Picat Using Standard Modules Questions and Answers

Question 1

A developer needs to get a list of all files and directories in the current working directory. Which predicate from the `os` module should be used for this purpose?

Accepted Answer

os:listdir(".", List)

Answer

os:files(.)

Answer

os:scandir(".", List)

Answer

os:list_files(List)

Question 2

When processing a list of numerical data, you need to find the sum of all elements. Which function from the `math` module accomplishes this?

Accepted Answer

math:sum/1

Answer

math:total/1

Answer

math:aggr/1

Answer

math:add_all/1

Question 3

A Picat script needs to be executed from the command line with several arguments. How can the script access these arguments?

Accepted Answer

By calling `sys:get_args()`

Answer

By calling `os:get_cmd_args()`

Answer

By accessing the built-in `ARGS` list

Answer

By reading from the `io:stdin` stream

Question 4

You need to combine two lists, `L1` and `L2`, into a single list of pairs, where each pair contains one element from `L1` and one from `L2` at the corresponding position. Which predicate from the `util` module is designed for this?

Accepted Answer

util:zip(L1, L2, Pairs)

Answer

util:join(L1, L2, Pairs)

Answer

util:combine(L1, L2, Pairs)

Answer

util:merge(L1, L2, Pairs)

Question 5

A developer needs to read the entire content of a text file named `config.txt` into a single string. Which function from the `io` module should be used?

Accepted Answer

io:read_file_to_string("config.txt")

Answer

io:get_file_contents("config.txt")

Answer

io:read_all("config.txt")

Answer

io:read_file("config.txt")

Question 6

To execute an external command-line program (e.g., `ls -l` or `dir`) from within a Picat script and capture its output, which predicate is most suitable?

Accepted Answer

os:shell(Command, Output)

Answer

sys:run(Command, Output)

Answer

io:execute(Command, Output)

Answer

os:cmd(Command, Output)