DRAW: A DSL for Fractals and Pattern-Based Graphics

Description

The goal of the implemented DSL (Domain-Specific Language) is to provide a language that allows for the design and drawing of flat figures, particularly figures that follow specific patterns, such as fractals, with a special focus on trees. This project is developed as part of the Compilation course and is designed to facilitate the creation of graphics through a set of rules and axioms.

Authors

• Dianelys Cruz Mengana (C-311)
• Jordan Pla González (C-311)
• Leandro Hernández Nuñez (C-312)

Language Features

To define figures, it is necessary to specify their identifier <name> and the color that will be used to draw them (if not defined, they are drawn in black). The definition of a figure is divided into two sections:

• Set of Rules (optional): Instructions that allow for recursion and the creation of figures.
• Axiom: The execution body of the figure from which rules can be accessed.

Language Instructions

• left <expression>: Changes the cursor's direction to the left.
• right <expression>: Changes the cursor's direction to the right.
• line <expression>: Draws a line with the resulting length.
• jump <expression1>,<expression2>: Changes the cursor's coordinates to (expression1, expression2).
• push: Saves the current coordinates onto a stack.
• pop: Returns the cursor to the coordinates at the top of the stack.
• call_shape <shape_name>: Draws the specified shape in shape_name.
• call_rule <rule_name> (expression): Executes the specified rule.
• <variable> = <expression>: Assigns the result to a variable.
• <variable> = get_x: Assigns the current x-coordinate to a variable.
• <variable> = get_y: Assigns the current y-coordinate to a variable.
• set_x <expression>: Changes the current x-coordinate.
• set_y <expression>: Changes the current y-coordinate.

The grammar used is unambiguous, allowing for a unique left derivation for each valid string. An LALR algorithm has been used to resolve it.

Compiler Architecture

• Lexer: The lexer is implemented using the ply library for ease of use.
• Parser: Similarly, it uses ply, leveraging its efficiency with LALR parsers.
• AST: An abstract syntax tree is constructed using a hierarchy of classes found in utils.py.
• Semantic Analysis: The semantic analysis utilizes the visitor pattern to validate contexts and collect types, located in the semantics.visitors directory.
• Interpreter: The interpreter relies on Python's class hierarchy that defines the AST.

Installation

To install the required packages, run:

pip install -r requirements.txt

Running the Project

To execute the project, use:

python main.py

Conclusion

This project provides a DSL for creating complex graphic figures through a rule-based system. It allows users to explore concepts such as fractals and trees through graphic programming.