Architecture

Pydantic Model
    ↓
inspectors.inspect_model  → FieldDescriptor[]
    ↓
constraints.extract_constraints → Constraint IR (PatternSpec / markers)
    ↓
cache.ModelIRCache (optional) → ModelIR
    ↓
columns.resolve_column
    ↓
translators.TranslatorRegistry.translate
    ↓
Rule dictionary (+ diagnostics)

SQLRules is a pure compiler pipeline with two phases:

Phase 1 — static model IR

1. Inspect the Pydantic model and preserve field declaration order.

2. Extract supported constraints into a dialect-neutral IR.

3. Cache immutable ModelIR keyed by model class (optional).

Phase 2 — bind and translate

4. Resolve each constrained field to a SQLAlchemy column.

5. Translate each IR constraint into one SQLAlchemy expression.

6. Assemble expressions into dict[str, list[ColumnElement[bool]]].

The compiler never connects to a database, executes SQL, or renders SQL strings. See COMPILER.md and INTERNAL_API.md for module-level detail.