evalex

EvalEx (evalex v0.1.1)

EvalEx is a powerful expression evaluation library for Elixir, based on evalexpr using rustler.

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Types

evalex_any()
evalex_error()

Functions

eval(expression, context \\ %{})

Evaluates the given expression and returns the result.

precompile_expression(expression)

Precompiles the given expression.

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evalex_any()

@type evalex_any() :: number() | boolean() | String.t() | nil | [evalex_any()]
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evalex_error()

@type evalex_error() ::
  :wrong_operator_amount
  | :wrong_function_argument_amount
  | :expected_string
  | :expected_int
  | :expected_float
  | :expected_number
  | :expected_number_or_string
  | :expected_boolean
  | :expected_tuple
  | :exepcted_fixed_length_tuple
  | :expected_empty
  | :append_to_leaf_node
  | :precedence_violation
  | :variable_identifier_not_found
  | :function_identefier_not_found
  | :type_error
  | :wrong_type_combination
  | :unmatched_l_brace
  | :unmatched_r_brace
  | :missing_operator_outside_of_brace
  | :unmatched_partial_token
  | :addition_error
  | :subtraction_error
  | :negation_error
  | :multiplication_error
  | :division_error
  | :modulation_error
  | :invaild_regex
  | :context_not_mutable
  | :illegal_escape_sequence
  | :custom_message
  | :unknown

Link to this section Functions

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eval(expression, context \\ %{})

(since 0.1.0) 
@spec eval(String.t() | EvalEx.PrecompiledExpression.t(), map()) ::
  {:ok, evalex_any()} | {:error, {evalex_error(), String.t()}}

Evaluates the given expression and returns the result.

examples

 Examples 

iex> EvalEx.eval("1 + 1")
{:ok, 2}

iex> EvalEx.eval("a * b", %{"a" => 10, "b" => 10})
{:ok, 100}

iex> EvalEx.eval("a == b", %{"a" => "tonio", "b" => "wanda"})
{:ok, false}

iex> EvalEx.eval("a != b", %{"a" => "tonio", "b" => "wanda"})
{:ok, true}

iex> EvalEx.eval("len(a)", %{"a" => [1, 2, 3]})
{:ok, 3}

iex> EvalEx.eval("a + b", %{"a" => 10})
{:error,
{:variable_identifier_not_found,
"Variable identifier is not bound to anything by context: "b"."}}

iex> {:ok, precompiled_expression} = EvalEx.precompile_expression("1 + 1")
{:ok,
%EvalEx.PrecompiledExpression{
reference: #Reference<0.2278913865.304611331.189837>,
resource: #Reference<0.2278913865.304742403.189834>
}}

iex> EvalEx.eval(precompiled_expression)
{:ok, 2}
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precompile_expression(expression)

(since 0.1.1) 
@spec precompile_expression(String.t()) ::
  {:ok, EvalEx.PrecompiledExpression.t()}
  | {:error, {evalex_error(), String.t()}}

Precompiles the given expression.