Boxic.FEEL (boxic_feel v0.1.0)

Parses and evaluates FEEL expressions.

The public facade accepts FEEL source through parse/1 and evaluate/2, or an already parsed syntax tree through evaluate_ast/2.

Summary

Types

ast()

context()

Functions

evaluate(expression, context \\ %{})

Parses and evaluates a FEEL expression.

evaluate_ast(ast, context)

Evaluates an AST previously returned by parse/1.

evaluate_unary_test(test_expression, value, context \\ %{})

Evaluates a FEEL unary test against value.

parse(expression)

Parses a FEEL expression into Boxic's public AST representation.

Types

ast()

@type ast() ::
  {:literal, term()}
  | {:identifier, String.t()}
  | {:unary, atom(), ast()}
  | {:binary, atom(), ast(), ast()}
  | {:list, [ast()]}
  | {:context, [{String.t(), ast()}]}
  | {:path, ast(), String.t()}
  | {:filter, ast(), ast()}
  | {:range, boolean(), boolean(), ast(), ast()}
  | {:in, ast(), ast()}
  | {:unary_test, atom(), ast()}
  | {:unary_tests, [ast()]}
  | {:sequence, ast(), ast()}
  | {:if, ast(), ast(), ast()}
  | {:for, String.t(), ast(), ast()}
  | {:for, [{String.t(), ast()}], ast()}
  | {:quantifier, :some | :every, String.t(), ast(), ast()}
  | {:between, ast(), ast(), ast()}
  | {:instance_of, ast(), String.t()}
  | {:function, [String.t()], ast()}
  | {:call, ast(), [ast()]}

context()

@type context() :: %{optional(String.t()) => term()}

Functions

evaluate(expression, context \\ %{})

@spec evaluate(String.t(), context()) ::
  {:ok, term()} | {:error, Boxic.FEEL.Error.t()}

Parses and evaluates a FEEL expression.

iex> Boxic.FEEL.evaluate("price * quantity", %{
...>   "price" => Decimal.new("12.50"),
...>   "quantity" => Decimal.new("2")
...> })
{:ok, Decimal.new("25.00")}

evaluate_ast(ast, context)

@spec evaluate_ast(ast(), context()) :: {:ok, term()} | {:error, Boxic.FEEL.Error.t()}

Evaluates an AST previously returned by parse/1.

evaluate_unary_test(test_expression, value, context \\ %{})

@spec evaluate_unary_test(String.t(), term(), context()) ::
  {:ok, boolean()} | {:error, Boxic.FEEL.Error.t()}

Evaluates a FEEL unary test against value.

iex> Boxic.FEEL.evaluate_unary_test(">= 18", Decimal.new("21"))
{:ok, true}

parse(expression)

@spec parse(String.t()) :: {:ok, ast()} | {:error, Boxic.FEEL.Error.t()}

Parses a FEEL expression into Boxic's public AST representation.

iex> Boxic.FEEL.parse("1 + 2")
{:ok, {:binary, :plus, {:literal, Decimal.new("1")}, {:literal, Decimal.new("2")}}}