Appendix — Error Model

Status: informative summary for consolidated v1

Canonical topic owners: ../AEON-v1-compliance.md, ../AEOS-spec-v1.md

If this appendix conflicts with the canonical compliance or AEOS spec, those canonical documents win.

1. Existing Diagnostics

Existing prior-release diagnostics remain valid unless superseded in v1.

2. v1 Policy/Behavior Diagnostics (active)

Core/policy diagnostics retained from prior v1-era behavior summaries use legacy uppercase-style codes:

Code	Category	Phase	Trigger
`ATTRIBUTE_DEPTH_EXCEEDED`	PolicyError	policy enforcement	address-expression attribute selector depth exceeds active `max_attribute_depth`
`SEPARATOR_DEPTH_EXCEEDED`	PolicyError	parse/policy enforcement	separator-spec depth exceeds active `max_separator_depth`
`GENERIC_DEPTH_EXCEEDED`	PolicyError	parse/policy enforcement	nested generic type depth exceeds active `max_generic_depth`
`INVALID_SEPARATOR_CHAR`	SyntaxError	parse	forbidden or malformed separator char in separator spec
`INVALID_ESCAPE`	SyntaxError	lex/parse	malformed quoted escape, malformed Unicode escape, lone surrogate, or out-of-range code point
`UNTERMINATED_STRING`	SyntaxError	lex	quoted string crosses a raw newline or EOF before closing delimiter
`UNTYPED_TOGGLE_LITERAL`	ModeError	mode enforcement	strict toggle literal not typed as `toggle`
`UNTYPED_VALUE_IN_STRICT_MODE`	ModeError	mode enforcement	strict-mode value lacks required typing

AEOS validation diagnostics use lowercase snake case:

Code	Category	Phase	Trigger
`trailing_separator_delimiter`	PolicyWarning/Error	schema validation (optional)	optional AEOS policy: separator literal payload ends with declared separator

Reference implementation policy surfaces:

Runtime option: trailingSeparatorDelimiterPolicy (off|warn|error)
CLI bind flag: --trailing-separator-delimiter-policy <off|warn|error>

3. Separator-Literal Boundary Clarification

Separator literals do not define a raw escape layer. Outside quoted string segments, the payload ends when ordinary grammar or comment syntax resumes, and disallowed raw characters may surface downstream as SYNTAX_ERROR depending on token context. This behavior is deterministic and expected under v1 separator-literal boundary rules.

4. Determinism Requirements

Diagnostics MUST:

fail closed where specified by phase contract
include stable code and canonical path context when applicable
be deterministic under identical input and policy settings

For the Unicode and quoted-string boundaries clarified in Core v1:

malformed quoted escapes SHOULD surface as INVALID_ESCAPE;
malformed Unicode escapes, lone surrogate escapes, and out-of-range code

points SHOULD surface as INVALID_ESCAPE;

raw newlines inside non-backtick quoted strings SHOULD surface as

UNTERMINATED_STRING.

5. Phase Presentation

Human-facing diagnostics SHOULD present the pipeline phase as a readable label rather than as a bare numeric band.

Recommended plain-text form:

<Phase Label>: <message> [CODE] path=$.x span=1:1-1:4

Example:

Reference Validation: Self reference: '$.a' references itself [SELF_REFERENCE] path=$.a span=1:1-1:4

JSON diagnostics MAY additionally include:

phase when the producing phase is explicitly known
phaseLabel when a stable human-readable phase name is available

When both are present, code remains the stable machine-facing identifier and phaseLabel is presentation metadata.

6. Payload Expectations

When applicable, diagnostics should include:

offending path/type context
observed depth
active policy limit
source span (if available)