Add arrow_type parameter to Arg class

.beads/issues.jsonl

@@ -30,7 +30,7 @@
 {"id":"vgi-python-coi","title":"Update extract_argument_specs() to remove arg_types parameter","description":"In vgi/argument_spec.py:\n1. Remove arg_types parameter from function signature\n2. Update arrow_type resolution logic:\n   - Use arg.arrow_type if explicitly set\n   - Infer from Python type hint using PYTHON_TO_ARROW\n   - Handle TableInput/AnyArrow → pa.null()\n   - Warn and default to pa.null() for unknown types\n3. Import PYTHON_TO_ARROW from vgi.arguments","status":"open","priority":2,"issue_type":"task","created_at":"2026-01-05T15:44:38.141157-05:00","created_by":"rusty","updated_at":"2026-01-05T15:44:38.141157-05:00","dependencies":[{"issue_id":"vgi-python-coi","depends_on_id":"vgi-python-cvj","type":"blocks","created_at":"2026-01-05T15:45:13.831745-05:00","created_by":"rusty"},{"issue_id":"vgi-python-coi","depends_on_id":"vgi-python-dv0","type":"blocks","created_at":"2026-01-05T15:45:13.864608-05:00","created_by":"rusty"}]}
 {"id":"vgi-python-cvj","title":"Add PYTHON_TO_ARROW type mapping to vgi/arguments.py","description":"Add the Python→Arrow type mapping dict after imports:\n```python\nPYTHON_TO_ARROW: dict[type, pa.DataType] = {\n    int: pa.int64(),\n    str: pa.utf8(),\n    float: pa.float64(),\n    bool: pa.bool_(),\n    bytes: pa.binary(),\n}\n```\nExport in __all__.","status":"closed","priority":2,"issue_type":"task","created_at":"2026-01-05T15:44:37.900421-05:00","created_by":"rusty","updated_at":"2026-01-05T15:48:42.422086-05:00","closed_at":"2026-01-05T15:48:42.422086-05:00","close_reason":"PR #18 created"}
 {"id":"vgi-python-d73","title":"Create docs/argument-serialization.md","description":"## Overview\n\nCreate LLM-friendly documentation explaining the argument specification serialization format. This document should enable future implementors (human or AI) to understand how function argument signatures are serialized to Arrow schemas.\n\n## File Location\n\n`docs/argument-serialization.md`\n\n## Document Structure\n\n### Title and Purpose\n\nExplain that this document describes how VGI function argument specifications are serialized to Apache Arrow schemas for IPC transmission and DuckDB function registration.\n\n### Quick Reference\n\nA concise summary table showing:\n- Metadata keys and their meanings\n- Special type representations\n\n### Schema Format\n\nExplain the single-schema design:\n1. All arguments are fields in one Arrow schema\n2. Positional arguments come first, in order (field index = position index)\n3. Named arguments follow, marked with metadata\n4. Field name = Python attribute name (or argument key for named)\n5. Field type = exact Arrow type\n\n### Metadata Keys Reference\n\nComplete table of all metadata keys:\n\n| Key | Value | Description |\n|-----|-------|-------------|\n| `vgi_arg` | `named` | Field is a named argument, not positional. The field name is the argument key. |\n| `vgi_type` | `table` | Argument receives streaming table input (Arg[TableInput]). Arrow type is pa.null(). |\n| `vgi_type` | `any` | Argument accepts any Arrow type (Arg[AnyArrow]). Arrow type is pa.null(). |\n| `vgi_varargs` | `true` | Argument collects all remaining positional args. Arrow type is the element type. |\n\n### Special Type Handling\n\nExplain how special argument types are represented:\n\n#### TableInput\n- Arrow type: `pa.null()`\n- Metadata: `{b\"vgi_type\": b\"table\"}`\n- Meaning: This position receives streaming RecordBatches, not a scalar value\n\n#### AnyArrow\n- Arrow type: `pa.null()`\n- Metadata: `{b\"vgi_type\": b\"any\"}`\n- Meaning: Accepts any valid Arrow scalar type at runtime\n\n#### Varargs\n- Arrow type: The element type (e.g., `pa.int64()` for `Arg[int](..., varargs=True)`)\n- Metadata: `{b\"vgi_varargs\": b\"true\"}`\n- Meaning: Collects all remaining positional arguments from this position onwards\n\n### Examples\n\n#### Example 1: Simple Function\n\n```python\nclass MyFunction(TableInOutFunction):\n    count = Arg[int](0)           # Positional 0\n    name = Arg[str](1)            # Positional 1\n    verbose = Arg[bool](\"verbose\") # Named\n\n# Serializes to:\nschema = pa.schema([\n    pa.field(\"count\", pa.int64()),\n    pa.field(\"name\", pa.utf8()),\n    pa.field(\"verbose\", pa.bool_(), metadata={b\"vgi_arg\": b\"named\"}),\n])\n```\n\n#### Example 2: Function with Table Input\n\n```python\nclass TransformFunction(TableInOutFunction):\n    multiplier = Arg[float](0)\n    data = Arg[TableInput](1)\n\n# Serializes to:\nschema = pa.schema([\n    pa.field(\"multiplier\", pa.float64()),\n    pa.field(\"data\", pa.null(), metadata={b\"vgi_type\": b\"table\"}),\n])\n```\n\n#### Example 3: Function with Varargs\n\n```python\nclass SumFunction(TableInOutFunction):\n    columns = Arg[str](0, varargs=True)\n\n# Serializes to:\nschema = pa.schema([\n    pa.field(\"columns\", pa.utf8(), metadata={b\"vgi_varargs\": b\"true\"}),\n])\n```\n\n#### Example 4: Complex Function\n\n```python\nclass ComplexFunction(TableInOutFunction):\n    count = Arg[int](0)\n    data = Arg[TableInput](1)\n    extra = Arg[float](2, varargs=True)\n    format = Arg[str](\"format\")\n    threshold = Arg[AnyArrow](\"threshold\")\n\n# Serializes to:\nschema = pa.schema([\n    pa.field(\"count\", pa.int64()),\n    pa.field(\"data\", pa.null(), metadata={b\"vgi_type\": b\"table\"}),\n    pa.field(\"extra\", pa.float64(), metadata={b\"vgi_varargs\": b\"true\"}),\n    pa.field(\"format\", pa.utf8(), metadata={b\"vgi_arg\": b\"named\"}),\n    pa.field(\"threshold\", pa.null(), metadata={b\"vgi_arg\": b\"named\", b\"vgi_type\": b\"any\"}),\n])\n```\n\n### Serialization Code\n\nShow how to serialize and deserialize:\n\n```python\n# Serialize to bytes\nschema_bytes = schema.serialize().to_pybytes()\n\n# Deserialize from bytes\nschema = pa.ipc.read_schema(pa.py_buffer(schema_bytes))\n```\n\n### Parsing Algorithm\n\nExplain how to parse a schema back to argument specs:\n\n1. Initialize position_index = 0\n2. For each field in schema:\n   a. Check if field has `vgi_arg=named` metadata\n   b. If named: position = field.name (string)\n   c. If positional: position = position_index, then increment position_index\n   d. Check for `vgi_type` metadata (table or any)\n   e. Check for `vgi_varargs` metadata\n   f. Create ArgumentSpec with extracted info\n\n### Not Included\n\nExplicitly state what is NOT serialized:\n- Default values\n- Validation constraints (ge, le, choices, pattern)\n- Documentation strings\n\nThese are Python-side concerns handled by the Arg descriptor at runtime.","status":"closed","priority":2,"issue_type":"task","created_at":"2026-01-05T11:19:17.488877-05:00","created_by":"rusty","updated_at":"2026-01-05T11:33:29.168007-05:00","closed_at":"2026-01-05T11:33:29.168007-05:00","close_reason":"Created comprehensive LLM-friendly documentation","dependencies":[{"issue_id":"vgi-python-d73","depends_on_id":"vgi-python-8ra","type":"blocks","created_at":"2026-01-05T11:19:30.820384-05:00","created_by":"rusty"}]}
-{"id":"vgi-python-dv0","title":"Add arrow_type parameter to Arg class","description":"In vgi/arguments.py:\n1. Add 'arrow_type' to __slots__\n2. Add parameter: arrow_type: pa.DataType | None = None\n3. Store: self.arrow_type = arrow_type\n4. Update __repr__ to include arrow_type if set","status":"open","priority":2,"issue_type":"task","created_at":"2026-01-05T15:44:38.020395-05:00","created_by":"rusty","updated_at":"2026-01-05T15:44:38.020395-05:00","dependencies":[{"issue_id":"vgi-python-dv0","depends_on_id":"vgi-python-cvj","type":"blocks","created_at":"2026-01-05T15:45:13.696822-05:00","created_by":"rusty"}]}
+{"id":"vgi-python-dv0","title":"Add arrow_type parameter to Arg class","description":"In vgi/arguments.py:\n1. Add 'arrow_type' to __slots__\n2. Add parameter: arrow_type: pa.DataType | None = None\n3. Store: self.arrow_type = arrow_type\n4. Update __repr__ to include arrow_type if set","status":"closed","priority":2,"issue_type":"task","created_at":"2026-01-05T15:44:38.020395-05:00","created_by":"rusty","updated_at":"2026-01-05T15:50:51.513273-05:00","closed_at":"2026-01-05T15:50:51.513273-05:00","close_reason":"PR #19 created","dependencies":[{"issue_id":"vgi-python-dv0","depends_on_id":"vgi-python-cvj","type":"blocks","created_at":"2026-01-05T15:45:13.696822-05:00","created_by":"rusty"}]}
 {"id":"vgi-python-dvo","title":"Export AnyValue in vgi/__init__.py","description":"Import and add AnyValue to __all__ exports","status":"closed","priority":2,"issue_type":"task","created_at":"2026-01-05T10:41:41.65732-05:00","created_by":"rusty","updated_at":"2026-01-05T11:07:09.187969-05:00","closed_at":"2026-01-05T11:07:09.187969-05:00","close_reason":"Exported AnyArrow in vgi/__init__.py","dependencies":[{"issue_id":"vgi-python-dvo","depends_on_id":"vgi-python-ckg","type":"blocks","created_at":"2026-01-05T10:41:48.715634-05:00","created_by":"rusty"}]}
 {"id":"vgi-python-e37","title":"move Invocation from function.py out to own file","description":"The Invocation clas is kind of seperate from functions, so it should be in its own file.  Move it and all of its other associated classes like InvocationType to its own file","status":"closed","priority":2,"issue_type":"task","created_at":"2026-01-04T09:18:46.605941-05:00","created_by":"rusty","updated_at":"2026-01-04T09:24:37.922675-05:00","closed_at":"2026-01-04T09:24:37.922675-05:00","close_reason":"Closed"}
 {"id":"vgi-python-e9q","title":"Unify ProtocolOutput classes with shared base","description":"ProtocolOutput classes in table_function.py:177-224 and table_in_out_function.py:144-207 share similar metadata() method and from_process_result() classmethod. The table_in_out version adds status field. Create shared base with table_in_out extending it for status support.","status":"closed","priority":3,"issue_type":"task","created_at":"2026-01-04T20:06:41.45014-05:00","created_by":"rusty","updated_at":"2026-01-04T21:54:55.871986-05:00","closed_at":"2026-01-04T21:54:55.871986-05:00","close_reason":"Not warranted - dataclass inheritance with slots=True doesn't allow adding required field (status) between inherited fields. The classes have different semantics (table_in_out requires status for generator state tracking) making inheritance impractical."}

vgi/arguments.py

@@ -543,6 +543,7 @@ def transform(self, batch):
         "choices",
         "pattern",
         "varargs",
+        "arrow_type",
         "_name",
         "_compiled_pattern",
     )
@@ -560,6 +561,7 @@ def __init__(
         choices: Sequence[ArgT] | None = None,
         pattern: str | None = None,
         varargs: bool = False,
+        arrow_type: pa.DataType | None = None,
     ) -> None:
         """Initialize an Arg descriptor with optional validation.
 
@@ -576,6 +578,8 @@ def __init__(
             varargs: If True, collect all remaining positional arguments from this
                 position onwards. Returns tuple[ArgT, ...]. Requires at least 1 value.
                 Must be positional (not named).
+            arrow_type: Explicit Arrow type for this argument. If not provided,
+                type is inferred from the type hint using PYTHON_TO_ARROW.
 
         Raises:
             ValueError: If conflicting constraints are specified (e.g., ge and gt).
@@ -609,6 +613,7 @@ def __init__(
         self.choices = choices
         self.pattern = pattern
         self.varargs = varargs
+        self.arrow_type = arrow_type
         self._name: str | None = None
         self._compiled_pattern: re.Pattern[str] | None = None
 
@@ -943,5 +948,7 @@ def __repr__(self) -> str:
             parts.append(f"pattern={self.pattern!r}")
         if self.varargs:
             parts.append("varargs=True")
+        if self.arrow_type is not None:
+            parts.append(f"arrow_type={self.arrow_type!r}")
 
         return f"Arg({', '.join(parts)})"