Consuming external software
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Languages support a variety of ways to reference and consume other software in the syntax of the language. In some cases this is importing the exported functionality of a library, package or module but some mechanisms are simpler text file include operations.
Import can be classified by level (module, package, class, procedure,...) and by syntax (directive name, attributes,...).
- File include
#include <filename>or#include "filename"– C preprocessor used in conjunction with C and C++ and other development tools
- File import
addpath(directory)– MATLAB [8]COPYfilename.– COBOL:-include("filename").– Prolog#include file="filename"– ASP#include <filename>or#include "filename"– AutoHotkey, AutoIt#import "filename"or#import <filename>– Objective-CImport["filename"]– Mathematica, Wolfram Languageinclude'filename'– Fortraninclude "filename";– PHPinclude [filename] programor#include [filename] program– Pick Basicinclude!("filename");– Rustload "filename"– Rubyload%filename– Red-
require('filename')– Lua require "filename";– Perl, PHPrequire"filename"– Rubysource(""filename"")– R@import("filename");– Zig
- Package import
#include filename– C, C++#[path = "filename"] mod altname;– Rust@import module;– Objective-C<<name– Mathematica, Wolfram Language:-use_module(module).– Prolog:from module import *– Pythonextern crate libname;– orextern crate libname as altname;ormod modname;– Rustlibrary("package")– R:IMPORT module– Oberonimport altname "package/name"– Go:import package.module;orimport altname = package.module;– Dimport Moduleorimport qualified Module as M– Haskellimport package.*– Java, MATLAB, Kotlinimport "modname";– JavaScriptimport altname from "modname";– JavaScriptimport packageorimport package._– Scalaimport module– Swiftimport module– V (Vlang)import module– Python-
require('modname')– Lua require"gem"– Rubyuse module– Fortran 90+use module, only : identifier– Fortran 90+use Module;– Perluse Module qw(import options);– Perluse Package.Name– Cobrauses unit– Pascalwith package– Ada@import("pkgname");– Zig
- Class import
from module import Class– Pythonimport package.class– Java, MATLAB, kotlinimport class from "modname";– JavaScriptimport {class} from "modname";– JavaScriptimport {class as altname} from "modname";– JavaScriptimport package.class– Scalaimport package.{ class1 => alternativeName, class2 }– Scalaimport package._– Scalause Namespace\ClassName;– PHPuse Namespace\ClassName as AliasName;– PHP
- Procedure/function import
from module import function– Pythonimport package.module : symbol;– Dimport package.module : altsymbolname = symbol;– Dimport Module (function)– Haskellimport function from "modname";– JavaScriptimport {function} from "modname";– JavaScriptimport {function as altname} from "modname";– JavaScriptimport package.function– MATLABimport package.class.function– Scalaimport package.class.{ function => alternativeName, otherFunction }– ScalauseModule('symbol');– Perluse function Namespace\function_name;– PHPuse Namespace\function_name as function_alias_name;– PHPuse module::submodule::symbol;– Rustuse module::submodule::{symbol1, symbol2};– Rustuse module::submodule::symbol as altname;– Rust
- Constant import
use const Namespace\CONST_NAME;– PHP
The above statements can also be classified by whether they are a syntactic convenience (allowing things to be referred to by a shorter name, but they can still be referred to by some fully qualified name without import), or whether they are actually required to access the code (without which it is impossible to access the code, even with fully qualified names).
- Syntactic convenience
- Required to access code
import altname "package/name"Goimport altname from "modname";JavaScriptimport modulePython
