Basic Examples (3) 

Evaluate a sequence of expressions, "reaping" ones that have been "sown":

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Compute a sum, "reaping" i^2 "sown" at each step:

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Make a separate key for each tag being reaped:

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Scope (2) 

If nothing is sown, an empty association will be returned in the "Sown" key:

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Count the number of instances of each integer, separating the negative:

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Generalizations & Extensions (1) 

Apply f to each distinct key and list of values:

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Applications (2) 

Find the list of values sampled by Plot:

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Remove duplicates from a list, keeping the original order:

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This is like Union without the sorting:

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Properties & Relations (4) 

If no expressions are sown, ReapAssociation returns an empty association of expressions it has reaped:

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ReapAssociation collects expressions in exactly the order they are sown:

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The list associated with the first tag to be encountered will be the first key:

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When the order of tags is not known, ReapAssociation can make it easier to understand results compared to Reap:

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Neat Examples (1) 

Create an animation showing the full stack history of an evaluation:

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