Learn the basics of AutoCAD and More!

Lesson 5.14 – Organizing LISP Files

πŸ—ƒοΈ Lesson 5.14 – Organizing LISP Files

Learn how to structure your AutoLISP code for clarity, reusability, and long-term maintenance.


πŸ“š What You’ll Learn

By the end of this lesson, you’ll be able to:

  • Structure your AutoLISP code using best practices
  • Separate reusable logic from UI and drawing-specific parts
  • Use consistent formatting, indentation, and naming conventions
  • Write clear comments and in-line documentation

🧠 Why It Matters

Well-organized LISP code is easier to debug, extend, and reuse. Whether you’re sharing routines with coworkers or building your own toolkit, clarity and modularity make your work scalable and professional.


πŸ› οΈ Tools You’ll Use

Tool / ConceptPurpose
defunDefines functions
princ, promptClean output and user messaging
;;;, ;;, ;Comment levels for sectioning and explanation
Modular file structureKeeps separate files for UI, utilities, and loaders

🧭 Lesson Structure

1️⃣ Structure Your Files Logically

A well-structured file might look like this:

;;; greet.lsp
;;; Greeting utility for startup welcome

(defun c:greet ( / )
(alert "Welcome to the drafting environment.")
(princ)
)

πŸ“Œ File name matches its main function

πŸ“Œ Header comment describes purpose

πŸ“Œ princ keeps the command line clean

2️⃣ Use Consistent Commenting

SymbolUse CaseExample
;;;Section heading;;; --- Initialization Functions ---
;;Block/function summary;; Greets user with alert box
;Inline or line explanation; Set variable to default

3️⃣ Separate Utilities and Loaders

πŸ“ Suggested folder and file structure:

/LISP/
β”œβ”€β”€ utilities/
β”‚ β”œβ”€β”€ math_utils.lsp
β”‚ β”œβ”€β”€ string_utils.lsp
β”œβ”€β”€ drawing/
β”‚ β”œβ”€β”€ layer_setup.lsp
β”‚ β”œβ”€β”€ titleblock_fill.lsp
β”œβ”€β”€ startup/
β”‚ └── startup.lsp
└── main_loader.lsp

n main_loader.lsp:

(load "utilities/math_utils.lsp")
(load "drawing/layer_setup.lsp")
(load "startup/startup.lsp")

4️⃣ Use Meaningful Function Names

Bad NameBetter NameWhy
c:doitc:createlayersMore descriptive
fget-drawing-unitsSelf-documenting
xxlayerListConveys purpose

βœ… Lesson Checklist

TaskCompleted
Created LISP file with clear function definition☐
Used consistent and appropriate commenting☐
Organized files into folders based on purpose☐
Wrote modular functions with self-explanatory names☐

πŸ“Œ Quick Tips

TipWhy It Helps
Keep one major routine per fileMakes debugging and loading easier
Always add (princ) at the endPrevents function echoing at command line
Use consistent indentation (2-4 spaces)Improves readability and collaboration
Group helper functions under commentsImproves section navigation

🧩 Real-World Applications

ScenarioHow Structure Helps
Large project with 20+ toolsOrganize by function (layer, block, utility)
Team working on shared routinesClear comments and names prevent confusion
Debugging old codeStructure and documentation reduce errors

πŸ“ Files and Resources

File / ResourceDescription
sample_structured.lspA properly structured, commented sample LISP file
function_naming_cheatsheet.docxTips and examples for naming conventions
lisp_folder_structure_template.docxSuggested layout for your LISP project folder

πŸ“– Review Table

ElementBest PracticeExample
defunDescriptive, with proper parameters(defun c:createlayers ( / ))
CommentsUse ;;; headers, ; inline notes;;; --- Start of Routine ---
File namingMatches purposetitleblock_fill.lsp
Folder namingFollows type or domain/utilities/, /drawing/, /startup/