Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

https://github.com/omochi/CodegenKit

Swift code generation framework
https://github.com/omochi/CodegenKit

Last synced: 2 months ago
JSON representation

Swift code generation framework

Lists

README

        

# CodegenKit: Swift code generation framework

This is a framework for introducing code generation on your Swift project.
You can do meta-programming like below.

## Code becomes template as it is

Placeholders are defined by markers in Swift code as follows.

```swift
protocol TSDecl {}

extension TSDecl {
// @codegen(as)
// @end
}
```

Generated codes are inserted in area between markers.

Thus, CodegenKit doesn't use any specific template files.
Instead, Swift source codes are used as a template.

## Write code renderer in Swift

Write code renderer as follows.

```swift
import Foundation
import CodegenKit

struct Node {
var stem: String
var typeName: String
}

struct TSDeclRenderer: Renderer {
var nodes: [Node] = [...]

func isTarget(file: URL) -> Bool {
file.lastPathComponent == "TSDecl.swift"
}

func render(template: inout CodeTemplate, file: URL, on runner: CodegenRunner) throws {
template["as"] = asCasts()
}

func asCasts() -> String {
let lines: [String] = nodes.map { (node) in
"""
public var as\(node.stem.pascal): \(node.typeName)? { self as? \(node.typeName) }
"""
}
return lines.joined(separator: "\n")
}
}
```

Your source code are passed as `CodeTemplate` object.
You can edit contents of placeholder via subscript.

## Do code generation

After writing renderers, generate codes.
Perform code generation with following command.

```
$ swift package codegen
```

Previous code will be edited as follows.

```swift
// TSDecl.swift
protocol TSDecl {}

extension TSDecl {
// @codegen(as)
public var asClass: TSClassDecl? { self as? TSClassDecl }
public var asField: TSFieldDecl? { self as? TSFieldDecl }
public var asFunction: TSFunctionDecl? { self as? TSFunctionDecl }
public var asImport: TSImportDecl? { self as? TSImportDecl }
public var asInterface: TSInterfaceDecl? { self as? TSInterfaceDecl }
public var asMethod: TSMethodDecl? { self as? TSMethodDecl }
public var asNamespace: TSNamespaceDecl? { self as? TSNamespaceDecl }
public var asSourceFile: TSSourceFile? { self as? TSSourceFile }
public var asType: TSTypeDecl? { self as? TSTypeDecl }
public var asVar: TSVarDecl? { self as? TSVarDecl }
// @end
}
```

Let's start and enjoy code generation!
Please read [this document](Docs/init.md) for detailed setup instructions.

# Documents

- [Setup instructions](Docs/init.md)
- [CodeTemplateModule sublibrary](Docs/CodeTemplateModule.md)