Module parser 

Parser: Logos lexer, recursive-descent parser, grammar traits Rowan-based incremental parser for SysML v2

This module provides a lossless, incremental parser using:

• logos for fast lexing
• rowan for the CST (Concrete Syntax Tree)

This is the rust-analyzer approach: we build a lossless CST that preserves all whitespace and comments, then extract an AST layer on top.

Architecture

Source Text
    ↓
Lexer (logos) → Tokens with SyntaxKind
    ↓
Parser → GreenNode tree (immutable, cheap to clone)
    ↓
SyntaxNode (rowan) → CST with parent pointers
    ↓
AST layer → Typed wrappers over SyntaxNode
    ↓
HIR → Semantic model

Incremental Reparsing

When text changes, we:

1. Find the smallest subtree containing the change
2. Reparse only that subtree
3. Reuse unchanged green nodes (they’re immutable and cheap to share)

Re-exports

pub use ast::*;

Modules

ast

Typed AST wrappers over the untyped rowan CST.

grammar

Grammar modules for KerML and SysML parsing

keywords

Keyword definitions extracted from KerML and SysML grammars

Structs

GreenNode

Re-export rowan types for convenience Internal node in the immutable tree. It has other nodes and tokens as children.

Lexer

Lexer wrapping the logos-generated tokenizer

Parse

Parse result containing the green tree and any errors

SyntaxError

A syntax error with location and message

TextRange

Re-export rowan types for convenience A range in text, represented as a pair of TextSize.

TextSize

Re-export rowan types for convenience A measure of text length. Also, equivalently, an index into text.

Token

A token with its kind, text, and position

Enums

SyntaxKind

All syntax kinds (tokens and nodes) in SysML v2

SysMLLanguage

Language definition for Rowan

Functions

kind_to_name

Convert a SyntaxKind to a human-readable name for error messages.

parse_kerml

Parse KerML source code into a CST

parse_sysml

Parse SysML source code into a CST

Type Aliases

SyntaxElement

SyntaxNode

Type aliases for convenience

SyntaxToken