UnGen

Flipping code generators on its head.

Design Principles

Prototype First (no custom generator code)
Works in any programming language
Simple and human-readable DSL

How to Use the CLI

Easiest way is to use the docker image, "howlowck/ungen". You can also download the executible for your OS.

There are a few options associated with the tool, you can run ungen to see the text, but here is the output below:

-i string
    InputDirectory (Required)
-o string
    OutputDirectory (Required)
-keep
    Keep the UNGEN line
-zip
    Zip the output directory into a file
-var value
    Set Variables (ex. -var foo=bar -var baz=qux)

You can set -var option multiple times (just like Terraform var flags)

Writing UNGEN commands

Ungen is meant to be human readable and simple to use, but it is a programming language.

To create a Ungen command, you just have to tag your line comments with "UNGEN:" (just like you would with TODO:) in any code you are writing. Like so:

// UNGEN: replace "World" with kebabCase(var.appName)
app.get('/', (req, res) => res.send('Hello World!'));

The command above will replace all occurance of "World" with the kebab-case form of the value of the appName variable.

Language Features:

if / then / else - conditionals. else is optional
copy or cut - "clipboard" operations
"hello" - string literals are in double quotes. This would be a value of a string Hello.
var.<variable-name> - variable values are prefix with var.
camelCase(<value>) - string functions are called like so, and will return a string value.

Operations (more to come)

Copy or Cut into the Clipboard

Specify the next x number of lines (next 2 lines) or line number (ln 2) or line number range (ln 3-6), then specify the name of the clipboard value (cb.myText)

Example: // UNGEN: copy next 1 line to cb.myText it will store the next line into the myText cb value.

String Replace

Looks at the next line, and replace any string value to another value.

Example: // UNGEN: replace "World" with var.appName

String Delete

Delete the n number of lines.

Example: // UNGEN: delete 2 lines

File Delete

Delete the current file.

Example: // UNGEN: delete file

Directory Delete

Delete the current directory

Example: // UNGEN: delete folder

String Functions

kebabCase: "Hello World" -> hello-world
snakeCase: "Hello World" -> hello_world
camelCase: "Hello World" -> helloWorld
upperCase: "Hello World" -> HELLO WORLD
lowerCase: "Hello World" -> hello world
substitute: subtitute("Hello World", "lo", "ping") -> Helping World
concat: concat("Hello ", "World", "!") -> Hello World!

Languages Supported

Common Line Comment Languages (Go, Rust, C#, Java, PHP, JS/TS, C/C++, YAML, etc)
- // UNGEN: replace "world" with var.appName
- # UNGEN: replace "world" with var.appName
Block Line Comment Languages (CSS)
- /* UNGEN: replace "world" with var.appName */
Note: The Block Line Comment needs to be in a single line
XML Line Comments (XML, HTML)
- 
TSX/JSX
- {/* UNGEN: replace "world" with var.appName */}
Markdown
- [//]: # 'UNGEN: replace "world" with var.appName'

(Create an issue to support other languages)

Language Feature: Injection (for non-commented languages)

In some "languages", line comments are not allowed (like JSON) or not common (like Markdown), UnGen allows you to "inject" Ungen commands into those files before the parser processes the files. All you need to do is create a .ungen file in the same directory, and write your injection commands like so:

// UNGEN: inject file:<filename> on ln <line-number> '<ungen-command'

An example can be found in examples/simple-nodejs/.ungen