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Move structured import/export name information into the import/export…
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… string (#263)

* Move structured import/export name information into the string

Resolves #253

* Replace the junk byte with a fixed 0x00 byte
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@lukewagner
lukewagner authored Oct 27, 2023
1 parent fdc4997 commit 823beba
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82 changes: 32 additions & 50 deletions design/mvp/Binary.md
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Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,7 @@ instance ::= ie:<instanceexpr> => (i
instanceexpr ::= 0x00 c:<componentidx> arg*:vec(<instantiatearg>) => (instantiate c arg*)
| 0x01 e*:vec(<inlineexport>) => e*
instantiatearg ::= n:<string> si:<sortidx> => (with n si)
string ::= s:<core:name> => s
sortidx ::= sort:<sort> idx:<u32> => (sort idx)
sort ::= 0x00 cs:<core:sort> => core cs
| 0x01 => func
Expand All @@ -81,16 +82,6 @@ sort ::= 0x00 cs:<core:sort> => co
| 0x04 => component
| 0x05 => instance
inlineexport ::= n:<exportname> si:<sortidx> => (export n si)
string ::= s:<core:name> => s
name ::= len:<u32> n:<name-chars> => n (if len = |n|)
name-chars ::= l:<label> => l
| '[constructor]' r:<label> => [constructor]r
| '[method]' r:<label> '.' m:<label> => [method]r.m
| '[static]' r:<label> '.' s:<label> => [static]r.s
label ::= w:<word> => w
| l:<label> '-' w:<word> => l-w
word ::= w:[0x61-0x7a] x*:[0x30-0x39,0x61-0x7a]* => char(w)char(x)*
| W:[0x41-0x5a] X*:[0x30-0x39,0x41-0x5a]* => char(W)char(X)*
```
Notes:
* Reused Core binary rules: [`core:name`], (variable-length encoded) [`core:u32`]
Expand All @@ -104,25 +95,15 @@ Notes:
for aliases (below).
* Validation of `core:instantiatearg` initially only allows the `instance`
sort, but would be extended to accept other sorts as core wasm is extended.
* Validation of `instantiate` requires each `<name>`, `<iid>`, `<pkgid>` or
`<pkgidset>` in an `importname` in `c` to match a `string` in a `with`
argument and for the types to match.
* Validation of `instantiate` requires each `<importname>` in `c` to match a
`string` in a `with` argument (compared as strings) and for the types to
match.
* When validating `instantiate`, after each individual type-import is supplied
via `with`, the actual type supplied is immediately substituted for all uses
of the import, so that subsequent imports and all exports are now specialized
to the actual type.
* The indices in `sortidx` are validated according to their `sort`'s index
spaces, which are built incrementally as each definition is validated.
* Validation requires that annotated `name`s only occur on `func` imports or
exports and that the `r:<label>` matches the `name` of a preceding `resource`
import or export, respectively, in the same scope (component, component type
or instance type).
* Validation of `[constructor]` names requires that the `func` returns a
`(result (own $R))`, where `$R` is the resource labeled `r`.
* Validation of `[method]` names requires the first parameter of the function
to be `(param "self" (borrow $R))`, where `$R` is the resource labeled `r`.
* Validation of `[method]` and `[static]` names ensures that all field names
are disjoint.


## Alias Definitions
Expand Down Expand Up @@ -204,14 +185,15 @@ defvaltype ::= pvt:<primvaltype> => pvt
| 0x71 case*:vec(<case>) => (variant case*)
| 0x70 t:<valtype> => (list t)
| 0x6f t*:vec(<valtype>) => (tuple t+) (if |t*| > 0)
| 0x6e l*:vec(<label>) => (flags l+) (if |l*| > 0)
| 0x6d l*:vec(<label>) => (enum l*)
| 0x6e l*:vec(<label'>) => (flags l+) (if |l*| > 0)
| 0x6d l*:vec(<label'>) => (enum l*)
| 0x6b t:<valtype> => (option t)
| 0x6a t?:<valtype>? u?:<valtype>? => (result t? (error u)?)
| 0x69 i:<typeidx> => (own i)
| 0x68 i:<typeidx> => (borrow i)
labelvaltype ::= l:<label> t:<valtype> => l t
case ::= l:<label> t?:<valtype>? 0x00 => (case l t?)
labelvaltype ::= l:<label'> t:<valtype> => l t
case ::= l:<label'> t?:<valtype>? 0x00 => (case l t?)
label' ::= len:<u32> l:<label> => l (if len = |l|)
<T>? ::= 0x00 =>
| 0x01 t:<T> => t
valtype ::= i:<typeidx> => i
Expand Down Expand Up @@ -266,13 +248,12 @@ Notes:
* Validation rejects `resourcetype` type definitions inside `componenttype` and
`instancettype`. Thus, handle types inside a `componenttype` can only refer
to resource types that are imported or exported.
* The uniqueness validation rules for `importname` and `exportname`
described below are also applied at the instance- and component-type level.
* All parameter labels, result labels, record field labels, variant case
labels, flag labels, enum case labels, component import names, component
export names, instance import names and instance export names must be
unique in their containing scope.
* Validation of `externdesc` requires the various `typeidx` type constructors
to match the preceding `sort`.
* Validation of function parameter and result names, record field names,
variant case names, flag names, and enum case names requires that the name be
unique for the func, record, variant, flags, or enum type definition.
* (The `0x00` immediate of `case` may be reinterpreted in the future as the
`none` case of an optional immediate.)

Expand Down Expand Up @@ -329,20 +310,10 @@ flags are set.
(See [Import and Export Definitions](Explainer.md#import-and-export-definitions)
in the explainer.)
```ebnf
import ::= in:<importname> ed:<externdesc> => (import in ed)
export ::= en:<exportname> si:<sortidx> ed?:<externdesc>? => (export en si ed?)
exportname ::= 0x00 n:<name> => n
| 0x01 i:<iid'> => (interface i)
iid' ::= len:<u32> i:<iid> => "i" (if len = |i|)
importname ::= en:<exportname> => en
| 0x02 n:<name> s:<string> i?:<integrity'>? => n (url s i?)
| 0x03 n:<name> s:<string> i?:<integrity'>? => n (relative-url s i?)
| 0x04 n:<name> i:<integrity'> => n i
| 0x05 p:<pkgid'> i?:<integrity'>? => (locked-dep p i?)
| 0x06 p:<pkgidset'> => (unlocked-dep p)
pkgid' ::= len:<u32> p:<pkgid> => "p" (if len = |p|)
pkgidset' ::= len:<u32> p:<pkgidset> => "p" (if len = |p|)
integrity' ::= len:<u32> im:<integrity-metadata> => (integrity "im") (if len = |im|)
import ::= en:<importname'> ed:<externdesc> => (import in ed)
export ::= en:<exportname'> si:<sortidx> ed?:<externdesc>? => (export en si ed?)
importname' ::= 0x00 len:<u32> in:<importname> => in (if len = |in|)
exportname' ::= 0x00 len:<u32> en:<exportname> => en (if len = |en|)
```

Notes:
Expand All @@ -354,10 +325,21 @@ Notes:
(which disallows core sorts other than `core module`). When the optional
`externdesc` immediate is present, validation requires it to be a supertype
of the inferred `externdesc` of the `sortidx`.
* The `<name>`, `<iid>`, `<pkgid>` and `<pkgidset>` of imports must be relatively unique.
* The `<name>` and `<iid>` of exports must be relatively unique.
* `<iid>`, `<pkgid>` and `<pkgidset>` refer to the grammatical productions defined in
the [text format](#import-and-export-definitions).
* `<importname>` and `<exportname>` refer to the productions defined in the
[text format](Explainer.md#import-and-export-definitions).
* The `<importname>`s of a component must be unique and the `<exportname>`s of
a component must be unique as well (defined in terms of raw string equality).
* Validation requires that annotated `plainname`s only occur on `func` imports
or exports and that the first label of a `[constructor]`, `[method]` or
`[static]` matches the `plainname` of a preceding `resource` import or
export, respectively, in the same scope (component, component type or
instance type).
* Validation of `[constructor]` names requires that the `func` returns a
`(result (own $R))`, where `$R` is the resource labeled `r`.
* Validation of `[method]` names requires the first parameter of the function
to be `(param "self" (borrow $R))`, where `$R` is the resource labeled `r`.
* Validation of `[method]` and `[static]` names ensures that all field names
are disjoint.
* `<valid semver>` is as defined by [https://semver.org](https://semver.org/)
* `<integrity-metadata>` is as defined by the
[SRI](https://www.w3.org/TR/SRI/#dfn-integrity-metadata) spec.
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