PLAIN — Plain Language Programming

A programming language that reads like plain English.

No brackets. No semicolons. No cryptic symbols. Just sentences.

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✨ Try it Online

→ Open the PLAIN Playground (open playground/index.html in your browser)

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📦 Install the CLI

npm install -g plain-lang

🚀 Quick Start

Create a file called hello.plain:

set name to "World"
say "Hello, " + name + "!"

Run it:

plain hello.plain

Or start the interactive REPL:

plain

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📖 Language Reference

Variables

set name to "Parth"
set age to 19
set price to 299.99

Output & Input

say "Hello, world!"
say "Value: " + myVar
ask "What is your name?" and store in username
say "Hi, " + username

Math

set result to 10 + 5 * 2
set area to width * height
set power to 2 ^ 10         -- 1024
set remainder to 17 % 5     -- 2
calculate 3.14 * r ^ 2 and store in circle_area

Conditions

if score >= 90 then
  say "Grade A"
otherwise if score >= 75 then
  say "Grade B"
otherwise
  say "Try again"
end

Operators: = != > < >= <= and or not

Loops

-- Repeat N times
repeat 5 times
  say "Hello!"
end

-- Counted loop
count from 1 to 10 as i
  say i
end

-- Loop over a list
for each item in myList
  say item
end

Lists

create list fruits
add "apple" to fruits
add "mango" to fruits
say count of fruits          -- 2
say item 1 in fruits         -- apple

Functions

define step greet with name
  say "Hello, " + name + "!"
end step

define step add with a, b
  give back a + b
end step

run step greet with "Parth"
set total to run step add with 10, 20
say total

Data Tables

create table students
set headers of students to "Name", "Score", "Grade"
add row "Parth", 95, "A" to students
add row "Vedant", 82, "B" to students
show table students

Web Requests

fetch "https://api.example.com/data" and store in response
say response

Other

wait 2          -- pause 2 seconds
stop            -- exit program
-- comment      -- this is a comment

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🗂️ Project Structure

plain-lang/
├── playground/          # Browser-based IDE & landing page
│   ├── index.html       # Landing page + playground app
│   ├── style.css        # All styles
│   ├── interpreter.js   # Browser build of interpreter
│   └── app.js           # Playground UI logic
├── src/
│   ├── interpreter.js   # Core language runtime
│   └── cli.js           # CLI entry point (plain command)
├── examples/
│   ├── hello.plain
│   ├── calculator.plain
│   └── grades.plain
├── package.json
└── README.md

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🌐 Publishing

npm

npm login
npm publish

GitHub Pages (playground)

Push the playground/ folder to a gh-pages branch:

git subtree push --prefix playground origin gh-pages

Vercel / Netlify

Set the root directory to playground/ and deploy.

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💡 Roadmap

• Syntax highlighting VS Code extension
• File I/O (read file, write file)
• String manipulation (length of, upper, lower)
• Type checking (is number, is text)
• Multi-file imports
• WASM build for faster browser execution

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🧑‍💻 Author

Made with ❤️ by Parth Pradip Bhosale

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📄 License

MIT — free to use, share, and modify.