FEATURE: Field and Index Access

Field	Value
Version	20220822 V1
Description	Define object field access, array and string indexing, optional access, and missing-value behavior.
Depends On	FEATURE-VALUE-001.md
Provides	field access, index access, optional access, negative indices, missing values
Consumes	ordered generator evaluator, jq value model

Programmatic Acceptance

=== AC value-002-conformance ===
Intent: The authoritative corpus cases exercising field and index access execute successfully.
Suite: scoped

import json import os import subprocess import sys

select = r"\.[A-Za-z]|\[[-0-9]" result = subprocess.run( [sys.executable, "sources/run_conformance.py", "--select", select, "--json"], capture_output=True, text=True, env={**os.environ, "JQ": f"{os.getcwd()}/jq"}, ) print(result.stdout) print(result.stderr, file=sys.stderr) report = json.loads(result.stdout) tally = report["summary"] assert sum(tally.values()) > 0 assert tally["fail"] == 0 and tally["error"] == 0 assert result.returncode == 0 === END AC value-002-conformance ===

User Acceptance

None.

Guardrails

Missing object fields produce null.
Optional access suppresses access errors without suppressing valid outputs.
Negative array indices follow jq's end-relative indexing semantics.