View Source Recode.AST (Recode v0.7.2)
This module provides functions to get informations from the AST and to manipulate the AST.
Most of the functions in this module require an AST with additional
informations. This information is provided by Sourceror or
Code.string_to_quoted/2 with the options
[
columns: true,
literal_encoder: &{:ok, {:__block__, &2, [&1]}},
token_metadata: true,
unescape: false
]See also Formatting considerations
in the docs for Code.quoted_to_algebra/2.
This module provides literal? functions that are also work with encoded
literals generate by literal_encoder: %{:ok, {:__block__, &2, [&1]}}.
For an example see atom?/1.
Summary
Functions
Returns the infos from an AST representing an alias expression.
Concatinates the aliases of an :__aliases__ tuple.
Returns true if the given AST represents an atom.
Returns the line in which the given AST starts.
Returns the newlines value from meta[:end_of_expression], or nil.
Returns the value from a :__block__ with a single argument.
Returns a mfa-tuple for the given .-call.
Returns true when the given ast represents an expression that spans over
multiple lines.
Converts AST representing a name to a string.
Puts the given value newlines under the key nevlines in
meta[:end_of_expression].
Puts the given value in the :__block__ AST.
Update a function call.
Updates the function name of a capture.
Updates the AST representing a definition.
Update a dotted function call.
Updates a spec.
Functions
Returns the infos from an AST representing an alias expression.
The function returns 3-tuple containing the alias, the multi part and the
:as.
Examples
iex> ast = quote do
...> alias Foo.Bar
...> end
iex> alias_info(ast)
{Foo.Bar, [], nil}
iex> ast = quote do
...> alias Foo.{Bar, Baz}
...> end
iex> alias_info(ast)
{Foo, [Bar, Baz], nil}
iex> ast = quote do
...> alias Foo, as: Baz
...> end
iex> alias_info(ast)
{Foo, [], Baz}
iex> ast = Sourceror.parse_string!("alias __MODULE__")
iex> alias_info(ast)
{:__MODULE__, [], nil}
iex> ast = Sourceror.parse_string!("alias __MODULE__.{Foo, Bar.Baz}")
iex> alias_info(ast)
{:__MODULE__, [Foo, Bar.Baz], nil}
iex> ast = Sourceror.parse_string!("alias __MODULE__, as: MyModule")
iex> alias_info(ast)
{:__MODULE__, [], MyModule}@spec aliases_concat({:__aliases__, Macro.metadata(), [atom()]}) :: module()
Concatinates the aliases of an :__aliases__ tuple.
Examples
iex> aliases_concat({:__aliases__, [], [:Alpha, :Bravo]})
Alpha.BravoReturns true if the given AST represents an atom.
Examples
iex> ":atom" |> Code.string_to_quoted!() |> atom?()
true
iex> ":atom" |> Sourceror.parse_string!() |> atom?()
true
iex> "42" |> Sourceror.parse_string!() |> atom?()
false
iex> ast = Code.string_to_quoted!(
...> ":a", literal_encoder: &{:ok, {:__block__, &2, [&1]}})
{:__block__, [line: 1], [:a]}
iex> atom?(ast)
trueReturns the line in which the given AST starts.
Note: The AST must be constructed by Sourceror or with the Code module and
the options columns: true, token_metadata: true.
Examples
iex> code = """
...> 1 +
...> 2 -
...> 3
...> """
iex> code |> Sourceror.parse_string!() |> first_line()
1
iex> code |> Sourceror.parse_string!() |> last_line()
3
iex> code
...> |> Code.string_to_quoted!(
...> columns: true,
...> token_metadata: true,
...> literal_encoder: &{:ok, {:__block__, &2, [&1]}})
...> |> last_line()
3Returns the newlines value from meta[:end_of_expression], or nil.
Returns the value from a :__block__ with a single argument.
Examples
iex> "[1, 2]"
...> |> Sourceror.parse_string!()
...> |> get_value()
...> |> Enum.map(&get_value/1)
[1, 2]@spec mfa({{:., keyword(), list()}, Macro.metadata(), Macro.t()}) :: {module(), atom(), non_neg_integer()}
Returns a mfa-tuple for the given .-call.
@spec multiline?(Macro.t() | Macro.metadata()) :: boolean()
Returns true when the given ast represents an expression that spans over
multiple lines.
multiline? does not pay attention to do blocks.
Examples
iex> """
...> def foo(x)
...> when is_integer(x) do
...> {:foo, x}
...> end
...> """
...> |> Sourceror.parse_string!() |> multiline?()
true
iex> """
...> def foo(x) when is_integer(x) do
...> {:foo, x}
...> end
...> """
...> |> Sourceror.parse_string!() |> multiline?()
false
iex> """
...> {
...> x,
...> y
...> }
...> """
...> |> Sourceror.parse_string!() |> multiline?()
true
iex> """
...> {x, y}
...> """
...> |> Sourceror.parse_string!() |> multiline?()
falseConverts AST representing a name to a string.
This function suppresses the prefix "Elixir.".
Examples
iex> name([Recode, AST])
"Recode.AST"
iex> name(Recode.AST)
"Recode.AST"Puts the given value newlines under the key nevlines in
meta[:end_of_expression].
Puts the given value in the :__block__ AST.
Examples
iex> "[1, 2]"
...> |> Sourceror.parse_string!()
...> |> get_value()
...> |> Enum.map(fn ast -> put_value(ast, "0") end)
...> |> Enum.map(&get_value/1)
["0", "0"]Update a function call.
The keyword list updates can have the keys name, meta and args.
Examples
iex> quote do
...> foo(x)
...> end
...> |> update_call(name: :bar)
...> |> Macro.to_string()
"bar(x)"Updates the function name of a capture.
Updates the AST representing a definition.
The keyword list updates can have the keys name, meta and args.
Examples
iex> ast = Sourceror.parse_string!("def foo(x), do: x")
iex> ast |> update_definition(name: :bar) |> Macro.to_string()
"def bar(x), do: x"
iex> ast |> update_definition(args: [{:y, [], nil}]) |> Macro.to_string()
"def foo(y), do: x"Update a dotted function call.
Examples
iex> ast = quote do
...> Foo.foo(x)
...> end
iex> update_dot_call(ast, name: :bar)
{{:., [], [{:__aliases__, [alias: false], [:Foo]}, :bar]}, [], [{:x, [], Recode.ASTTest}]}Updates a spec.
The keyword list updates can have the keys name, meta, args and
return.
Examples
iex> quote do
...> @spec foo(integer()) :: integer()
...> end
...> |> update_spec(name: :bar, return: {:term, [], []})
...> |> Macro.to_string()
"@spec bar(integer()) :: term()"