Elixir v1.9.2 Macro.Env View Source
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:
module
- the current module namefile
- the current file name as a binaryline
- the current line as an integerfunction
- a tuple as{atom, integer}
, where the first element is the function name and the second its arity; returnsnil
if not inside a functioncontext
- the context of the environment; it can benil
(default context),:guard
(inside a guard) or:match
(inside a match)aliases
- a list of two-element tuples, where the first element is the aliased name and the second one the actual namerequires
- the list of required modulesfunctions
- a list of functions imported from each modulemacros
- a list of macros imported from each modulemacro_aliases
- a list of aliases defined inside the current macrocontext_modules
- a list of modules defined in the current contextlexical_tracker
- PID of the lexical tracker which is responsible for keeping user info
The following fields pertain to variable handling and must not be accessed or
relied on. To get a list of all variables, see vars/1
:
current_vars
unused_vars
prematch_vars
contextual_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
Specs
Specs
context() :: :match | :guard | nil
Specs
context_modules() :: [module()]
Specs
file() :: binary()
Specs
functions() :: [{module(), [name_arity()]}]
Specs
lexical_tracker() :: pid() | nil
Specs
line() :: non_neg_integer()
Specs
Specs
macros() :: [{module(), [name_arity()]}]
Specs
Specs
requires() :: [module()]
Specs
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: macro_aliases(), context_modules: context_modules(), vars: vars(), unused_vars: unused_vars(), current_vars: current_vars(), prematch_vars: prematch_vars(), lexical_tracker: lexical_tracker(), contextual_vars: contextual_vars() }
Specs
Link to this section Functions
Specs
Checks if a variable belongs to the environment.
Specs
Returns whether the compilation environment is currently inside a guard.
Specs
Returns whether the compilation environment is currently inside a match clause.
Specs
Returns a keyword list containing the file and line information as keys.
Specs
Returns the environment stacktrace.
Specs
Returns a Macro.Env
in the match context.
Specs
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.