Inclusion

LFE supports including header files and library files, which is essential for larger projects and when working with Erlang/OTP libraries.

include-lib

The include-lib directive allows you to include files from installed OTP applications or other libraries:

(include-lib "kernel/include/file.hrl")
(include-lib "stdlib/include/qlc.hrl")

This searches for the include file in the standard library locations and makes the definitions available in your code.

include-file

The include-file directive includes files using relative or absolute paths:

(include-file "local-definitions.lfe")
(include-file "../shared/common.lfe")
(include-file "/absolute/path/to/file.lfe")

Include File Content

Include files typically contain:

• Record definitions
• Macro definitions
• Constant definitions
• Type specifications

Example include file (records.lfe):

(defrecord person
  name
  age
  email)

(defmacro debug (msg)
  `(io:format "DEBUG: ~p~n" (list ,msg)))

After including this file, you can use the record and macro definitions in your code:

lfe> (include-file "records.lfe")
debug

;; In LFE, when including a file in the REPL, the last
;; function defined in the file is printed to stdout.

lfe> (make-person name "Robert" age 54 email "robert@lfe.io")
#(person "Robert" 54 "robert@lfe.io")
lfe>

lfe> (debug "oops")
DEBUG: "oops"
ok