Kevin Reid: various renamings, extra links

2009-01-14T00:29:22Z

various renamings, extra links

New page

The [[Equalizer]] implements the algorithm for testing [[sameness]].

{{XXX}} explain further

An Equalizer is present in the [[universal environment]].

? __equalizer
# value: <equalizer>

== Protocol ==

? def unresolved := [[Object Ref#promise/0|Ref.promise]]()[0]
# value: <Promise>

{{instance msgdoc|sameEver|2|<var>a</var>, <var>b</var>|[[Boolean]]}}

{|
! When optSame returns !! sameEver
|-
| [[false]] || returns false
|-
| [[true]] || returns true
|-
| [[null]] || [[throw]]s [[NotSettledException]]
|}

(XXX don't use sugar?)

? 1 == 1
# value: true

? 1 == 2
# value: false

? 1 == unresolved
# problem: <insufficientlySettledException: not sufficiently settled: 1 == <Promise>>

? def _ {} == unresolved
# problem: <insufficientlySettledException: not sufficiently settled: <_> == <Promise>>

{{instance msgdoc|sameYet|2|<var>a</var>, <var>b</var>|[[Boolean]]}}

{|
! When optSame returns !! sameYet
|-
| [[false]] || returns false
|-
| [[true]] || returns true
|-
| [[null]] || returns false
|}

? __equalizer.sameYet(1, 1)
# value: true

? __equalizer.sameYet(1, 2)
# value: false

? __equalizer.sameYet(1, unresolved)
# value: false

{{instance msgdoc|optSame|2|<var>a</var>, <var>b</var>|nullOk<nowiki>[</nowiki>[[Boolean]]]}}

{{XXX}} write documentation

{{instance msgdoc|isSettled|1|<var>a</var>|[[Boolean]]}}

{{XXX}} This is a proposed change, implemented in [[E-on-CL]]: that the isSettled operation be moved from [[Object Ref]] to Equalizer, since the definition of settledness is tightly related to the definition of sameness.

{{XXX}} write tests

{{instance msgdoc|makeTraversalKey|1|<var>a</var>|[[TraversalKey]]}}

{{XXX}} See comment and rationale on isSettled.

==Tests==

{{XXX}} Discuss whether these tests should be placed on this page or on [[Sameness]], and whether these tests should be broken up by method documentation sections or all together like this.

{{XXX}} review whether these tests have good coverage (they were compiled by TDD in [[E-on-CL]]).

Just defining some objects to use later:

? [[DefineExpr|def]] makeCoercedSlot := <elib:slot.makeCoercedSlot>; [[null]]

# {{XXX}} we should define our semitransparent type here, not rely on CoercedSlot being this incidentally

? [[ObjectExpr|def]] a {}
# value: <a>

? [[ObjectExpr|def]] b {}
# value: <b>

? def semiA1 := makeCoercedSlot(any, 1, null)
> def semiA2 := makeCoercedSlot(any, 1, null)
> def semiB := makeCoercedSlot(any, 2, null)
> def semiU := makeCoercedSlot(any, Ref.promise()[0], null)
>null

===Algorithm checking===

Two [[selfish]] objects are different.

? __equalizer.optSame(a, b)
# value: false

A selfish object is the same as itself.

? __equalizer.optSame(a, a)
# value: true

An [[atomic selfless]] object is the same as any object with the same value.

? [1, 1000000000000000000001 - 1000000000000000000000]
# value: [1, 1]

? __equalizer.optSame(1, 1.0)
# value: false

? __equalizer.optSame(1, 1000000000000000000001 - 1000000000000000000000)
# value: true

A [[transparent selfless]] object is the same as any object with the same [[portrayal]] as from [[Miranda optUncall/1|__optUncall]].

? __equalizer.optSame([1], [1])
# value: true

? __equalizer.optSame([1], [2])
# value: false

An unresolved reference is the same as itself, but not the same or different as anything else.

{{XXX}} fix all updoc impls and eliminate use of [null] gimmick

? [__equalizer.optSame(1, unresolved)]
# value: [null]

? [__equalizer.optSame(unresolved, unresolved)]
# value: [true]

? [__equalizer.optSame([unresolved], [unresolved])]
# value: [true]

? [__equalizer.optSame(unresolved, Ref.promise()[0])]
# value: [null]

Cyclic Selfless objects are the same as each other provided they have the same structure.

? [__equalizer.optSame(def circle := [circle], def loop := [loop])]
# value: [true]

? [__equalizer.optSame(def circle := [1, [1, circle]], def loop := [1, loop])]
# value: [true]

More Selfless (XXX move these?)

? [__equalizer.optSame('q', 'q')]
# value: [true]

? [__equalizer.optSame('q', 'w')]
# value: [false]

? "a" + "bc"
# value: "abc"

? [__equalizer.optSame("abc", "a" + "bc")]
# value: [true]

A String is a kind of list but it isn't the same as a plain ConstList.

? [__equalizer.optSame(['a', 'b', 'c'], "a" + "bc")]
# value: [false]

Tests of semitransparency ({{XXX}} document this; currently only actually implemented in general in [[E-on-CL]]; semitransparency is the general case of what [[SturdyRef]], and now [[CoercedSlot]] is):

? [__equalizer.optSame(semiA1, semiA2)]
# value: [true]

? [__equalizer.optSame(semiA1, semiB)]
# value: [false]

? [__equalizer.optSame(semiA1, semiU)]
# value: [null]

This is a test for a former bug in [[E-on-CL]]: the sofar list was sometimes being filled with the right-side reference only (broken sort-by-hash swap), so a cycle on the right would be assumed to be a cycle on the left as well. The test is done with two sets of references because whether the swap occurs depends on the hash-values involved.

? def l1 := <nowiki>[[[l1]]]</nowiki>
> def c1 := <nowiki>[[[[[['a']]]]]]</nowiki>
> def l2 := <nowiki>[[[l2]]]</nowiki>
> def c2 := <nowiki>[[[[[['b']]]]]]</nowiki>
> [c1 == l1, c1 == l2, c2 == l1, c2 == l2,
> l1 == c1, l1 == c2, l2 == c1, l2 == c2]
# value: [false, false, false, false, false, false, false, false]

===isSettled===

? __equalizer.isSettled(semiA1)
# value: true

? __equalizer.isSettled(semiU)
# value: false

{{XXX}} there are other isSettled tests from E-on-CL to be moved here

[[Category:ELib specification]]

Kevin Reid: add tests from eocl, some doc

2009-01-11T17:17:35Z

add tests from eocl, some doc

Show changes

Kevin Reid: fix arities

2009-01-11T15:43:25Z

fix arities

←Older revision		Revision as of 15:43, 11 January 2009
Line 5:		Line 5:
	== Protocol ==		== Protocol ==

-	{{instance msgdoc\|sameEver\|1\|<var>a</var>, <var>b</var>\|[[Boolean]]}}	+	{{instance msgdoc\|sameEver\|2\|<var>a</var>, <var>b</var>\|[[Boolean]]}}

	{{XXX}} write documentation and tests		{{XXX}} write documentation and tests

-	{{instance msgdoc\|sameYet\|1\|<var>a</var>, <var>b</var>\|[[Boolean]]}}	+	{{instance msgdoc\|sameYet\|2\|<var>a</var>, <var>b</var>\|[[Boolean]]}}

	{{XXX}} write documentation and tests		{{XXX}} write documentation and tests

-	{{instance msgdoc\|optSame\|1\|<var>a</var>, <var>b</var>\|nullOk<nowiki>[</nowiki>[[Boolean]]]}}	+	{{instance msgdoc\|optSame\|2\|<var>a</var>, <var>b</var>\|nullOk<nowiki>[</nowiki>[[Boolean]]]}}

	{{XXX}} write documentation and tests		{{XXX}} write documentation and tests

Kevin Reid: add isSettled, makeTraversalKey

2009-01-11T15:42:22Z

add isSettled, makeTraversalKey

←Older revision		Revision as of 15:42, 11 January 2009
Line 17:		Line 17:
	{{XXX}} write documentation and tests		{{XXX}} write documentation and tests

		+	{{instance msgdoc\|isSettled\|1\|<var>a</var>\|[[Boolean]]}}
		+
		+	{{XXX}} This is a proposed change, implemented in [[E-on-CL]]: that the isSettled operation be moved from [[Ref (object)]] to Equalizer, since the definition of settledness is tightly related to the definition of sameness.
		+
		+	{{XXX}} write tests
		+
		+	{{instance msgdoc\|makeTraversalKey\|1\|<var>a</var>\|[[TraversalKey]]}}
		+
		+	{{XXX}} See comment and rationale on isSettled.

	{{stub}}		{{stub}}
	[[Category:ELib specification]]		[[Category:ELib specification]]

Kevin Reid at 15:34, 11 January 2009