exercism/elixir/new-passport/HINTS.md

Hints

General

• Read about using with in the official Getting Started guide.
• Review the functions available in the NaiveDateTime module, the Date module, and the Time module.

1. Get into the building

• Match the :ok tuple returned by enter_building/1 in with with <-.
• In the do part of with, return an :ok tuple with the value you just matched.
• Since you don't need to modify the error, you don't need an else block.

2. Go to the information desk and find which counter you should go to

• Match the :ok tuple returned by find_counter_information/1 in with with <-.
• Apply the anonymous function your just matched and match the result with <-.
• In the do part of with, return an :ok tuple with the counter you obtained.
• Add an else block that will expect a :coffee_break tuple and return a :retry tuple with a NaiveDateTime.
• A minute has 60 seconds.
• There is a built-in function that adds a given number of seconds to a NaiveDateTime struct.
• Other errors should be returned as they are.

3. Go to the counter and get your form stamped

• Match the :ok tuple returned by stamp_form/3 in with with <-.
• In the do part of with, return an :ok tuple with the checksum.

4. Receive your new passport

• In the do part of with, use get_new_passport_number/3 and return the result in an :ok tuple.