CODEWITHSUNDEEP
pythonvalagenie
lf_araujo
lf_araujo

Reputation: 2063

How to call GNU ReadLine in Genie

I know the stdin.read_line() function, but I wanted to make my code less verbose via the use or something more in line to raw_input() in python.

So I found out about GNU ReadLine in this discussion about vala, however I can`t reproduce it in Genie.

The python code that I want to mimic is:

loop = 1
while loop == 1:
    response = raw_input("Enter something or 'quit' to end => ")
    if response == 'quit':
        print 'quitting'
        loop = 0
    else:
        print 'You typed %s' % response

The far I could get was:

[indent=4]

init
    var loop = 1
    while loop == 1
        // print "Enter something or 'quit' to end => "
        var response = ReadLine.read_line("Enter something or 'quit' to end => ")
        if response == "quit"
            print "quitting"
            loop = 0
        else 
            print "You typed %s", response

And tried to compile with:

valac --pkg readline -X -lreadline loopwenquiry.gs

But I am getting the error:

loopwenquiry.gs:7.24-7.31: error: The name `ReadLine' does not exist in the context of `main'
        var response = ReadLine.read_line("Enter something or 'quit' to end => ")
                       ^^^^^^^^
loopwenquiry.gs:7.22-7.81: error: var declaration not allowed with non-typed initializer
        var response = ReadLine.read_line("Enter something or 'quit' to end => ")
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
loopwenquiry.gs:8.12-8.19: error: The name `response' does not exist in the context of `main'
        if response == "quit"
           ^^^^^^^^
loopwenquiry.gs:12.35-12.42: error: The name `response' does not exist in the context of `main'
            print "You typed %s", response
                                  ^^^^^^^^
Compilation failed: 4 error(s), 0 warning(s)

What am I doing wrong?

Thanks.

Upvotes: 0

Views: 107

Answers (1)

AlThomas
AlThomas

Reputation: 4289

As stated in the comment from Jens the namespace is Readline, not ReadLine. The function is also readline, not read_line. So your working code would be:

[indent=4]
init
    while true     
        response:string = Readline.readline("Enter something or 'quit' to end => ")
        if response == "quit"
            print "quitting"
            break
        else
            print "You typed %s", response

I notice you use valac --pkg readline -X -lreadline loopwenquiry.gs to compile, which is good. The -X -lreadline tells the linker to use the readline library. In most cases you won't need to do this because there is a pkg-config file, these have a .pc file extension, that contains all the necessary information. It looks as though someone has submitted a patch to fix this to the readline library. So using -X -llibrary_i_am_using should be the exception as most libraries have a .pc file.

I have also used while..break for the infinite loop to see if you think that is a slightly clearer style.

Upvotes: 1

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