Reap

Reap[expr] gives the value of expr together with all expressions to which Sow has been applied during its evaluation.

Expressions sown using Sow[e] or Sow[e, ] with different tags are given in different lists.

Reap[expr, patt] reaps only expressions sown with tags that match patt.

Reap[expr, , , ... ] puts expressions associated with each of in a separate list.

Reap[expr, patt, f] returns expr, f[, , , ... ], ... .

Sow and Reap provide a convenient way to accumulate a list of intermediate results in a computation.

Reap accumulates expressions in the order in which Sow is applied to them.

Expressions sown with a particular tag are collected by the innermost Reap whose pattern matches the tag.

Reap[expr] is equivalent to Reap[expr, _].

Reap has attribute HoldFirst.

See Section 2.4.1 and Section 2.6.10.

See also: Sow, Catch, AppendTo, Print.

New in Version 5.0.

Further Examples