fix: tasks 1-6 bug fixes, fmt crate, and stdlib return type shapes

[walonCode]

Summary

• Parser — replace {:?} debug output with human-readable token names in all error messages; add default arm to switch statement parsing
• Evaluator — overflow protection on ++/-- using checked_add/checked_sub; hard error on negative array index; error on assigning to undeclared variable
• Stdlib — restore time.sleep guard that was commented out; add fmt.format type validation for %d/%f/%s placeholders; fix edge cases across array, hash, http, json, rand, strings
• fmt crate — add formatter skeleton (formatter.rs), extend lint rules and commands
• INTERNALS.md — language pipeline documentation
• Docs — stdlib returns column now shows specific shapes: [string], [[any, any]], { status: integer, ok: bool, body: string } instead of plain hash/array

Commits

1. fix(parser) — debug output + switch default arm
2. fix(evaluator) — overflow, negative index, undeclared assign
3. fix(stdlib) — time.sleep, fmt.format, module edge cases
4. feat(fmt) — formatter foundation + lint rules
5. docs(stdlib) — specific return type shapes

Test plan

• cargo build --release passes
• REPL error messages no longer show {:?} debug format
• switch with default arm works
• let x = 9223372036854775807; x++; returns overflow error, not silent wrap
• let a = [1,2,3]; a[-1] = 0; returns index error
• time.sleep(100) works without panic
• Stdlib page shows 3 columns with shaped returns

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
code-lang	Ready	Preview, Comment	Jun 26, 2026 7:22am