==== Compilers Exam, 2017-01-10 ====
=== Programming Part ===

The following tasks should be solved in the order below. Write tests for each step!

  * Grade 2: Add a new regular expression to the lexer to describe time values of the form ''HH:MM'', where ''H'' and ''M'' can be any decimal digits.
  * Grade 3: Change the grammar to allow time values to be expressions.
  * Grade 4:
    * Add the following keywords: ''hour'', ''minute'' and ''time''.
    * Add the ''hour'' and ''minute'' functions to the grammar of the expressions. For example:
      * ''hour(12:38)''
      * ''minute(someVariable)''
    * Extend the variable declarations to allow time variables:
      * ''time someVariable;''
  * Grade 5: Extend the semantic analysis:
    * The parameters of ''hour'' and ''minute'' must be of type time. The return type of these functions is integer.
    * Assignment to a time variable has to be type correct as well.