Swift REPL: how to import, load, evaluate, or requ

2019-01-14 20:47发布

问题:

In the Swift REPL, how to import (a.k.a. load, evaluate, require) a typical text *.swift file?

  • I want to use the code from this file: ~/src/Foo.swift

  • Syntax like this doesn't work: import ~/src/Foo.swift

For comparison:

  • An equivalent solution in the Swift REPL for a framework is: import Foundation

  • An equivalent solution in the Ruby REPL for a *.ruby file is: require "~/src/foo"

These are similar questions that are /not/ what I'm asking:

  • How to use/make a Swift command-line script, executable, module, etc.

  • How to use/make an XCode playground, project, library, framework, etc.

  • How to launch the REPL with a pre-existing list of files.

回答1:

You need to use -I, so if your modulename.swiftmodule file is in ~/mymodules than launch swift with

swift -I ~/mymodules

and then you will be able to import your module

import module name

Should be that easy



回答2:

In swift,you can't import a typical *.swift file.

For Import Declaration can only be the following syntax:

“ ‌ import-declaration → attributesopt import import-kindopt import-path
import-kind → typealias| struct| class| enum| protocol| var| func
‌ import-path → import-path-identifier| import-path-identifier.import-path
‌ import-path-identifier → identifier| operator”

From: Apple Inc. “The Swift Programming Language (Swift 2)”。 iBooks.

which can be described as these formats:

import module
import import kind module.symbol name
import module.submodule

import head.swift is incompatible with import import-kind module.symbol-name


Usually compile the files you want to import as a framework.Then it can be regarded as a module. use -F framework_directory/ to specify 3rd-party frameworks' search path.

  1. Create a file. For example:

    // test.swift import headtest print("Hello World")

  2. open your terminal

  3. goto the directory where you create the file.
  4. execute command line

    swift -F headtest test.swift

And done.



回答3:

Simply insert the shebang line at the top of your script:

#!/usr/bin/env xcrun swift


回答4:

It looks like it's not possible to import file and get Xcode to use REPL for it using specifications you gave. I think you can still do it creating a proper framework, but it's not exactly what you was looking.



回答5:

You can copy/paste the source code into the repl and execute it. Not ideal, obviously, but sometimes useful.