View Source Macro.Env (Elixir v1.12.0)
A struct that holds compile time environment information.
The current environment can be accessed at any time as
__ENV__/0
. Inside macros, the caller environment can be
accessed as __CALLER__/0
.
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:
aliases
- a list of two-element tuples, where the first element is the aliased name and the second one the actual namecontext
- the context of the environment; it can benil
(default context),:guard
(inside a guard) or:match
(inside a match)context_modules
- a list of modules defined in the current contextfile
- the current file name as a binaryfunction
- a tuple as{atom, integer}
, where the first element is the function name and the second its arity; returnsnil
if not inside a functionfunctions
- a list of functions imported from each moduleline
- the current line as an integermacro_aliases
- a list of aliases defined inside the current macromacros
- a list of macros imported from each modulemodule
- the current module namerequires
- the list of required modules
The following fields are private to Elixir's macro expansion mechanism and must not be accessed directly:
contextual_vars
current_vars
lexical_tracker
prematch_vars
tracers
unused_vars
The following fields are deprecated and must not be accessed or relied on:
vars
- a list keeping all defined variables as{var, context}
Link to this section Summary
Functions
Checks if a variable belongs to the environment.
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.
Returns a Macro.Env
in the match context.
Returns a list of variables in the current environment.
Link to this section Types
@type context() :: :match | :guard | nil
@type context_modules() :: [module()]
@type file() :: binary()
@type functions() :: [{module(), [name_arity()]}]
@type lexical_tracker() :: pid() | nil
@type line() :: non_neg_integer()
@type macros() :: [{module(), [name_arity()]}]
@type requires() :: [module()]
@type t() :: %Macro.Env{ aliases: aliases(), context: context(), context_modules: context_modules(), contextual_vars: contextual_vars(), current_vars: current_vars(), file: file(), function: name_arity() | nil, functions: functions(), lexical_tracker: lexical_tracker(), line: line(), macro_aliases: macro_aliases(), macros: macros(), module: module(), prematch_vars: prematch_vars(), unused_vars: unused_vars(), requires: requires(), tracers: tracers(), vars: vars() }
Link to this section Functions
Checks if a variable belongs to the environment.
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.
Returns a Macro.Env
in the match context.
Returns a list of variables in the current environment.
Each variable is identified by a tuple of two elements, where the first element is the variable name as an atom and the second element is its context, which may be an atom or an integer.