A struct that holds compile time environment information.
The current environment can be accessed at any time as __ENV__
. Inside macros, the caller environment can be accessed as __CALLER__
.
An instance of Macro.Env
must not be modified by hand. If you need to create a custom environment to pass to Code.eval_quoted/3
, use the following trick:
def make_custom_env do
import SomeModule, only: [some_function: 2]
alias A.B.C
__ENV__
end
You may then call make_custom_env()
to get a struct with the desired imports and aliases included.
It contains the following fields:
module
- the current module name file
- the current file name as a binary line
- the current line as an integer function
- a tuple as {atom, integer}
, where the first element is the function name and the second its arity; returns nil
if not inside a function context
- the context of the environment; it can be nil
(default context), inside a guard or inside a match aliases
- a list of two-element tuples, where the first element is the aliased name and the second one the actual name requires
- the list of required modules functions
- a list of functions imported from each module macros
- a list of macros imported from each module macro_aliases
- a list of aliases defined inside the current macro context_modules
- a list of modules defined in the current context vars
- a list keeping all defined variables as {var, context}
export_vars
- a list keeping all variables to be exported in a construct (may be nil
) lexical_tracker
- PID of the lexical tracker which is responsible for keeping user info local
- the module to expand local functions to Returns whether the compilation environment is currently inside a guard
Returns whether the compilation environment is currently inside a match clause
Returns a keyword list containing the file and line information as keys
Returns the environment stacktrace
aliases() :: [{module, module}]
context() :: :match | :guard | nil
context_modules() :: [module]
export_vars() :: vars | nil
file() :: binary
functions() :: [{module, [name_arity]}]
lexical_tracker() :: pid
line() :: non_neg_integer
local() :: atom | nil
macro_aliases() :: [{module, {integer, module}}]
macros() :: [{module, [name_arity]}]
name_arity() :: {atom, arity}
requires() :: [module]
t() :: %Macro.Env{module: atom, file: file, line: line, function: name_arity | nil, context: context, requires: requires, aliases: aliases, functions: functions, macros: macros, macro_aliases: aliases, context_modules: context_modules, vars: vars, export_vars: export_vars, lexical_tracker: lexical_tracker, local: local}
vars() :: [{atom, atom | non_neg_integer}]
in_guard?(t) :: boolean
Returns whether the compilation environment is currently inside a guard.
in_match?(t) :: boolean
Returns whether the compilation environment is currently inside a match clause.
location(t) :: Keyword.t
Returns a keyword list containing the file and line information as keys.
stacktrace(t) :: list
Returns the environment stacktrace.
© 2012–2017 Plataformatec
Licensed under the Apache License, Version 2.0.
https://hexdocs.pm/elixir/1.3.3/Macro.Env.html