Iteraptor.AST (iteraptor v1.15.0)

Iteraptor.AST module traverses AST, allowing map, reduce and family.

Summary

Functions

map(input, fun, opts \\ [])

Mapper for the AST.

reduce(input, acc, fun, opts \\ [])

Reduces the AST with an accumulator.

Functions

map(input, fun, opts \\ [])

@spec map(
  binary() | {atom(), list(), any()} | list(),
  (any(), any() -> any()),
  list()
) :: any()

Mapper for the AST.

Parameters

input: the AST to traverse
fun: the function to be called on the tree element
opts: the options to be passed to the iteration
- yield: :all | nil what to yield; default: nil for yielding values only.

Examples

iex> bindings = [a: 1, b: 2, c: 3]
...> ":math.sin(42 * a / (3.14 * b)) > c"
...> |> Iteraptor.AST.map(fn
...>      {var, _, val} when is_atom(val) -> bindings[var]
...>      any -> any
...>    end)
{:>, [line: 1],
  [
    {{:., [line: 1], [:math, :sin]}, [line: 1],
      [
        {:/, [line: 1],
        [
          {:*, [line: 1], [42, 1]},
          {:*, [line: 1], [3.14, 2]}
        ]}
      ]},
    3
  ]}

reduce(input, acc, fun, opts \\ [])

@spec reduce(
  binary() | {atom(), list(), any()} | list(),
  any(),
  (any(), any() -> any()),
  list()
) :: any()

Reduces the AST with an accumulator.

Parameters

input: the AST to traverse
acc: the accumulator
fun: the function to be called on the tree element
opts: the options to be passed to the iteration
- yield: :all | nil what to yield; default: nil for yielding values only.

Examples

iex> ":math.sin(42 * a / (3.14 * b)) > c"
...> |> Iteraptor.AST.reduce([], fn
...>      {var, _, val}, acc when is_atom(val) -> [var | acc]
...>      _, acc -> acc
...>    end)
...> |> Enum.reverse()
~w|a b c|a