describe-coops

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Display textual descriptions of built-in objects, user-created records, and coops objects.

Overview

describe-coops provides the same API as describe but additionally supports coops objects.

The only API difference is the addition of a describe-object generic procedure, with a useful default implementation for coops classes and objects. If coops-primitive-objects is loaded, you can specialize on primitive objects as well.

Usage

(use describe-coops)

There's no need to load describe, as this egg loads describe itself and exports a compatible API. Loading describe after describe-coops will wipe out the REPL shortcuts.

REPL

The REPL shortcuts -- ,d and friends -- provided by the describe egg are extended to support coops objects.

API

describe obj #!optional outprocedure

Prints a textual description of OBJ to output port OUT, which defaults to (current-output-port). For coops objects, this dispatches to describe-object; otherwise it calls describe from the describe egg.

Note that this is not a generic procedure.

describe-object obj outprocedure

Generic procedure specialized on OBJ, responsible for printing the textual description of OBJ. describe calls this under the hood.

#;> (define-class <point> () (x y z))

#;> (describe <point>)
coops standard-class <point>
  class precedence list: (<standard-object>)
  slots: (x y z)

#;> (describe (make <point> 'x 1 'y 2 'z 3))
coops instance of class <point>:
  x : 1
  y : 2
  z : 3

#;> (define-method (describe-object (obj <point>) out)
      (fprintf out "<point> object with coordinates (~A, ~A, ~A)~%"
       (slot-value obj 'x) (slot-value obj 'y) (slot-value obj 'z)))

#;> (describe (make <point> 'x 1 'y 2 'z 3))
<point> object with coordinates (1, 2, 3)

If coops-primitive-objects is loaded, you can specialize on primitive objects such as fixnums; the default implementation prints both the object's class and the describe egg's description. For example:

#;> (describe 3)
exact integer 3 (#x3 #o3 #b11 #\x3)
#;> (use coops-primitive-objects)
#;> (describe 3)
coops instance of primitive class <fixnum>
exact integer 3 (#x3 #o3 #b11 #\x3)

describe-sequence-limit nparameter

set-describer! tag procprocedure

dump obj #!optional offset length outprocedure

hexdump bv start end ref outprocedure