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

[JMESPath](https://jmespath.org/specification.html) queries over JSON
data: the engine behind the MCP catalog's `jmespath` function.

It implements the specification — field and index access, slices,
list, object, flatten and filter projections, multi-select lists and
hashes, pipes, `||`, `&&`, `!`, comparisons, literals, raw strings,
expression references and every built-in function — and agrees with
the JMESPath compliance suite.

    iex> A2UICore.JMESPath.search("people[?age > `30`].name", %{
    ...>   "people" => [%{"name" => "Ada", "age" => 36}, %{"name" => "Alan", "age" => 29}]
    ...> })
    {:ok, ["Ada"]}
    iex> A2UICore.JMESPath.search("sort_by(items, &price)[0].id", %{
    ...>   "items" => [%{"id" => "b", "price" => 3}, %{"id" => "a", "price" => 1}]
    ...> })
    {:ok, "a"}

A malformed expression, a function called with the wrong number or
types of arguments, and an unknown function are errors with category
`:expression` and the codes `JMESPATH_SYNTAX`, `JMESPATH_INVALID_ARITY`,
`JMESPATH_INVALID_TYPE`, `JMESPATH_INVALID_VALUE` and
`JMESPATH_UNKNOWN_FUNCTION`.

    iex> {:error, error} = A2UICore.JMESPath.search("foo[", %{})
    iex> error.code
    "JMESPATH_SYNTAX"

JSON objects are Elixir maps, so `keys/1` and `values/1` return their
entries in map order; the specification leaves that order open.

# `search`
*since 0.1.0* 

```elixir
@spec search(String.t(), term()) :: {:ok, term()} | {:error, A2UICore.Error.t()}
```

Evaluates `expression` against `data`.

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