Metadata-Version: 2.4
Name: gladlang
Version: 0.1.1
Summary: The GladLang Interpreter
Author: Glad432
License: Copyright (c) 2025 - present GLAD432
        
        Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
        
        The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
        
        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Project-URL: Homepage, https://github.com/gladw-in/gladlang
Keywords: interpreter,language,compiler,educational
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Requires-Python: >=3.10
Description-Content-Type: text/markdown
License-File: LICENSE
Dynamic: license-file

# GladLang

**GladLang is a dynamic, interpreted, object-oriented programming language.** This is a full interpreter built from scratch in Python, complete with a lexer, parser, and runtime environment. It supports modern programming features like closures, classes, inheritance, and robust error handling.

![Lines of code](https://sloc.xyz/github/gladw-in/gladlang)

This is the full overview of the GladLang language, its features, and how to run the interpreter.

## Table of Contents

- [About The Language](#about-the-language)
- [Key Features](#key-features)
- [Getting Started](#getting-started)
    - [Running a Script](#running-a-script)
    - [Using the Interactive Shell](#using-the-interactive-shell)
    - [Building the Executable](#building-the-executable)
- [Language Tour (Syntax Reference)](#language-tour-syntax-reference)
    - [1. Comments](#1-comments)
    - [2. Variables and Data Types](#2-variables-and-data-types)
        - [Variables](#variables)
        - [Numbers](#numbers)
        - [Strings](#strings)
        - [Lists](#lists)
        - [Booleans](#booleans)
        - [Null](#null)
    - [3. Operators](#3-operators)
        - [Arithmetic & Precedence](#arithmetic--precedence)
        - [Comparison & Logical](#comparison--logical)
        - [Increment / Decrement](#increment--decrement)
    - [4. Control Flow](#4-control-flow)
        - [IF Statements](#if-statements)
        - [WHILE Loops](#while-loops)
        - [FOR Loops](#for-loops)
    - [5. Functions](#5-functions)
        - [Named Functions](#named-functions)
        - [Anonymous Functions](#anonymous-functions)
        - [Closures](#closures)
        - [Recursion](#recursion)
    - [6. Object-Oriented Programming (OOP)](#6-object-oriented-programming-oop)
        - [Classes and Instantiation](#classes-and-instantiation)
        - [The `SELF` Keyword](#the-self-keyword)
        - [Inheritance](#inheritance)
        - [Polymorphism](#polymorphism)
    - [7. Built-in Functions](#7-built-in-functions)
- [Error Handling](#error-handling)
- [Running Tests](#running-tests)
- [License](#license)

-----

## About The Language

GladLang is an interpreter for a custom scripting language. It was built as a complete system, demonstrating the core components of a programming language:

  * **Lexer (`lexer.py`):** A tokenizer that scans source code and converts it into a stream of tokens (e.g., `NUMBER`, `STRING`, `IDENTIFIER`, `KEYWORD`, `PLUS`).
  * **Parser (`parser.py`):** A parser that takes the token stream and builds an Abstract Syntax Tree (AST), representing the code's structure.
  * **AST Nodes (`nodes.py`):** A comprehensive set of nodes that define every syntactic structure in the language (e.g., `BinOpNode`, `IfNode`, `FunDefNode`, `ClassNode`).
  * **Runtime (`runtime.py`):** Defines the `Context` and `SymbolTable` for managing variable scope, context (for tracebacks), and closures.
  * **Values (`values.py`):** Defines the language's internal data types (`Number`, `String`, `List`, `Function`, `Class`, `Instance`).
  * **Interpreter (`interpreter.py`):** The core engine that walks the AST and executes the program by visiting each node.
  * **Entry Point (`gladlang.py`):** The main file that ties everything together. It handles command-line arguments, runs files, and starts the interactive shell.

-----

## Key Features

GladLang supports a rich, modern feature set:

  * **Data Types:** Numbers (int/float), Strings, Lists, Booleans, and Null.
  * **Variables:** Dynamic variable assignment with the `LET` keyword.
  * **Operators:** Full set of arithmetic (`+`, `-`, `*`, `/`, `^`), comparison (`==`, `!=`, `<`, `>`), and logical (`AND`, `OR`, `NOT`) operators.
  * **Control Flow:** `IF...THEN...ENDIF`, `WHILE...ENDWHILE`, and `FOR...IN...ENDFOR` loops.
  * **Flow Control:** `BREAK` and `CONTINUE` keywords for loops.
  * **Functions:**
      * First-class citizens (can be passed as arguments and stored in variables).
      * Support for named and anonymous functions.
      * **Closures:** Functions capture their parent's scope.
      * Recursive function calls.
  * **Object-Oriented Programming:**
      * `CLASS...ENDCLASS` syntax.
      * `NEW` keyword for instantiation.
      * `SELF` keyword for instance context.
      * `INHERITS` keyword for class inheritance.
      * Method overriding and polymorphism.
  * **Advanced Operators:** Pre- and post-increment/decrement (`++i`, `i--`).
  * **List Manipulation:** Index access (`my_list[0]`), index assignment (`my_list[0] = 10`), and concatenation (`list1 + list2`).
  * **Built-ins:** `PRINT`, `INPUT`, `STR`, `INT`, `FLOAT`, and `BOOL`.
  * **Error Handling:** Robust, user-friendly runtime error reporting with full tracebacks.

-----

## Getting Started

### Running a Script

You can execute any `.glad` file by passing it as an argument to `gladlang.py`.

```bash
python gladlang.py "test.glad"
```

**Output:**

```
--- OOP & Inheritance Tester ---
--- Creating a Pet ---
A new pet is born!
Sammy makes a generic pet sound.
--- Creating a Dog ---
A new pet is born!
Buddy says: Woof!
Buddy wags its tail.
```

### Using the Interactive Shell

Run the interpreter without any arguments to start the interactive Read-Eval-Print Loop (REPL) shell.

```bash
python gladlang.py
```

**Shell:**

```
Welcome to GladLang (v0.1.0)
Type 'exit' or 'quit' to close the shell.
--------------------------------------------------
GladLang > PRINT "Hello, " + "World!"
Hello, World!
0
GladLang > LET a = 10 * (2 + 3)
0
GladLang > PRINT a
50
0
GladLang > exit
```

## Building the Executable

You can build a **standalone executable** using **PyInstaller**:

```bash
pyinstaller run.py --paths src -F --name gladlang --icon=favicon.ico
```

This will create a single-file executable at `dist/gladlang`.

-----

### Adding to System PATH for Global Use

You can then add it to your system **PATH** so it can be run globally as "**gladlang**" from anywhere.

#### Windows:

1.  **Move or copy** the executable to a folder of your choice, for example:
    ```bash
    move dist\gladlang.exe "C:\Programs\GladLang"
    ```
2.  **Add that folder to your system PATH:**
      * Press **Win + R**, type `sysdm.cpl`, press **Enter**.
      * Go to **Advanced** $\rightarrow$ **Environment Variables**.
      * Under **System variables**, select **Path** $\rightarrow$ **Edit** $\rightarrow$ **New**.
      * Add the full path (e.g., `C:\Programs\GladLang`).
3.  **Open a new terminal and test:**
    ```bash
    gladlang "test_recursion.glad"
    ```

#### macOS / Linux:

1.  **Move** the executable to `/usr/local/bin` (or another directory in your PATH):
    ```bash
    sudo mv dist/gladlang /usr/local/bin/
    ```
2.  **Make sure it's executable:**
    ```bash
    sudo chmod +x /usr/local/bin/gladlang
    ```
3.  **Test it anywhere:**
    ```bash
    gladlang "test_recursion.glad"
    ```

Now you can run GladLang from any folder without prefixing `./dist/`.

-----

## Language Tour (Syntax Reference)

Here is a guide to the GladLang syntax, with examples from the `tests/` directory.

### 1\. Comments

Comments start with `#` and last for the entire line.

```glad
# This is a comment.
LET a = 10 # This is an inline comment
```

### 2\. Variables and Data Types

#### Variables

Variables are assigned using the `LET` keyword.

```glad
LET a = 10
LET b = "Hello"
LET my_list = [a, b, 123]
```

#### Numbers

Numbers can be integers or floats. All standard arithmetic operations are supported.

```glad
LET math_result = (1 + 2) * 3 # 9
LET float_result = 10 / 4     # 2.5
```

#### Strings

Strings are defined with double quotes and support escape characters. They can be concatenated with `+`.

```glad
LET newline = "Hello\nWorld"
LET quoted = "She said, \"This is cool!\""
PRINT "Hello, " + "GladLang"
```

#### Lists

Lists are ordered collections of any type. They support indexing, assignment, and concatenation.

```glad
LET my_list = [1, "hello", 2 * 3, TRUE]

PRINT my_list[1] # Access: "hello"

LET my_list[1] = "world" # Assign
PRINT my_list[1] # "world"

LET other_list = my_list + [FALSE, 100]
```

#### Booleans

Booleans are `TRUE` and `FALSE`. They are the result of comparisons and logical operations.

```glad
LET t = TRUE
LET f = FALSE
PRINT t AND f # 0 (False)
PRINT t OR f  # 1 (True)
PRINT NOT t   # 0 (False)
```

**Truthiness:** `0`, `0.0`, `""`, `NULL`, and `FALSE` are "falsy." All other values (including non-empty strings, non-zero numbers, lists, functions, and classes) are "truthy."

#### Null

The `NULL` keyword represents a null or "nothing" value. It is falsy and prints as `0`. Functions with no `RETURN` statement implicitly return `NULL`.

-----

### 3\. Operators

#### Arithmetic & Precedence

`^` (power), `*`, `/` (division), `+`, `-`. Standard operator precedence is respected.

```glad
PRINT 1 + 2 * 3   # 7
PRINT (1 + 2) * 3 # 9
```

#### Comparison & Logical

  * **Comparison:** `==`, `!=`, `<`, `>`, `<=`, `>=`
  * **Logical:** `AND`, `OR`, `NOT`

<!-- end list -->

```glad
PRINT (10 < 20) AND (10 != 5) # 1 (True)
```

#### Increment / Decrement

Supports C-style pre- and post-increment/decrement operators on variables and list elements.

```glad
LET i = 5
PRINT i++ # 5
PRINT i   # 6
PRINT ++i # 7
PRINT i   # 7

LET my_list = [10, 20]
PRINT my_list[1]++ # 20
PRINT my_list[1]   # 21
```

-----

### 4\. Control Flow

#### IF Statements

Uses `IF...THEN...ENDIF` syntax.

```glad
LET num = -5
IF num < 0 THEN
  PRINT "It is negative."
ENDIF
```

#### WHILE Loops

Loops while a condition is `TRUE`.

```glad
LET i = 3
WHILE i > 0
  PRINT "i = " + i
  LET i = i - 1
ENDWHILE

# Prints:
# i = 3
# i = 2
# i = 1
```

#### FOR Loops

Iterates over the elements of a list.

```glad
LET my_list = ["apple", "banana", "cherry"]
FOR item IN my_list
  PRINT "Item: " + item
ENDFOR
```

**`BREAK` and `CONTINUE`** are supported in both `WHILE` and `FOR` loops.

-----

### 5\. Functions

#### Named Functions

Defined with `DEF...ENDEF`. Arguments are passed by value. `RETURN` sends a value back.

```glad
DEF add(a, b)
  RETURN a + b
ENDEF

LET sum = add(10, 5)
PRINT sum # 15
```

#### Anonymous Functions

Functions can be defined without a name, perfect for assigning to variables.

```glad
LET double = DEF(x)
  RETURN x * 2
ENDEF

PRINT double(5) # 10
```

#### Closures

Functions capture variables from their parent scope.

```glad
DEF create_greeter(greeting)
  DEF greeter_func(name)
    # 'greeting' is "closed over" from the parent
    RETURN greeting + ", " + name + "!"
  ENDEF
  RETURN greeter_func
ENDEF

LET say_hello = create_greeter("Hello")
PRINT say_hello("Alex") # "Hello, Alex!"
```

#### Recursion

Functions can call themselves.

```glad
DEF fib(n)
  IF n <= 1 THEN
    RETURN n
  ENDIF
  RETURN fib(n - 1) + fib(n - 2)
ENDEF

PRINT fib(7) # 13
```

-----

### 6\. Object-Oriented Programming (OOP)

#### Classes and Instantiation

Use `CLASS...ENDCLASS` to define classes and `NEW` to create instances. The constructor is `init`.

```glad
CLASS Counter
  DEF init(self)
    SELF.count = 0 # 'SELF' is the instance
  ENDEF
  
  DEF increment(self)
    SELF.count = SELF.count + 1
  ENDEF
  
  DEF get_count(self)
    RETURN SELF.count
  ENDEF
ENDCLASS
```

#### The `SELF` Keyword

`SELF` is the mandatory first argument for all methods and is used to access instance attributes and methods.

```glad
LET c = NEW Counter()
c.increment()
PRINT c.get_count() # 1
```

#### Inheritance

Use the `INHERITS` keyword. Methods can be overridden by the child class.

```glad
CLASS Pet
  DEF init(self, name)
    SELF.name = name
  ENDEF
  
  DEF speak(self)
    PRINT SELF.name + " makes a generic pet sound."
  ENDEF
ENDCLASS

CLASS Dog INHERITS Pet
  # Override the 'speak' method
  DEF speak(self)
    PRINT SELF.name + " says: Woof!"
  ENDEF
ENDCLASS

LET my_dog = NEW Dog("Buddy")
my_dog.speak() # "Buddy says: Woof!"
```

#### Polymorphism

When a base class method calls another method on `SELF`, it will correctly use the **child's overridden version**.

```glad
CLASS Pet
  DEF introduce(self)
    PRINT "I am a pet and I say:"
    SELF.speak() # This will call the child's 'speak'
  ENDEF
  
  DEF speak(self)
    PRINT "(Generic pet sound)"
  ENDEF
ENDCLASS

CLASS Cat INHERITS Pet
  DEF speak(self)
    PRINT "Meow!"
  ENDEF
ENDCLASS

LET my_cat = NEW Cat("Whiskers")
my_cat.introduce()
# Prints:
# I am a pet and I say:
# Meow!
```

-----

### 7\. Built-in Functions

  * `PRINT(value)`: Prints a value to the console.
  * `INPUT()`: Reads a line of text from the user as a String.
  * `STR(value)`: Casts a value to a String.
  * `INT(value)`: Casts a String or Float to an Integer.
  * `FLOAT(value)`: Casts a String or Integer to a Float.
  * `BOOL(value)`: Casts a value to its Boolean representation (`TRUE` or `FALSE`).

-----

## Error Handling

GladLang features detailed error handling and prints full tracebacks for runtime errors, making debugging easy.

**Example: Name Error** (`test_name_error.glad`)

```
Traceback (most recent call last):
  File test_name_error.glad, line 6, in <program>
Runtime Error: 'b' is not defined
```

**Example: Type Error** (`test_type_error.glad` with input "5")

```
Traceback (most recent call last):
  File test_type_error.glad, line 6, in <program>
Runtime Error: Illegal operation
```

**Example: Argument Error** (`test_arg_error.glad`)

```
Traceback (most recent call last):
  File test_arg_error.glad, line 7, in <program>
  File test_arg_error.glad, line 4, in add
Runtime Error: Incorrect argument count for 'add'. Expected 2, got 3
```

-----

## Running Tests

The `tests/` directory contains a comprehensive suite of `.glad` files to test every feature of the language. You can run any test by executing it with the interpreter:

```bash
python gladlang.py "test_closures.glad"
python gladlang.py "test_lists.glad"
python gladlang.py "test_polymorphism.glad"

```

or 

```bash
gladlang "test_closures.glad"
gladlang "test_lists.glad"
gladlang "test_polymorphism.glad"
```

## License

You can use this under the MIT License. See [LICENSE](LICENSE) for more details.
