Improve binding operator table readability

proposals/webidl-bindings/Explainer.md

@@ -168,32 +168,29 @@ operators** and maps from a **source tuple** of WebAssembly values to a
 **destination tuple** of Web IDL values (although currently only one is ever
 produced). A sample list of outgoing binding operators:
 
-| Binding Operator                                          | Description |
-| :---                                         | :---        |
-| **operator** immediates *children*   				 | |
-| **as** webidl-type idx 					   			     | Takes the `idx`'th wasm value of the source tuple and produces a Web IDL value of `webidl-type`, allowing only trivial conversions (like `i32` to [`long`] or `anyref` to [`any`]). |
-| **utf8-str** webidl-type off-idx len-idx     | Takes the `off-idx`'th and `len-idx`th wasm values of the source tuple, which must both be `i32`s, as the offset and length, resp., of a UTF-8 string in linear memory and decodes a `webidl-type`, which must be one of [`DOMString`], [`ByteString`] or [`USVString`]. |
-| **utf8-cstr** webidl-type off-idx			       | Like `utf8-str`, but instead of length being explicitly supplied as a wasm value in the source tuple, the length is found by decoding up to the first null code point. |
-| **i32-to-enum** webidl-type val-idx		       | Takes the `val-idx`'th wasm value of the source tuple, which must be an `i32`, as an index into the list of strings specified by `webidl-type`, which must be an [Enumeration]. |
-| **view** webidl-type off-idx len-idx         | Takes the `off-idx`'th and `len-idx`'th wasm values of the source tuple, which must both be `i32`s, as the offset and length, resp., of a new `webidl-type`, which must be a [Typed Array View]. |
-| **dict** webidl-type *out-exprs*			       | Create a Web IDL `webidl-type` [Dictionary] value using `out-exprs` as the field values (which must line up with `webidl-type` exactly). |
-| **bind-export** webidl-type binding func-idx | Takes the `func-idx`'th wasm value of the source tuple, which must be a typed function [`ref`], and applies `binding` to produce a [Callback] value. (See [`BindExport`](#runtime) below.) |
+| Operator | Immediates | Children | Description |
+| :---     | :---       | :---     | :---        |
+| **as** | webidl‑type<br>idx | | Takes the `idx`'th wasm value of the source tuple and produces a Web IDL value of `webidl-type`, allowing only trivial conversions (like `i32` to [`long`] or `anyref` to [`any`]). |
+| **utf8‑str** | webidl‑type<br>off‑idx<br>len‑idx | | Takes the `off-idx`'th and `len-idx`th wasm values of the source tuple, which must both be `i32`s, as the offset and length, resp., of a UTF-8 string in linear memory and decodes a `webidl-type`, which must be one of [`DOMString`], [`ByteString`] or [`USVString`]. |
+| **utf8‑cstr** | webidl‑type<br>off‑idx	| | Like `utf8-str`, but instead of length being explicitly supplied as a wasm value in the source tuple, the length is found by decoding up to the first null code point. |
+| **i32‑to‑enum** | webidl‑type<br>val‑idx	| | Takes the `val-idx`'th wasm value of the source tuple, which must be an `i32`, as an index into the list of strings specified by `webidl-type`, which must be an [Enumeration]. |
+| **view** | webidl‑type<br>off‑idx<br>len‑idx | | Takes the `off-idx`'th and `len-idx`'th wasm values of the source tuple, which must both be `i32`s, as the offset and length, resp., of a new `webidl-type`, which must be a [Typed Array View]. |
+| **dict** | webidl‑type | *out‑exprs* | Create a Web IDL `webidl-type` [Dictionary] value using `out-exprs` as the field values (which must line up with `webidl-type` exactly). |
+| **bind‑export** | webidl‑type<br>binding<br>func‑idx | | Takes the `func-idx`'th wasm value of the source tuple, which must be a typed function [`ref`], and applies `binding` to produce a [Callback] value. (See [`BindExport`](#runtime) below.) |
 
 An **incoming binding expression** is composed of **incoming binding
 operators** and maps from a source tuple of Web IDL values to a **destination
 tuple** of WebAssembly values.  A sample list of incoming binding operators:
 
-
-| Binding&nbsp;Operator&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; | Description |
-| :---                                         | :---        |
-| **operator** immediates *children*   				 | |
-| **get** idx															     | Return the `idx`th Web IDL value of the source tuple. |
-| **as** wasm-type *in-expr* 							     | Take the result of `in-expr`, which can be any Web IDL value, and produces a wasm value of `wasm-type`, allowing only trivial conversions (like [`long`] to `i32` or [`any`] to `anyref`). |
-| **alloc-utf8-str** alloc-func-idx *in-expr*  | Take the result of `in-expr`, which must be one of [`DOMString`], [`ByteString`] or [`USVString`], compute the number of bytes necessary to store a UTF-8 encoding of this string, call the `alloc-func-idx`'th function of the receiving instance, passing the number of bytes and using the resulting offset to store the UTF-8 encoding, finally returning the offset and byte-length as two `i32`s (and trapping on OOM). |
-| **alloc-buffer** alloc-func-idx *in-expr*    | Take the result of `in-expr`, which must be a [BufferSource], call the `alloc-func-idx`'th function of the receiving instance, passing the BufferSource's length and using the resulting offset to store a copy of the BufferSource in linear memory, returning the offset and byte-length as two `i32`s (and trapping on OOM). |
-| **enum-to-i32** webidl-type *in-expr* 		   | Take the result of `in-expr`, which must be an [Enumeration] value, and reverse-map this string to the `i32` index of the matching string in the `webidl-type`, which must also be an Enumeration. |
-| **field** field-idx *in-expr*								 | Take the result of `in-expr`, which must be a [Dictionary] value, and return the Web IDL value of the `field-idx`th field. |
-| **bind-import** wasm-type binding *in-expr*  | Take the result of `in-expr`, which must be a [Callback] value, and apply `binding` to produce a [`funcref`]  (or, later, a typed function reference). (See [`BindImport`](#runtime) below.) |
+| Operator | Immediates | Children | Description |
+| :---     | :---       | :---     | :---        |
+| **get** | idx	| |	Return the `idx`th Web IDL value of the source tuple. |
+| **as** | wasm‑type | *in‑expr* | Take the result of `in-expr`, which can be any Web IDL value, and produces a wasm value of `wasm-type`, allowing only trivial conversions (like [`long`] to `i32` or [`any`] to `anyref`). |
+| **alloc‑utf8‑str** | alloc‑func‑idx | *in‑expr* | Take the result of `in-expr`, which must be one of [`DOMString`], [`ByteString`] or [`USVString`], compute the number of bytes necessary to store a UTF-8 encoding of this string, call the `alloc-func-idx`'th function of the receiving instance, passing the number of bytes and using the resulting offset to store the UTF-8 encoding, finally returning the offset and byte-length as two `i32`s (and trapping on OOM). |
+| **alloc‑buffer** | alloc‑func‑idx | *in‑expr* | Take the result of `in-expr`, which must be a [BufferSource], call the `alloc-func-idx`'th function of the receiving instance, passing the BufferSource's length and using the resulting offset to store a copy of the BufferSource in linear memory, returning the offset and byte-length as two `i32`s (and trapping on OOM). |
+| **enum‑to‑i32** | webidl‑type | *in‑expr* | Take the result of `in-expr`, which must be an [Enumeration] value, and reverse-map this string to the `i32` index of the matching string in the `webidl-type`, which must also be an Enumeration. |
+| **field** | field‑idx | *in‑expr*	| Take the result of `in-expr`, which must be a [Dictionary] value, and return the Web IDL value of the `field-idx`th field. |
+| **bind‑import** | wasm‑type<br>binding | *in‑expr* | Take the result of `in-expr`, which must be a [Callback] value, and apply `binding` to produce a [`funcref`]  (or, later, a typed function reference). (See [`BindImport`](#runtime) below.) |
 
 For example, building on the previous section's example, a Web IDL value of the
 `$Contact` dictionary type could be produced from three WebAssembly `i32`s by