLst(tlst)
return key
else:
if res == -4:
errorObj = SExp.SExp(-4)
errorObj.string = 'Parameter Names Should Be Unique and non primitives'
return errorObj
return res
else:
return apply_function(car(exp),evlis(cdr(exp),alst,dLst),alst,dLst)
else:
errorObj = SExp.SExp(-4)
errorObj.string = 'Invalid Eval Expression'
return errorObj