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The interpreter pattern is well suited for situations when you want to represent a grandmother like

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a new language, musical notations, math equations and so on, oftentimes compilers use this pattern

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to interpret source code.

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As you can see in this UML diagram, an abstract expression interface or abstract class is at the base

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of this pattern.

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The terminal in terminal expressions are extending the substraction.

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The context contains the expression that will be evaluated using this design pattern, the terminal

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expressions are evaluated in their current form, whereas the terminal ones are evaluated again until

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the context is broken down into terminal expressions.

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Some of the weaknesses of this pattern is a complexity as a grammar can be a very complex resource to

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transpose in your code.

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Also, this pattern can be difficult to maintain as it requires a class for each rule which can increase

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the volume of the code.

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Let's see how we can implement this pattern.