Addressed (some) comments

Author: teofr

crates/solidity-v2/inputs/language/src/BREAKING_CHANGES.md

@@ -28,29 +28,31 @@ We should consider adding validation for these at a later stage if needed:
 - `HexLiteral` and `YulHexLiteral` and `DecimalLiteral` and `YulDecimalLiteral`:
     - It was illegal for them to be followed by `IdentifierStart`. Now we will produce two separate tokens rather than rejecting it.
 
-## Language Definition Changes
+## Grammar
 
 The following changes modify the language definition to support the new parser and resolve grammar ambiguities.
 In some cases we also try to simplify the model.
 
 ### AddressKeyword
 
 - Made the `address` keyword reserved in all versions, handling the few cases where it can be used as an identifier separately.
-- `MemberAccessIdentifier` handles the cases where `address` can be used as an `Identifier`, either in an `IdentifierPath` or a `MemberAccessExpression`.
+- `IdentifierPathElement` handles the cases where `address` can be used as an `Identifier`, either in an `IdentifierPath` or a `MemberAccessExpression`.
 
-### MemberAccessIdentifier
+### IdentifierPathElement
 
-New enum added to allow the reserved `address` keyword in member access expressions (from Solidity 0.6.0):
+New enum added to allow the reserved `address` keyword in identifier paths and member access expressions
+(from Solidity 0.6.0):
 
 - Variants: `Identifier` | `AddressKeyword` (enabled from 0.6.0)
-- Used in `MemberAccessExpression` (previously just `Identifier`) and in `IdentifierPathTailElements` (for identifier path tails)
+- Used in `MemberAccessExpression` and in `IdentifierPath`
 
 ### IdentifierPath
 
-Changed from a simple `Separated` list to a structured format to allow the reserved `address` keyword to appear in identifier paths (but not as the head):
+Changed from a `Separated` list of `Identifier`, to a list of `IdentifierPathElement`, to capture the reserved
+`AddressKeyword` as part of the path.
 
 - **Before**: `Separated(name = IdentifierPath, reference = Identifier, separator = Period)`
-- **After**: `Struct` with `head: Identifier` and `tail: Optional<IdentifierPathTail>`, where `IdentifierPathTail` contains a `Period` separator followed by `IdentifierPathTailElements` (a `Separated` list of `MemberAccessIdentifier`).
+- **After**: `Separated(name = IdentifierPath, reference = IdentifierPathElement, separator = Period)`
 
 ### TupleDeconstructionStatement
 

crates/solidity-v2/inputs/language/src/definition.rs

@@ -496,7 +496,7 @@ language_v2_macros::compile!(Language(
                             // `address` is a reserved keyword, but it can still be used as an identifier in some contexts,
                             // in particular as a member access (e.g., `myPayload.address`) or as an identifier
                             // path
-                            // See `MemberAccessIdentifier` for details
+                            // See `IdentifierPathElement` for details
                             name = AddressKeyword,
                             identifier = Identifier,
                             definitions = [KeywordDefinition(value = Atom("address"))]
@@ -3528,7 +3528,7 @@ language_v2_macros::compile!(Language(
                                         model = Postfix,
                                         fields = (
                                             period = Required(Period),
-                                            member = Required(MemberAccessIdentifier)
+                                            member = Required(IdentifierPathElement)
                                         )
                                     )]
                                 ),
@@ -3580,14 +3580,6 @@ language_v2_macros::compile!(Language(
                                 colon = Required(Colon),
                                 end = Optional(reference = Expression)
                             )
-                        ),
-                        Enum(
-                            // A member access can be either an identifier or the reserved `address` keyword
-                            name = MemberAccessIdentifier,
-                            variants = [
-                                EnumVariant(reference = Identifier),
-                                EnumVariant(reference = AddressKeyword, enabled = From("0.6.0"))
-                            ]
                         )
                     ]
                 ),
@@ -4024,27 +4016,21 @@ language_v2_macros::compile!(Language(
                     lexical_context = Solidity,
                     items = [
                         // Since an identifier path can include the reserved keyword `address` as parth of the path
-                        // (but not as the head), we differentiate between head (any `Identifier`)
-                        // and tail (which can use `MemberAccessIdentifier`)
-                        Struct(
-                            name = IdentifierPath,
-                            fields = (
-                                head = Required(Identifier),
-                                tail = Optional(reference = IdentifierPathTail)
-                            )
-                        ),
-                        Struct(
-                            name = IdentifierPathTail,
-                            fields = (
-                                sep = Required(Period),
-                                elements = Required(IdentifierPathTailElements)
-                            )
-                        ),
+                        // we use `IdentifierPathElement` to represent each element, instead of `Identifier`.
                         Separated(
-                            name = IdentifierPathTailElements,
-                            reference = MemberAccessIdentifier,
+                            name = IdentifierPath,
+                            reference = IdentifierPathElement,
                             separator = Period
                         ),
+                        Enum(
+                            // An element of an identifier path can be either an identifier or the reserved `address` keyword
+                            // Note: This is also used on `MemberAccessExpression`
+                            name = IdentifierPathElement,
+                            variants = [
+                                EnumVariant(reference = Identifier),
+                                EnumVariant(reference = AddressKeyword, enabled = From("0.6.0"))
+                            ]
+                        ),
                         Token(
                             name = Identifier,
                             definitions = [TokenDefinition(Sequence([