lux/website/lux-site/LUX_WEAKNESSES.md

Lux Weaknesses Discovered During Website Development

This document tracks issues and limitations discovered while building the Lux website in Lux.

Fixed Issues

1. Module Import System Not Working (FIXED)

Description: The import statement wasn't working for importing standard library modules.

Root Cause: Two issues were found:

1. Parser didn't skip newlines inside list expressions, causing parse errors in multi-line lists
2. Functions in stdlib modules weren't marked as pub (public), so they weren't exported

Fix:

1. Added skip_newlines() calls to parse_list_expr() in parser.rs
2. Added pub keyword to all exported functions in stdlib/html.lux

Status: FIXED

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2. Parse Error in html.lux (FIXED)

Description: When trying to load files that import the html module, there was a parse error at line 196-197.

Error Message:

Module error: Module error in '<main>': Parse error: Parse error at 196-197: Unexpected token: \n

Root Cause: The parser's parse_list_expr() function didn't handle newlines between list elements.

Fix: Added skip_newlines() calls after [, after each element, and after commas in list expressions.

Status: FIXED

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3. List.foldl Renamed to List.fold (FIXED)

Description: The html.lux file used List.foldl but the built-in List module exports List.fold.

Fix: Changed List.foldl to List.fold in stdlib/html.lux.

Status: FIXED

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Minor Issues

4. String.replace Verified Working

Description: The escapeHtml function in html.lux uses String.replace.

Status: VERIFIED WORKING - String.replace is implemented in the interpreter.

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5. FileSystem Effect Not Fully Implemented

Description: For static site generation, we need FileSystem.mkdir, FileSystem.write, FileSystem.copy operations. These may not be fully implemented.

Workaround: Use Bash commands via scripts.

Status: Needs verification

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6. List.concat Verified Working

Description: The List.concat function is used in html.lux document generation.

Status: VERIFIED WORKING - List.concat is implemented in the interpreter.

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Feature Gaps

7. No Built-in Static Site Generation

Description: There's no built-in way to generate static HTML files from Lux. A static site generator effect or module would be helpful.

Recommendation: Add a FileSystem effect with:

• mkdir(path: String): Unit
• write(path: String, content: String): Unit
• copy(src: String, dst: String): Unit
• readDir(path: String): List<String>

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8. No Template String Support

Description: Multi-line strings and template literals (like JavaScript's backticks) would make HTML generation much easier.

Current Approach:

let html = "<div class=\"" + className + "\">" + content + "</div>"

Better Approach (not available):

let html = `<div class="${className}">${content}</div>`

Status: Feature request

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9. No Markdown Parser

Description: A built-in Markdown parser would be valuable for documentation sites.

Status: Feature request

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Working Features

These features work correctly and can be used for website generation:

1. String concatenation - Works with + operator
2. Conditional expressions - if/then/else works
3. Console output - Console.print() works
4. Basic types - String, Int, Bool work
5. Let bindings - Variable assignment works
6. Functions - Function definitions work
7. Module imports - Works with import stdlib/module
8. Html module - Fully functional for generating HTML strings

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Recommendations

For Website MVP

The module system now works! The website can be:

1. Generated from Lux using the html module for HTML rendering
2. CSS separate file (already done in static/style.css)
3. Lux code examples embedded as text in HTML

For Future

1. Add FileSystem effect for writing generated HTML to files
2. Markdown-based documentation parsed and rendered by Lux
3. Live playground using WASM compilation

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Test Results

Feature	Status	Notes
String concatenation	Works	"<" + tag + ">"
Conditionals	Works	if x then y else z
Console.print	Works	Basic output
Module imports	Works	import stdlib/html
Html module	Works	Full HTML generation
List.fold	Works	Fold over lists
List.concat	Works	Concatenate list of lists
String.replace	Works	String replacement
FileSystem	Unknown	Not tested

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Date Log

Date	Finding
2026-02-16	Module import system not working, parse error at line 196-197 in html.lux
2026-02-16	Fixed: Parser newline handling in list expressions
2026-02-16	Fixed: Added pub to stdlib/html.lux exports
2026-02-16	Fixed: Changed List.foldl to List.fold