json_float

awsJson special-float helpers.

The AWS JSON protocols (awsJson1_0, awsJson1_1, plus other JSON-family wire formats) encode IEEE 754 specials as JSON strings: "NaN", "Infinity", "-Infinity". Plain JSON numbers cover every finite float.

Why a wrapper type instead of raw Float: Erlang’s float() type cannot hold NaN or Infinity. 0.0/0.0 raises badarith; binary_to_term rejects the IEEE 754 NaN bit pattern with badarg; <<F/float>> bit-syntax matching refuses to bind such values. So a faithful representation of an awsJson Float field on the BEAM target requires an explicit sum type — there’s no way to pack NaN into an Erlang float. Rust’s f64 happens to support these natively, which is why aws-sdk-rust gets away with Option<f64>.

Matches aws-sdk-rust’s aws-smithy-types::Number::SpecialFloat — same three string spellings, same case-sensitivity.

Types

SmithyFloat

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Tagged float that can faithfully round-trip every IEEE 754 value reachable from JSON in the awsJson protocols.

Generated code uses this for any field whose Smithy shape is smithy.api#Float or smithy.api#Double. User construction:

FloatValue(1.5) NaN PosInfinity NegInfinity

pub type SmithyFloat {
  FloatValue(Float)
  NaN
  PosInfinity
  NegInfinity
}

Constructors

```
FloatValue(Float)
```
```
NaN
```
```
PosInfinity
```
```
NegInfinity
```

Values

decoder

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pub fn decoder() -> decode.Decoder(SmithyFloat)

Decoder for a SmithyFloat. Accepts plain JSON numbers and the three special-float strings.

encode

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pub fn encode(v: SmithyFloat) -> json.Json

Encode a SmithyFloat as a JSON value. Finite values become JSON numbers; the three IEEE 754 specials become JSON strings, matching the awsJson wire spec.