Expand description
HawDB-owned PostgreSQL SQL/PGQ syntax frontend.
This crate owns tokens, byte spans, structured syntax errors, and syntax ASTs.
Statement envelopes use a bounded token PEG with packrat memoization, composed
SQL/PGQ rules, and transformation into the existing syntax AST. Expressions
and graph patterns are recognized by PEG rules.
Semantic binding and logical-plan lowering belong to hawdb-sql.
The internal PEG machinery is also reused by hawdb-cypher, with its own
lexer and PEG grammar; SQL tokenization rules do not apply to Cypher.
Database::query_sql* selects the relational PEG entry for SELECT and EXPLAIN
SELECT. Relational DDL/DML import the same PEG expression rules and lower
directly into HawDB IR. PGQ syntax acceptance
alone does not qualify a statement family for production execution.
The SQL/PGQ specification defines the compatibility contract. The implementation and routing checklist tracks the remaining parser/binder differential coverage, catalog durability, and shared query-pipeline qualification required before enabling production routing. Parser selection must be explicit by statement family, never a retry after another parser fails.
Structs§
- Create
Property Graph - Edge
Endpoint - Edge
Table Definition - Element
Exposure - Element
Label Exposure - Expression
Syntax - Graph
Edge Pattern Syntax - Graph
Element Pattern Syntax - Graph
Path Factor Syntax - Graph
Path Syntax - Graph
Pattern Quantifier - Graph
Pattern Syntax - Graph
Table - Graph
Table Column - Identifier
- Labeled
Expression Syntax - Lexer
Config - Locking
Clause Syntax - Order
BySyntax - Postgres
From Syntax - Postgres
Join Syntax - Postgres
Select Syntax - Qualified
Name - Relation
Table Syntax - Span
- Syntax
Error - Table
Alias - Table
Function Argument Syntax - Token
- Vertex
Table Definition
Enums§
- Binary
Operator Syntax - Element
Label - Expression
Kind Syntax - Graph
Edge Direction - Graph
Path Primary Syntax - Literal
Syntax - Lock
Strength Syntax - Null
Order Syntax - Order
Direction Syntax - PgqStatement
- Postgres
From Item Syntax - Postgres
Join Kind - Postgres
Statement Syntax - Property
Exposure - Relational
Statement Syntax - Syntax
Error Code - Token
Kind - Unary
Operator Syntax
Functions§
- first_
token - Reads only the first non-comment token for explicit statement-family dispatch. The rest of the input is validated by the selected parser. The full-input byte limit applies to complete tokenization, not to statement dispatch.
- parse_
graph_ table - parse_
pgq_ statement - parse_
postgres_ select - parse_
postgres_ statement - parse_
relational_ statement - Parses the executable relational SELECT and EXPLAIN SELECT families.
- tokenize
- tokenize_
with_ config