# `A2UICore.Coerce`
[🔗](https://github.com/a2ui-elixir/a2ui/blob/v0.1.1/umbrella/apps/a2ui_core/lib/a2ui_core/coerce.ex#L1)

Value coercions shared by the catalog functions: truthiness, text and
number conversion.

The rules follow the reference engines so that a function evaluates to
the same result everywhere:

  * `truthy?/1` is Python's `bool()`: `nil`, `false`, `0`, `0.0`, `""`,
    `[]` and `%{}` are falsy, everything else is truthy.
  * `to_string/1` renders a value the way `formatString` interpolates it:
    `nil` is empty, booleans are `true`/`false`, objects and arrays are
    compact JSON, numbers use the shortest round-trip form.
  * `to_float/1` and `to_integer/1` accept numbers, booleans and numeric
    strings. The BEAM has no infinity or NaN, so `"inf"` and `"nan"`
    are not numbers here.

## Examples

    iex> A2UICore.Coerce.truthy?(%{})
    false
    iex> A2UICore.Coerce.to_string([1, "a"])
    "[1,\"a\"]"
    iex> A2UICore.Coerce.to_float(" 42.5 ")
    {:ok, 42.5}

# `decompose`
*since 0.1.0* 

```elixir
@spec decompose(float()) :: {String.t(), non_neg_integer(), integer()}
```

Splits a float into `{sign, coefficient, exponent}` with
`value = ±coefficient × 10^exponent` using its shortest round-trip
decimal representation. `sign` is `"-"` or `""` (negative zero keeps
its sign).

# `float_to_string`
*since 0.1.0* 

```elixir
@spec float_to_string(float()) :: String.t()
```

Python's `repr` of a float: the shortest round-trip digits, `1e+16`
style exponents from `1e16`, and plain notation down to `1e-4`.

# `to_float`
*since 0.1.0* 

```elixir
@spec to_float(term()) :: {:ok, float()} | :error
```

Converts a value to a float, as Python's `float()` does.

Returns `:error` for `nil`, containers and non-numeric strings.

# `to_integer`
*since 0.1.0* 

```elixir
@spec to_integer(term()) :: {:ok, integer()} | :error
```

Converts a value to an integer, as Python's `int()` does: floats
truncate toward zero, booleans are 0/1, strings must be integer
literals.

# `to_string`
*since 0.1.0* 

```elixir
@spec to_string(term()) :: String.t()
```

Renders a value as interpolated text.

# `truthy?`
*since 0.1.0* 

```elixir
@spec truthy?(term()) :: boolean()
```

Python truthiness of a decoded JSON value.

---

*Consult [api-reference.md](api-reference.md) for complete listing*