I would like to make a simple password check routine in Genie, however I got stuck in a for loop. Here is the python code I want to mimic:
#-----------------------------------------------
# password_test.py
# example of if/else, lists, assignments,raw_input,
# comments and evaluations
#-----------------------------------------------
# Assign the users and passwords
users = ['Fred','John','Steve','Ann','Mary']
passwords = ['access','dog','12345','kids','qwerty']
#-----------------------------------------------
# Get username and password
usrname = raw_input('Enter your username => ')
pwd = raw_input('Enter your password => ')
#-----------------------------------------------
# Check to see if user is in the list
if usrname in users:
position = users.index(usrname) #Get the position in the list of the users
if pwd == passwords[position]: #Find the password at position
print 'Hi there, %s. Access granted.' % usrname
else:
print 'Password incorrect. Access denied.'
else:
print "Sorry...I don't recognize you. Access denied."
Here is as far I could get:
[indent=4]
init
users: array of string = {"Fred","John","Steve","Ann","Mary"}
passwords: array of string = {"access","dog","12345","kids","qwerty"}
print "Enter user name"
var usrname = stdin.read_line()
print "Enter password"
var pwd = stdin.read_line()
var position = 1
var i = 1
for i=0 to i < users.length
if (users[i]==usrname)
position += 1
if pwd == passwords[position]
print "Hi there, %d. Access granted."
else
print "Password incorrect. Access denied."
else
print "Sorry...I don't recognize you. Access denied."
However, I have been getting the error on the compiler:
$ valac evenmores.gs
evenmores.gs:15.18-15.18: error: syntax error, expected `do' but got `<' with previous identifier
for i=0 to i < users.length
^
Compilation failed: 1 error(s), 0 warning(s)
I also tried the for loop as suggested in here:
for (i = 0; i < users.length; i++)
With no avail. I would apreciate some help. Thanks.
You should remove var i = 1 and use for i:int = 0 to (users.length - 1)
There are a couple of points here:
for loop is used like this it is only to generate a number sequence. Be aware to generate a decreasing number sequence you need to use downto instead of to. A better way of iterating over an array is given belowfor loop you may have got the error "The name 'i' does not exist in the context of `main'" and this is why you added var i = 1. You can, however, declare the variable as part of the for loop as shown above. Generally for the fundamental types such as string and int I prefer to make the type explicit, but you can use type inference as well. for var i = 0 to (users.length -1) will also workTo iterate over an array it is better to use the for item in array syntax. For your example this would look like:
[indent=4]
init
users: array of string = {"Fred","John","Steve","Ann","Mary"}
passwords: array of string = {"access","dog","12345","kids","qwerty"}
print "Enter user name"
usrname:string = stdin.read_line()
print "Enter password"
pwd:string = stdin.read_line()
position:int = 0
for var user in users
if (user==usrname)
if pwd == passwords[position]
print "Hi there, %s. Access granted.", usrname
else
print "Password incorrect. Access denied."
else
print "Sorry...I don't recognize you. Access denied."
position++There is a fundamental problem with your code as you will see when you run it. I think a better solution would be to use a dictionary:
[indent=4]
init
var access = new dict of string,string
access[ "Fred" ] = "access"
access[ "John" ] = "dog"
access[ "Steve" ] = "12345"
access[ "Ann" ] = "kids"
access[ "Mary" ] = "qwerty"
print "Enter user name"
username:string = stdin.read_line()
print "Enter password"
pwd:string = stdin.read_line()
if !(username in access.keys)
print "Sorry...I don't recognize you. Access denied."
else
if pwd == access[ username ]
print "Hi there, %s. Access granted.", username
else
print "Password incorrect. Access denied."The key points:
libgee to work so you will need to install Gee and its development files. To build the program use valac --pkg gee-0.8 my_example.gs! operator is used and the in keyword. Note also the .keysaccess[ username ]