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  2. Haskell features - Wikipedia

    en.wikipedia.org/wiki/Haskell_features

    In the Haskell source immediately below, :: can be read as "has type"; a -> b can be read as "is a function from a to b". (Thus the Haskell calc :: String -> [Float] can be read as "calc has type of a function from Strings to lists of Floats".)

  3. Option type - Wikipedia

    en.wikipedia.org/wiki/Option_type

    In programming languages (especially functional programming languages) and type theory, an option type or maybe type is a polymorphic type that represents encapsulation of an optional value; e.g., it is used as the return type of functions which may or may not return a meaningful value when they are applied.

  4. Short-circuit evaluation - Wikipedia

    en.wikipedia.org/wiki/Short-circuit_evaluation

    Short-circuit evaluation, minimal evaluation, or McCarthy evaluation (after John McCarthy) is the semantics of some Boolean operators in some programming languages in which the second argument is executed or evaluated only if the first argument does not suffice to determine the value of the expression: when the first argument of the AND function evaluates to false, the overall value must be ...

  5. Double-checked locking - Wikipedia

    en.wikipedia.org/wiki/Double-checked_locking

    Intuitively, this algorithm is an efficient solution to the problem. But if the pattern is not written carefully, it will have a data race. For example, consider the following sequence of events: Thread A notices that the value is not initialized, so it obtains the lock and begins to initialize the value.

  6. Mediator pattern - Wikipedia

    en.wikipedia.org/wiki/Mediator_pattern

    In the following example, a Mediator object controls the values of several Storage objects, forcing the user code to access the stored values through the mediator. When a storage object wants to emit an event indicating that its value has changed, it also goes back to the mediator object (via the method notifyObservers ) that controls the list ...

  7. Extraneous and missing solutions - Wikipedia

    en.wikipedia.org/wiki/Extraneous_and_missing...

    However, more insidious are missing solutions, which can occur when performing operations on expressions that are invalid for certain values of those expressions. For example, if we were solving the following equation, the correct solution is obtained by subtracting from both sides, then dividing both sides by :

  8. Optimal stopping - Wikipedia

    en.wikipedia.org/wiki/Optimal_stopping

    A key example of an optimal stopping problem is the secretary problem. Optimal stopping problems can often be written in the form of a Bellman equation , and are therefore often solved using dynamic programming .

  9. Duality (optimization) - Wikipedia

    en.wikipedia.org/wiki/Duality_(optimization)

    Another condition in which the min-max and max-min are equal is when the Lagrangian has a saddle point: (x∗, λ∗) is a saddle point of the Lagrange function L if and only if x∗ is an optimal solution to the primal, λ∗ is an optimal solution to the dual, and the optimal values in the indicated problems are equal to each other. [18 ...