=== BEGIN ARTIFACT FEATURE-Type-And-Numeric-Primitives.md ===
# FEATURE: Type and Numeric Primitives

| Field       | Value |
|-------------|-------|
| Version     | 20260822 V1 |
| Description | Provides jq type inspection, numeric conversion, measurement, and mathematical primitives. |
| Depends On  | FEATURE-Value-Model.md, FEATURE-Field-And-Index-Access.md, FEATURE-Truthiness-And-Comparison.md |
| Provides    | type, length, utf8bytelength, tonumber, toboolean, numeric predicates, floor, sqrt, math primitives |
| Consumes    | jq values, comparison semantics |

## Questions

- None.

## Intent

Implement jq's type and numeric builtins using Python's standard library. Support type inspection, lengths, UTF-8 byte counts, numeric and boolean conversion, finite/NaN predicates, rounding, square roots, and the mathematical functions exercised by the corpus.

Numbers must preserve jq-compatible equality and serialization behavior, including NaN and infinities. Invalid input types and conversions raise jq runtime errors.

## Behavior

- `type` returns jq's six type names.
- `length` handles null, strings, arrays, objects, and numbers; booleans are invalid.
- `utf8bytelength` accepts strings and counts UTF-8 bytes.
- `tonumber` and `toboolean` preserve existing values and convert valid strings.
- Numeric predicates distinguish finite, infinite, NaN, and normal values.
- `floor`, `sqrt`, and required standard math functions follow jq numeric semantics.

## Programmatic Acceptance

=== AC value-004-conformance ===
Intent: The type and numeric primitive implementation passes every selected conformance case containing the owned numeric and type syntax.
Suite: scoped
Requires: executable=python3; scope=test

import json
import os
import subprocess
import sys

select = r"length|type|sqrt|floor|tonumber"
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 value-004-conformance ===

## User Acceptance

- None.

## Guardrails

- Use only Python standard-library facilities.
- Do not silently coerce invalid jq values.
- Preserve generator ordering and runtime error behavior.
=== END ARTIFACT ===
=== BEGIN ARTIFACT FEATURE-Arithmetic-And-Structural-Operators.md ===
# FEATURE: Arithmetic and Structural Operators

| Field       | Value |
|-------------|-------|
| Version     | 20260822 V1 |
| Description | Implements jq arithmetic, structural combination, repetition, splitting, and negation operators. |
| Depends On  | FEATURE-Type-And-Numeric-Primitives.md, FEATURE-Composition-And-Cartesian-Evaluation.md, FEATURE-Errors-And-Optional-Evaluation.md |
| Provides    | +, -, *, /, %, unary negation, recursive object merge, string repetition and splitting |
| Consumes    | jq value model, generator evaluation, comparison semantics |

## Questions

- None.

## Intent

Implement jq's typed arithmetic and structural operators. Operators evaluate both operands as filters over the same input and preserve Cartesian generator behavior.

## Behavior

- Numbers use jq-compatible arithmetic.
- Arrays concatenate with `+` and subtract matching elements with `-`.
- Strings concatenate with `+`, repeat with numeric `*`, and split with `/`.
- Objects merge with `+`; `*` recursively merges nested objects.
- `null` is additive with any value.
- Division and remainder by zero raise runtime errors.
- Unary negation accepts numbers only and preserves partial output semantics.

## Programmatic Acceptance

=== AC flow-001-conformance ===
Intent: The arithmetic and structural operator implementation passes every selected conformance case containing the owned operators.
Suite: scoped
Requires: executable=python3; scope=test

import json
import os
import subprocess
import sys

select = r"\+|\-|\*|/|%"
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 flow-001-conformance ===

## User Acceptance

- None.

## Guardrails

- Do not perform implicit cross-type conversions.
- Preserve operator precedence, generator multiplicity, and runtime errors.
- Do not shell out to another jq implementation.
=== END ARTIFACT ===
=== BEGIN ARTIFACT FEATURE-Boolean-And-Alternative-Operators.md ===
# FEATURE: Boolean and Alternative Operators

| Field       | Value |
|-------------|-------|
| Version     | 20260822 V1 |
| Description | Implements jq Boolean operators, truthiness-aware alternatives, and defined-or assignment. |
| Depends On  | FEATURE-Truthiness-And-Comparison.md, FEATURE-Arithmetic-And-Structural-Operators.md |
| Provides    | and, or, not, //, //= |
| Consumes    | jq truthiness, generator core, arithmetic operators |

## Questions

- None.

## Intent

Implement strict Boolean operators and jq's value-selection alternative operators. Boolean operators produce Boolean values, while `//` selects non-null and non-false generator outputs.

## Behavior

- Only `false` and `null` are falsey.
- `and`, `or`, and `not` produce Boolean results with generator-valued operands evaluated according to jq semantics.
- `a // b` emits all non-false, non-null values from `a`; otherwise it evaluates `b`.
- `//=` updates defined-or paths using jq assignment semantics.
- Short-circuiting must prevent unnecessary error-producing branches where jq requires it.

## Programmatic Acceptance

=== AC flow-002-conformance ===
Intent: The Boolean and alternative operator implementation passes every selected conformance case containing the owned operators.
Suite: scoped
Requires: executable=python3; scope=test

import json
import os
import subprocess
import sys

select = r"and|or|not|//"
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 flow-002-conformance ===

## User Acceptance

- None.

## Guardrails

- Do not treat empty strings, arrays, or objects as falsey.
- Preserve generator multiplicity and alternative fallback semantics.
- Do not evaluate fallback branches when jq semantics select the left stream.
=== END ARTIFACT ===
=== BEGIN ARTIFACT FEATURE-Conditionals-And-Exception-Flow.md ===
# FEATURE: Conditionals and Exception Flow

| Field       | Value |
|-------------|-------|
| Version     | 20260822 V1 |
| Description | Implements jq conditional branching, try/catch handling, and optional error suppression. |
| Depends On  | FEATURE-Errors-And-Optional-Evaluation.md, FEATURE-Truthiness-And-Comparison.md, FEATURE-Boolean-And-Alternative-Operators.md |
| Provides    | if/then/elif/else/end, try/catch, optional filter operator |
| Consumes    | jq truthiness, runtime error flow, generator evaluation |

## Questions

- None.

## Intent

Implement control flow over jq generator streams. Conditions may produce multiple values, and each truthy or falsey result selects its corresponding branch independently.

## Behavior

- `if A then B else C end` evaluates branches for each output of `A`.
- Missing `else` defaults to identity.
- `elif` chains preserve jq branch ordering and fallback behavior.
- `try EXP catch HANDLER` catches runtime errors and evaluates the handler with the error value.
- `try EXP` suppresses errors and produces no replacement output.
- `EXP?` is equivalent to `try EXP`.
- Outputs produced before an uncaught runtime error remain available to the process boundary.

## Programmatic Acceptance

=== AC flow-003-conformance ===
Intent: The conditional and exception-flow implementation passes every selected conformance case containing the owned syntax.
Suite: scoped
Requires: executable=python3; scope=test

import json
import os
import subprocess
import sys

select = r"if |try |\?"
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 flow-003-conformance ===

## User Acceptance

- None.

## Guardrails

- Preserve partial output before runtime failure.
- Catch only runtime errors within the protected expression.
- Keep compile failures distinct from runtime failures.
=== END ARTIFACT ===
=== BEGIN ARTIFACT FEATURE-Labels-And-Breaks.md ===
# FEATURE: Labels and Breaks

| Field       | Value |
|-------------|-------|
| Version     | 20260822 V1 |
| Description | Implements lexically scoped labels and generator termination through break expressions. |
| Depends On  | FEATURE-Declarations-And-Control-Syntax.md, FEATURE-Errors-And-Optional-Evaluation.md, FEATURE-Conditionals-And-Exception-Flow.md |
| Provides    | label, break |
| Consumes    | parsed declarations, runtime error flow, generator core |

## Questions

- None.

## Intent

Implement jq's lexical `label $name | ... break $name ...` control mechanism. A break terminates the matching enclosing generator and behaves as though that label expression produced `empty`.

## Behavior

- Labels bind only within their lexical body.
- `break $name` terminates the nearest visible matching label.
- Outputs produced before the break are retained in order.
- Breaks do not leak into unrelated generators or labels.
- A break without a visible label is rejected at compile time.
- Labels and breaks work inside iteration, reductions, conditionals, and nested pipelines.

## Programmatic Acceptance

=== AC flow-004-conformance ===
Intent: The labels and breaks implementation passes every selected conformance case containing label or break syntax.
Suite: scoped
Requires: executable=python3; scope=test

import json
import os
import subprocess
import sys

select = r"label|break"
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 flow-004-conformance ===

## User Acceptance

- None.

## Guardrails

- Enforce lexical visibility during compilation.
- Terminate only the matching label scope.
- Preserve outputs emitted before termination and generator ordering.
=== END ARTIFACT ===