fix(interpreter): brace expansion before other expansions

[chaliy]

Requested by Михайло · project thread

What changed

Brace expansion now runs first, on the parsed word, as in bash. Only unquoted literal text takes part; variables, substitutions and quoted segments are opaque. The lexer no longer has ad hoc readers for words starting with { (they ignored quotes and split words).

Why

Pseudo-linus oracle items shell/expansion-order and shell/brace-expansion. Brace-expanding data from a variable is also an injection-shaped bug (data turning into multiple words).

Before / After

Script	Before	After (= bash 5.2)
y='{a,b}'; echo $y	a b	{a,b}
n=3; echo {1..$n}	1 2 3	{1..3}
echo {01..10..3}	1 4 7 10	01 04 07 10
echo "{a,b}"x{1,2}	{a,b}x 1 2	{a,b}x1 {a,b}x2
echo '{a,b}'{c,d}	{a,b} c d	{a,b}c {a,b}d
echo {a,"b c"}	a "b c"	a b c
echo {x}{a,b}	{x} a b	{x}a {x}b
echo {,a}	a	a
echo a{b\,c,d}	ab\ ac ad	ab,c ad

New spec brace-expansion-order.test.sh (7 cases, verified against bash); brace_empty_item lost its bash_diff.

Risk

Medium: lexer change for words containing {. All lib, integration (spec) and bash_comparison tests pass. Known gap, recorded in limitations: bash expands raw text, so $v{1,2} reads $v1; we keep $v and append.

Checklist

• Tests (spec, verified against bash)
• cargo fmt, cargo clippy -D warnings
• lib + integration + bash_comparison tests
• knowledge updated (parser.md, limitations.md, log.md)

https://claude.ai/code/session_019aFikmptPc91Fj4N2iDXQA

---

Generated by Claude Code

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Workers

The latest updates on your project. Learn more about integrating Git with Workers.

Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	bashkit	3ff18b0	Commit Preview URL Branch Preview URL	Oct 07 2026, 05:23 PM