https://github.com/omochi/CodegenKit

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

Last synced: 3 months ago
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Swift code generation framework

• Host: GitHub
• URL: https://github.com/omochi/CodegenKit
• Owner: omochi
• License: mit
• Created: 2022-12-15T18:23:09.000Z (almost 2 years ago)
• Default Branch: main
• Last Pushed: 2024-04-01T03:05:43.000Z (8 months ago)
• Last Synced: 2024-04-01T04:23:21.176Z (8 months ago)
• Language: Swift
• Homepage:
• Size: 59.6 KB
• Stars: 14
• Watchers: 1
• Forks: 1
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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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)