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Returns a sequence that contains the elements of seq (which must be single-valued), but
only until the last element for which applying pred to the element produces #t, after which
the sequence ends.
(stop-after seq pred) → sequence
seq : sequence
pred : (any/c . -> . any)
Returns a sequence that contains the elements of seq (which must be single-valued), but
only until the element (inclusive) for which applying pred to the element produces #t, after
which the sequence ends.
(make-do-sequence thunk) → sequence
thunk : (-> (values (any/c . -> . any)
(any/c . -> . any/c)
any/c
(any/c . -> . any/c)
(() () #:rest list . ->* . any/c)
((any/c) () #:rest list . ->* . any/c)))
Returns a sequence whose elements are generated by the procedures and initial value returned
by the thunk. The generator is defined in terms of a position, which is initialized to
the third result of the thunk, and the element, which may consist of multiple values.
The thunk results define the generated elements as follows:
• The first result is a pos->element procedure that takes the current position and returns
the value(s) for the current element.
• The second result is a next-pos procedure that takes the current position and returns
the next position.
• The third result is the initial position.
• The fourth result takes the current position and returns a true result if the sequence
includes the value(s) for the current position, and false if the sequence should end
instead of including the value(s).
• The fifth result is like the fourth result, but it takes the current element value(s) instead
of the current position.
• The sixth result is like the fourth result, but it takes both the current position and the
current element values(s) and determines a sequence end after the current element is
already included in the sequence.
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