Ion (serialization format)
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Filename extension |
.ion |
---|---|
Internet media type | application/ion |
Developed by | Amazon |
Type of format | Data interchange |
Website | amzn |
Ion is a data serialization language developed by Amazon. It may be represented by either a human-readable text form or a compact binary form. The text form is a superset of JSON; thus, any valid JSON document is also a valid Ion document.
Data types[]
As a superset of JSON, Ion includes the following data types
null
: An empty valuebool
: Boolean valuesstring
: Unicode text literalslist
: Ordered heterogeneous collection of Ion valuesstruct
: Unordered collection of key/value pairs
The nebulous JSON 'number' type is strictly defined in Ion to be one of
int
: Signed integers of arbitrary sizefloat
: 64-bit IEEE binary-encoded floating point numbersdecimal
: Decimal-encoded real numbers of arbitrary precision
Ion adds these types:
timestamp
: Date/time/time zone moments of arbitrary precisionsymbol
: Unicode symbolic atoms (aka identifiers)blob
: Binary data of user-defined encodingclob
: Text data of user-defined encodingsexp
: Ordered collections of values with application-defined semantics
Each Ion type supports a null variant, indicating a lack of value while maintaining a strict type (e.g., null.int
, null.struct
).
The Ion format permits annotations to any value in the form of symbols. Such annotations may be used as metadata for otherwise opaque data (such as a blob).
Implementations[]
Examples[]
Sample document[]
// comments are allowed in Ion files using the double forward slash
{
key: "value", // key here is a symbol, it can also be a string as in JSON
nums: 1_000_000, // equivalent to 1000000, use of underscores with numbers is more readable
'A float value': -31415e-4, // key is a value that contains spaces
"An int value": null.int,
annotated: age::45, // age here is the annotation to number 45
lists : 'hw grades'::[80, 85, 90], // any symbol can be used as an annotation
many_annot: I::have::many::annotations::true, // annotations are not nested, but rather, a list of annotations
sexp: (this (is a [valid] "Ion") last::value 42) // Ion S-expressions,
blob_value: {{OiBTIKUgTyAASb8=}},
clob_value: {{"a b"}}
}
Uses[]
- Amazon's Quantum Ledger Database (QLDB) stores data in Ion documents.[1]
- PartiQL, an open source SQL-based query language also by Amazon, is built upon Ion. PartiQL supported queries are used by QLDB, S3Select.[2]
Tooling and extensions[]
- Ion Path Extractor API aims to combine the convenience of a DOM API with the speed of a streaming API.
- IDE support
- Jackson data format module for Ion
- Apache Hive SerDe for Ion
- Ion Schema
- Ion Hash defines an algorithm for constructing a hash for any Ion value.
References[]
External links[]
Categories:
- Data serialization formats
- Markup languages