Clojure

Read/print round-trip for +/-Infinity and NaN

Details

  • Type: Defect Defect
  • Status: Open Open
  • Priority: Minor Minor
  • Resolution: Unresolved
  • Affects Version/s: Release 1.4
  • Fix Version/s: None
  • Component/s: None
  • Labels:
  • Patch:
    Code and Test
  • Approval:
    Triaged

Description

A few float-related forms (namely, Double/POSITIVE_INFINITY, Double/NEGATIVE_INFINITY, Double/NaN) are not eval-able after a round-trip via

(read-string (binding [*print-dup* true] (pr-str f))

The two options I see are to provide print-method implementations for these and their Float cousins, or to make Infinity, -Infinity, +Infinity, and NaN readable values. Since it sounds like edn may want to provide a spec for these values (see https://groups.google.com/d/topic/clojure-dev/LeJpOhHxESs/discussion and https://github.com/edn-format/edn/issues/2), I think making these values directly readable as already printed is preferable. Something like Double/POSITIVE_INFINITY seems too low-level from edn's perspective, as it would refer to a Java class and constant.

I'm attaching a patch implementing reader support for Infinity, -Infinity, +Infinity, and NaN.

Activity

Andy Fingerhut made changes -
Field Original Value New Value
Attachment clj-1074-read-infinity-and-nan-patch-v2.txt [ 12006 ]
Nicola Mometto made changes -
Andy Fingerhut made changes -
Attachment clj-1074-read-infinity-and-nan-patch-v2.txt [ 12006 ]
Alex Miller made changes -
Labels patch print reader
Alex Miller made changes -
Approval Triaged [ 10120 ]

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Dates

  • Created:
    Updated: