Logo Interpreter & Debugger for VSCode

Standalone VSCode extension with interpreter and debugger for the Logo programming language.

Features

• Logo Language Support: Implements the Logo interpreter directly in the extension
• Code Suggestions: Auto-completion for Logo commands and procedures
• Live Preview: Preview panel renders Logo graphics in real-time as you save your code.
• Save images: Right-click on the preview panel & select "Save as PNG".
• Debugging: Set breakpoints, step through code, inspect variables
• Syntax Highlighting: Logo language syntax highlighting
• Syntax Checking: Basic syntax error detection
• Variable Inspection: View turtle state (position, angle, pen status) and program variables

Supported Logo Commands

Turtle Movement

• FD / FORWARD - Move forward
• BK / BACK / BACKWARD - Move backward
• RT / RIGHT - Turn right
• LT / LEFT - Turn left
• PU / PENUP - Lift pen
• PD / PENDOWN - Put pen down

Drawing

• CS / CLEARSCREEN - Clear screen and reset turtle
• CLEAR - Clear the drawing without resetting turtle position
• SETPENCOLOR / SETPC - Set pen color
• HIDETURTLE / HT - Hide turtle cursor
• SHOWTURTLE / ST - Show turtle cursor
• PU / PENUP - Lift pen
• PD / PENDOWN - Put pen down

Control Structures

• REPEAT n [commands] - Repeat commands n times
• IF condition [commands] - Conditional execution
• IFELSE condition [true-commands] [false-commands] - Conditional execution with two branches
• LOAD "path.logo / LOAD :filename - Load and execute another Logo file
  • Loaded files are executed immediately
  • Procedures defined in loaded files become available to the current program
  • Relative paths are resolved from the file containing the LOAD command
  • Repeated LOAD commands re-execute the target file
• TO name :param1 :param2 ... END - Define procedures

Variables and Expressions

• :variable - Variable reference
• :var = expression / MAKE "var expression - Variable assignment
• RANDOM n - Random integer in [0, n), or 0 when n <= 0
• INT expression - Integer part of a number, truncated toward zero
• REMAINDER a b - Remainder using truncation toward zero, matching a - INT(a / b) * b
• Arithmetic operators: +, -, *, /
• Comparison operators: =, <, >
• Example: MAKE "A (RANDOM 10), PRINT INT (132 / 10), or PRINT REMAINDER 132 10

Additional Commands

• ARC - Move along an arc
• PRINT / PR - Print a value to the output

Usage

Preview

1. Open a .logo file in VSCode
2. Press Ctrl+Shift+V or click the preview icon in the editor title bar
3. The preview panel will open, displaying the Logo graphics.
4. The preview automatically updates whenever you save the file.

Debugging

1. Open a .logo file in VSCode
2. Press F5 or select "Debug Logo Program" from the debug menu
3. The graphics window will open automatically
4. Use standard debugging controls:
   • F10: Step over
   • F11: Step into
   • Shift+F11: Step out
   • F5: Continue
   • Shift+F5: Stop

Examples

You can find example programs here