#[1]Top [2]Concept Index [3]Table of Contents [4]SRFI-171 [5]SRFI-171 Transducers

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7.5.46.5 Helper functions for writing transducers

   These functions are in the (srfi srfi-171 meta) module and are only usable when
   you want to write your own transducers.

   Scheme Procedure: reduced value[10] ¶
          Wraps a value in a  container, signalling that the reduction
          should stop.

   Scheme Procedure: reduced? value[11] ¶
          Returns #t if value is a  record.

   Scheme Procedure: unreduce reduced-container[12] ¶
          Returns the value in reduced-container.

   Scheme Procedure: ensure-reduced value[13] ¶
          Wraps value in a  container if it is not already reduced.

   Scheme Procedure: preserving-reduced reducer[14] ¶
          Wraps reducer in another reducer that encapsulates any returned reduced
          value in another reduced container. This is useful in places where you
          re-use a reducer with [collection]-reduce. If the reducer returns a
          reduced value, [collection]-reduce unwraps it. Unless handled, this leads
          to the reduction continuing.

   Scheme Procedure: list-reduce f identity lst[15] ¶
          The reducing function used internally by list-transduce. f is a reducer as
          returned by a transducer. identity is the identity (sometimes called
          "seed") of the reduction. lst is a list. If f returns a reduced value, the
          reduction stops immediately and the unreduced value is returned.

   Scheme Procedure: vector-reduce f identity vec[16] ¶
          The vector version of list-reduce.

   Scheme Procedure: string-reduce f identity str[17] ¶
          The string version of list-reduce.

   Scheme Procedure: bytevector-u8-reduce f identity bv[18] ¶
          The bytevector-u8 version of list-reduce.

   Scheme Procedure: port-reduce f identity reader port[19] ¶
          The port version of list-reduce. It reduces over port using reader until
          reader returns the EOF object.

   Scheme Procedure: generator-reduce f identity gen[20] ¶
          The generator version of list-reduce. It reduces over gen until it returns
          the EOF object
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References

   1. http://www.gnu.org/software/guile/manual/html_node/index.html
   2. http://www.gnu.org/software/guile/manual/html_node/Concept-Index.html
   3. http://www.gnu.org/software/guile/manual/html_node/index.html#SEC_Contents
   4. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171.html
   5. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Transducers.html
   6. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Transducers.html
   7. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171.html
   8. http://www.gnu.org/software/guile/manual/html_node/index.html#SEC_Contents
   9. http://www.gnu.org/software/guile/manual/html_node/Concept-Index.html
  10. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-reduced
  11. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-reduced_003f
  12. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-unreduce
  13. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-ensure_002dreduced
  14. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-preserving_002dreduced
  15. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-list_002dreduce
  16. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-vector_002dreduce
  17. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-string_002dreduce
  18. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-bytevector_002du8_002dreduce
  19. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-port_002dreduce
  20. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Helpers.html#index-generator_002dreduce
  21. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171-Transducers.html
  22. http://www.gnu.org/software/guile/manual/html_node/SRFI_002d171.html
  23. http://www.gnu.org/software/guile/manual/html_node/index.html#SEC_Contents
  24. http://www.gnu.org/software/guile/manual/html_node/Concept-Index.html