FEATURE: String Manipulation Builtins

Field	Value
Version	20260822 V1
Description	Provide jq string trimming, conversion, splitting, joining, and prefix operations.
Depends On	ARCHITECTURE.md, FEATURE-DATA-004.md
Provides	trim, ltrim, rtrim, ltrimstr, rtrimstr, trimstr, ascii_downcase, ascii_upcase, explode, implode, split, join, startswith, endswith
Consumes	jq string values, generator evaluator

Workflow

Implement Unicode-aware whitespace trimming, prefix and suffix removal, ASCII-only case conversion, Unicode codepoint conversion, string splitting and joining, and prefix/suffix predicates. Validate input types and preserve jq's stream and error behavior.

Programmatic Acceptance

=== AC text-001-conformance ===
Intent: The string manipulation slice executes matching corpus cases and passes all selected cases.
Suite: scoped
Requires: executable=python3; scope=test

import json import os import subprocess import sys

select = r"split|join|trim|ascii_|explode|implode|startswith|endswith" 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) summary = report["summary"] assert sum(summary.values()) > 0 assert summary["fail"] == 0 assert summary["error"] == 0 assert result.returncode == 0 === END AC text-001-conformance ===

User Acceptance

None.

Guardrails

String length and codepoint operations must support Unicode values without treating UTF-8 bytes as individual characters.
ascii_downcase and ascii_upcase must affect only ASCII letters.
Invalid argument types must produce jq runtime errors rather than silent coercions.