# AEON GP Measurement v1 Convention identifier: `aeon.gp.measurement.v1` --- ## 1. Purpose `aeon.gp.measurement.v1` defines a lightweight measurement-label convention built on AEON core syntax. It standardizes a small set of descriptive labels for: - measurement units - measurement systems or standards - representational or measurement precision - currency denominations This convention does **not** extend AEON core semantics. It relies on existing AEON constructs: - attributes (`@{}`) - ordinary scalar values --- ## 2. Design Goals The measurement convention aims to be: - minimal - predictable - non-computational - cross-domain - easy to validate downstream It provides measurement interoperability without turning AEON into a unit-conversion language. --- ## 3. Non-Goals `aeon.gp.measurement.v1` does **not require AEON core** to: - convert units - normalize numeric values - infer measurement systems - compute derived values - perform exchange-rate logic Examples: ```aeon distance@{unit="m"} = 3 price@{currency="AUD"} = 19.95 ``` These statements only label the data. Any computation or interpretation belongs to: - schemas - profiles - processors - application logic --- ## 4. Core Principle A measurement convention defines interpretation agreements, not language semantics. AEON core preserves: - bindings - attributes - scalar values The convention defines how these preserved patterns are commonly understood by cooperating consumers. --- ## 5. Reserved Measurement Keys The following lowercase attribute keys have defined meaning under `aeon.gp.measurement.v1`. Attribute keys defined by this convention **must be lowercase ASCII identifiers**. Unknown keys remain allowed and are treated as opaque unless defined elsewhere. | Key | Purpose | | :--- | :--- | | `unit` | measurement unit label | | `system` | measurement system or standard context | | `precision` | representational or measurement resolution | | `currency` | monetary denomination | *Reserved measurement keys* --- ### 5.1 `unit` Declares a measurement unit label associated with a value. ```aeon distance@{unit="m"} = 3 weight@{unit="kg"} = 82 temperature@{unit="C"} = 21 ``` Meaning: - identifies the unit of measurement - purely descriptive - does not imply conversion or calculation --- ### 5.2 `system` Declares the system or standard context in which a unit or label should be interpreted. ```aeon mass@{unit="oz", system="avoirdupois"} = 12 volume@{unit="oz", system="US-fluid"} = 8 distance@{unit="mile", system="imperial"} = 3 length@{unit="m", system="metric"} = 10 ``` Meaning: - disambiguates unit systems - provides contextual classification - does not imply conversion behavior --- ### 5.3 `precision` Declares the intended representational or measurement resolution of a value. ```aeon length@{unit="mm", precision=0.1} = 125.4 temperature@{unit="C", precision=0.01} = 21.37 price@{currency="AUD", precision=0.01} = 19.95 ``` Meaning: - indicates expected granularity or accuracy - does not require rounding or formatting --- ### 5.4 `currency` Declares a currency denomination associated with a numeric value. ```aeon price@{currency="AUD"} = 19.95 budget@{currency="EUR"} = 500 ``` Meaning: - identifies monetary denomination - does not imply exchange-rate logic or accounting rules --- ## 6. Unknown Keys The measurement convention permits extension. Rule: - known reserved keys have stable meaning - unknown keys may appear - unknown keys should be treated as opaque unless a schema, profile, or another convention defines them This enables forward compatibility. --- ## 7. Validation Posture `aeon.gp.measurement.v1` itself is descriptive. Validation belongs to downstream layers. Examples: A schema might require: - `currency` to match ISO codes - `unit` to match an allowed list - `precision` to match allowed increments These checks are **not AEON core responsibilities**. --- ## 8. Example Document ```aeon aeon:header = { convention = "aeon.gp.measurement.v1" } distance@{unit="m", system="metric", precision=0.01} = 3 price@{currency="AUD", precision=0.01} = 19.95 mass@{unit="oz", system="avoirdupois"} = 12 ``` --- ## 9. Interpretation Summary | Pattern | Meaning | | :--- | :--- | | `@{unit="m"}` | measurement unit label | | `@{system="metric"}` | measurement system context | | `@{precision=0.01}` | representational resolution | | `@{currency="AUD"}` | monetary denomination | *Measurement interpretation patterns* --- ## 10. Definition `aeon.gp.measurement.v1` is a versioned interoperability convention that standardizes common measurement labels using AEON core constructs, without extending AEON core semantics. --- ## Related documents - [AEON Conventions Overview](./aeon-conventions-overview.md) - [Appendix — Informative Reference: Measurement Labels](./measurement-reference.md) - [Appendix — Compound Unit Labels (Informative)](./compound-unit-labels.md)