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Use Infra terms to simplify text.
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* Define array keys as "byte sequence" and compare with "byte less than"
* Compare strings using "code unit less than"
* Make a few lists/sets the Infra types, and use items, contains, append, and so on.
* Simplify key comparison steps for non-equal types.
* Drop temp variables.
* Linkify "Assert:"
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@inexorabletash
inexorabletash committed Jun 12, 2019
1 parent ce86e18 commit 1e1241f
Showing 1 changed file with 58 additions and 91 deletions.
149 changes: 58 additions & 91 deletions index.bs
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Expand Up @@ -371,7 +371,7 @@ from the database. Ideally the user will never see this.
# Constructs # {#constructs}
<!-- ============================================================ -->

A <dfn>name</dfn> is a string equivalent to a {{DOMString}};
A <dfn>name</dfn> is a [=string=] equivalent to a {{DOMString}};
that is, an arbitrary sequence of 16-bit code units of any length,
including the empty string. [=/Names=] are always compared as
opaque sequences of 16-bit code units.
Expand Down Expand Up @@ -610,8 +610,8 @@ A [=/key=] also has an associated <dfn>value</dfn>, which will
be either:
an {{unrestricted double}} if type is *number* or *date*,
a {{DOMString}} if type is *string*,
a list of {{octet}}s if type is *binary*,
or a list of other [=/keys=] if type is *array*.
a [=byte sequence=] if type is *binary*,
or a [=/list=] of other [=/keys=] if type is *array*.

</div>

Expand All @@ -637,8 +637,8 @@ following the steps to [=convert a value to a key=].
</aside>

An <dfn>array key</dfn> is a [=/key=] with [=key/type=] *array*.
The <dfn>subkeys</dfn> of an [=array key=] are the members of the
[=array key=]'s [=key/value=] list.
The <dfn>subkeys</dfn> of an [=array key=] are the [=list/items=] of the
[=array key=]'s [=key/value=].

<div class=algorithm>

Expand All @@ -648,28 +648,17 @@ To <dfn>compare two keys</dfn> |a| and |b|, run these steps:

1. Let |tb| be the [=key/type=] of |b|.

1. If |ta| is *array* and |tb| is *binary*, *string*,
*date* or *number*, return 1.
1. If |ta| does not equal |tb|, then run these steps:

1. If |tb| is *array* and |ta| is *binary*, *string*,
*date* or *number*, return -1.

1. If |ta| is *binary* and |tb| is *string*, *date* or
*number*, return 1.

1. If |tb| is *binary* and |ta| is *string*, *date* or
*number*, return -1.

1. If |ta| is *string* and |tb| is *date* or *number*,
return 1.
1. If |tb| is *string* and |ta| is *date* or *number*,
return -1.

1. If |ta| is *date* and |tb| is *number*, return 1.

1. If |tb| is *date* and |ta| is *number*, return -1.

1. Assert: |ta| and |tb| are equal.
1. If |ta| is *array*, then return 1.
1. If |tb| is *array*, then return -1.
1. If |ta| is *binary*, then return 1.
1. If |tb| is *binary*, then return -1.
1. If |ta| is *string*, then return 1.
1. If |tb| is *string*, then return -1.
1. If |ta| is *date*, then return 1.
1. [=/Assert=]: |tb| is *date*.
1. Return -1.

1. Let |va| be the [=key/value=] of |a|.

Expand All @@ -688,50 +677,30 @@ To <dfn>compare two keys</dfn> |a| and |b|, run these steps:

<dt>*string*</dt>
<dd>
1. Let |length| be the lesser of |va|'s length and |vb|'s length.
1. Let |i| be 0.
1. While |i| is less than |length|, then:
1. Let |u| be the code unit of |va| at index |i|.
1. Let |v| be the code unit of |vb| at index |i|.
1. If |u| is greater than |v| then return 1.
1. If |u| is less than |v| then return -1.
1. Increase |i| by 1.
1. If |va|'s length is greater than |vb|'s length, then return 1.
1. If |va|'s length is less than |vb|'s length, then return -1.
1. If |va| is [=code unit less than=] |vb|, then return -1.
1. If |vb| is [=code unit less than=] |va|, then return 1.
1. Return 0.
</dd>

<dt>*binary*</dt>
<dd>
1. Let |length| be the lesser of |va|'s length and |vb|'s length.
1. Let |i| be 0.
1. While |i| is less than |length|, then:

1. Let |u| be the {{octet}} in |va| at index |i|.
1. Let |v| be the {{octet}} in |vb| at index |i|.
1. If |u| is greater than |v| then return 1.
1. If |u| is less than |v| then return -1.
1. Increase |i| by 1.

1. If |va|'s length is greater than |vb|'s length, then return 1.
1. If |va|'s length is less than |vb|'s length, then return -1.
1. If |va| is [=byte less than=] |vb|, then return -1.
1. If |vb| is [=byte less than=] |va|, then return 1.
1. Return 0.
</dd>

<dt>*array*</dt>
<dd>
1. Let |length| be the lesser of |va|'s length and |vb|'s length.
1. Let |length| be the lesser of |va|'s [=list/size=] and |vb|'s [=list/size=].
1. Let |i| be 0.
1. While |i| is less than |length|, then:

1. Let |u| be the [=/key=] in |va| at index |i|.
1. Let |v| be the [=/key=] in |vb| at index |i|.
1. Let |c| be the result of recursively running [=compare two keys=] with |u| and |v|.
1. Let |c| be the result of recursively running [=compare two keys=] with |va|[|i|] and |vb|[|i|].
1. If |c| is not 0, return |c|.
1. Increase |i| by 1.

1. If |va|'s length is greater than |vb|'s length, then return 1.
1. If |va|'s length is less than |vb|'s length, then return -1.
1. If |va|'s [=list/size=] is greater than |vb|'s [=list/size=], then return 1.
1. If |va|'s [=list/size=] is less than |vb|'s [=list/size=], then return -1.
1. Return 0.
</dd>
</dl>
Expand Down Expand Up @@ -762,9 +731,9 @@ of running [=compare two keys=] with |a| and |b| is 0.
</aside>

<aside class=note>
Members of *binary* keys are compared as unsigned {{octet}} values
(in the range [0, 255]) rather than signed {{byte}} values (in the range
[-128, 127]).
Members of *binary* keys are compared as unsigned [=byte=] values
(in the range 0 to 255 inclusive) rather than signed {{byte}} values (in the range
-128 to 127 inclusive).
</aside>


Expand Down Expand Up @@ -5565,7 +5534,7 @@ created [=/request=] belongs to is [=transaction/aborted=] using the steps to
1. Let |transaction| be the [=/transaction=] associated with
|source|.

1. Assert: |transaction|'s [=transaction/state=] is [=transaction/active=].
1. [=/Assert=]: |transaction|'s [=transaction/state=] is [=transaction/active=].

1. If |request| was not given, let |request| be a new |request| with
[=request/source=] as |source|.
Expand Down Expand Up @@ -6252,7 +6221,7 @@ To <dfn>iterate a cursor</dfn> with |targetRealm|, |cursor|, an optional

1. Let |direction| be |cursor|'s [=cursor/direction=].

1. Assert: if |primaryKey| is given, |source| is an [=/index=]
1. [=/Assert=]: if |primaryKey| is given, |source| is an [=/index=]
and |direction| is {{"next"}} or {{"prev"}}.

1. Let |records| be the list of [=object-store/records=] in |source|.
Expand Down Expand Up @@ -6475,7 +6444,7 @@ ECMAScript value or failure, or the steps may throw an exception.
[=evaluate a key path on a value=] using
|item| as |keyPath| and |value| as |value|.

1. Assert: |key| is not an [=abrupt completion=].
1. [=/Assert=]: |key| is not an [=abrupt completion=].

1. If |key| is failure, abort the overall algorithm and return
failure.
Expand All @@ -6484,7 +6453,7 @@ ECMAScript value or failure, or the steps may throw an exception.

1. Let |status| be [=CreateDataProperty=](|result|, |p|, |key|).

1. Assert: |status| is true.
1. [=/Assert=]: |status| is true.

1. Increase |i| by 1.

Expand Down Expand Up @@ -6543,7 +6512,7 @@ ECMAScript value or failure, or the steps may throw an exception.

</dl>

1. Assert: |value| is not an [=abrupt completion=].
1. [=/Assert=]: |value| is not an [=abrupt completion=].

1. Return |value|.

Expand Down Expand Up @@ -6577,9 +6546,9 @@ The result of these steps is either true or false.
1. Let |identifiers| be the result of <a lt="strictly split a string">strictly splitting</a>
|keyPath| on U+002E FULL STOP characters (.).

1. Assert: |identifiers| is not empty.
1. [=/Assert=]: |identifiers| is not empty.

1. Remove the last member of |identifiers|.
1. Remove the last [=list/item=] of |identifiers|.

1. [=list/For each=] remaining |identifier| of |identifiers|, if any:

Expand Down Expand Up @@ -6607,14 +6576,14 @@ To <dfn>inject a key into a value using a key path</dfn> with |value|, a |key| a
1. Let |identifiers| be the result of <a lt="strictly split a string">strictly splitting</a>
|keyPath| on U+002E FULL STOP characters (.).

1. Assert: |identifiers| is not empty.
1. [=/Assert=]: |identifiers| is not empty.

1. Let |last| be the last member of |identifiers| and remove it from
1. Let |last| be the last [=list/item=] of |identifiers| and remove it from
the list.

1. [=list/For each=] remaining |identifier| of |identifiers|:

1. Assert: |value| is an [=Object=] or an [=Array=].
1. [=/Assert=]: |value| is an [=Object=] or an [=Array=].

1. Let |hop| be [=!=] [=HasOwnProperty=](|value|, |identifier|).

Expand All @@ -6626,18 +6595,18 @@ To <dfn>inject a key into a value using a key path</dfn> with |value|, a |key| a
1. Let |status| be [=CreateDataProperty=](|value|, |identifier|,
|o|).

1. Assert: |status| is true.
1. [=/Assert=]: |status| is true.

1. Let |value| be [=!=] [=Get=](|value|, |identifier|).

1. Assert: |value| is an [=Object=] or an [=Array=].
1. [=/Assert=]: |value| is an [=Object=] or an [=Array=].

1. Let |keyValue| be the result of running [=convert a
key to a value=] with |key|.

1. Let |status| be [=CreateDataProperty=](|value|, |last|, |keyValue|).

1. Assert: |status| is true.
1. [=/Assert=]: |status| is true.

</div>

Expand Down Expand Up @@ -6675,17 +6644,17 @@ The steps return an ECMAScript value.
<dd>
1. Let |date| be the result of executing the ECMAScript Date
constructor with the single argument |value|.
1. Assert: |date| is not an [=abrupt completion=].
1. [=/Assert=]: |date| is not an [=abrupt completion=].
1. Return |date|.

</dd>

<dt>*binary*</dt>
<dd>
1. Let |len| be the length of |value|.
1. Let |len| be |value|'s [=byte sequence/length=].
1. Let |buffer| be the result of executing the ECMAScript
ArrayBuffer constructor with |len|.
1. Assert: |buffer| is not an [=abrupt completion=].
1. [=/Assert=]: |buffer| is not an [=abrupt completion=].
1. Set the entries in |buffer|'s
\[[ArrayBufferData]] internal slot to the entries
in |value|.
Expand All @@ -6697,17 +6666,16 @@ The steps return an ECMAScript value.
<dd>
1. Let |array| be the result of executing the ECMAScript Array
constructor with no arguments.
1. Assert: |array| is not an [=abrupt completion=].
1. Let |len| be the length of |value|.
1. [=/Assert=]: |array| is not an [=abrupt completion=].
1. Let |len| be |value|'s [=list/size=].
1. Let |index| be 0.
1. While |index| is less than |len|:

1. Let |entry| be the result of running
[=convert a key to a value=] with the |index|th
entry of |value| as input.
[=convert a key to a value=] with |value|[|index|].
1. Let |status| be [=CreateDataProperty=](|array|, |index|,
|entry|).
1. Assert: |status| is true.
1. [=/Assert=]: |status| is true.
1. Increase |index| by 1.

1. Return |array|.
Expand All @@ -6725,13 +6693,13 @@ The steps return an ECMAScript value.
<div class=algorithm>

To <dfn>convert a value to a key</dfn> with an ECMAScript value |input|, and an optional
set |seen|, run the following steps.
[=/set=] |seen|, run the following steps.
The result of these steps is a [=/key=] or invalid, or the
steps may throw an exception.

1. If |seen| was not given, let |seen| be a new empty set.
1. If |seen| was not given, then let |seen| be a new empty [=/set=].

1. If |input| is in |seen| return invalid.
1. If |seen| [=set/contains=] |input|, then return invalid.

1. Jump to the appropriate step below:

Expand Down Expand Up @@ -6774,12 +6742,12 @@ steps may throw an exception.
If |input| is a [=buffer source type=]</dt>
<dd>

1. Let |octets| be the result of running
1. Let |bytes| be the result of running
<a lt="get a copy of the buffer source">get a copy of the bytes held by the buffer source</a>
|input|. Rethrow any exceptions.

1. Return a new [=/key=] with [=key/type=]
*binary* and [=key/value=] |octets|.
*binary* and [=key/value=] |bytes|.

</dd>

Expand All @@ -6789,7 +6757,7 @@ steps may throw an exception.

1. Let |len| be [=?=] [=ToLength=]( [=?=] [=Get=](|input|,
"`length`")).
1. Add |input| to |seen|.
1. [=set/Append=] |input| to |seen|.
1. Let |keys| be a new empty list.
1. Let |index| be 0.
1. While |index| is less than |len|:
Expand All @@ -6809,7 +6777,7 @@ steps may throw an exception.
1. If |key| is invalid abort these steps and return
invalid.

1. Append |key| to |keys|.
1. [=list/Append=] |key| to |keys|.

1. Increase |index| by 1.

Expand All @@ -6835,9 +6803,9 @@ steps may throw an exception.

1. Let |len| be [=?=] ToLength( [=?=] [=Get=](|input|, "`length`")).

1. Let |seen| be a new set containing only |input|.
1. Let |seen| be a new [=/set=] containing only |input|.

1. Let |keys| be a new empty set.
1. Let |keys| be a new empty [=/list=].

1. Let |index| be 0.

Expand All @@ -6852,13 +6820,12 @@ steps may throw an exception.
|entry| and |seen|.

1. If |key| is not invalid or an [=abrupt completion=],
add |key| to |keys| if there are no other members of
|keys| [=equal to=] |key|.
and there is no [=list/item=] in |keys| [=equal to=] |key|,
then [=list/append=] |key| to |keys|.

1. Increase |index| by 1.

1. Return a new [=array key=] with [=key/value=] set to
a list of the members of |keys|.
1. Return a new [=array key=] with [=key/value=] set to |keys|.

1. Otherwise, return the result of running [=convert a
value to a key=] with argument |input|.
Expand Down

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