/boolean-expression-evaluator

Primary LanguageTypeScript

Skippet challenge

Task

Develop a system that will allow users to create and evaluate Boolean expressions based on user-defined values. The system should allow users to create their own boolean variables, from now own referred to as Args, and define custom logical operations, from now on referred to as Operations, which will be evaluated on-the-fly and presented to end-user, from now on called User, every time a system change might happen, ie. an Arg or an Operation is updated.

Defining Args

  • Users will be able to define a list of Args.
  • Users will able to add new Args by using an add button (eg. + add arg)
  • Each Arg will consist of two values, a name of type string and a truth value, which will be user-defined.
  • Users will be able to change each corresponding Arg values.
  • Every time an Arg value is updated the changes should be reflected in the Operation, and the final value should be recalculated.
  • The default name value of a new Arg should be equal to newarg${ID}, where ID a unique identifier, and the default value should be equal to false.

Out of scope

  • Users will not being able to delete Args once their defined.
  • We do not cover the case where two arguments have the same name and how the update should be resolved in the Operation.

Defining Operation

  • Users will be able to define custom Operation by combining Args or constant truth values with the basic binary operators and and or.
  • Constant truth values will be indicated by false and true in the UI of the app.
  • The and operator is used to represent conjuction.
  • The or operator is used to represent disjunction.
  • The list of available Args will be defined by the user (see previous section)
  • The User should be able to build the required Operation by composing basic Boolean operations.
  • New basic Boolean operations will be added using a button (eg. + add op)
  • The User should be able to delete a operation part. (Note: Deletion cannot happen on required operands. In that case just clear the value back to default.)
  • The User should be able to define nested operations that will be evaluated into a big Operation.
  • Deleting an operation should also delete all the nested operations.
  • When the user add a new operation, the default selected values should be blank and not affect the final result.
  • For conjunction and disjunction operations, do not allow users to remove their children if they are only two. These operations need at least two operands to function.