📝 docs: Drop the reassignment section the language never had

[135yshr]

Overview

The language spec had a "Reassignment" section with AssignStmt = identifier "=" Expr newline ., but Meow has no reassignment. A program that writes x = 5 after nyan x = 1 is refused with "Variable x already declared in this scope". The reference already says bindings are immutable.

This PR removes that section from docs/spec.md and from its website copy, website/content/doc/spec.md.

x = 42 for a name that isn't bound yet is still valid: the parser reads it as an implicit declaration. That form moves into the Variable Declaration grammar as a second VarStmt alternative:

VarStmt = "nyan" identifier [ TypeExpr ] "=" Expr newline
        | identifier "=" Expr newline .

It takes no type annotation, because x int = 1 doesn't parse. The section also says that writing x = ... for a name already bound in the same or an enclosing scope is a compile error, not a reassignment. The two spec files are still identical apart from their front matter.

Verification

• go test ./docs/ passes, including TestTheWebsiteSaysWhatTheDocumentsSay, which checks that the spec and the website copy match.
• go test ./... passes.
• I ran meow run on three programs:
  • x = 42 followed by nya(x) prints 42.
  • x = 1 followed by x = 2 is refused.
  • x int = 1 fails to parse.
• Nothing links to #reassignment, and AssignStmt appears nowhere else in the docs.

Impact

Documentation only. No code changes.

AI Session

https://claude.ai/code/session_01Scc7p1RecmFoikhcXwnTMu

Checklist

• The docs and the website copy are updated together
• Tests pass

🤖 Generated with Claude Code

https://claude.ai/code/session_01Scc7p1RecmFoikhcXwnTMu

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-28T06:59:54.047958Z	bdec039	PR opened

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Advanced

Run ID: 5aa392e3-306f-4a09-9472-3ca6f1a1b469

📥 Commits

Reviewing files that changed from the base of the PR and between bdec039 and f26e793.

📒 Files selected for processing (2)

• docs/spec.md
• website/content/doc/spec.md

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📝 Walkthrough

Walkthrough

Both specification documents now allow declarations without nyan when the name has no type annotation. They state that assigning to a name already bound in the same or an enclosing scope is a compile error, and remove the reassignment section.

Changes

Specification updates

Layer / File(s)	Summary
Document declaration syntax docs/spec.md, website/content/doc/spec.md	Both documents add the identifier = Expr declaration form, explain its use for untyped names, and include an example.
Document binding rules docs/spec.md, website/content/doc/spec.md	Both documents state that assigning to a name already bound in the same or an enclosing scope is a compile error. They remove the reassignment grammar and description.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to f26e7

The documentation updates match the existing declaration and binding behavior; no merge-blocking issue is evident.

Architecture Summary

Architecture risk: 🔵 Low · up to f26e7

The change affects 2 systems.

Changed systems: docs, website

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — docs (service) was modified; 1 changed file maps to changed impact.
• observed — website (service) was modified; 1 changed file maps to changed impact.

Before / after behavior

• observed — Modified behavior in docs/spec.md: The variable declaration grammar now permits identifier = Expr without nyan, while retaining the existing nyan form.
• observed — Modified behavior in docs/spec.md: The declaration description now says nyan may be omitted for untyped names and that the omitted-keyword form declares a variable.
• observed — Modified behavior in docs/spec.md: The examples now include a declaration written without nyan.
• observed — Modified behavior in docs/spec.md: The specification now states that bindings cannot be rebound and that assigning to a name bound in the same or an enclosing scope is a compile error.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the primary change: removing the reassignment section from the language documentation.
Description check	✅ Passed	The description includes the required Overview, Verification, Impact, AI Session, and Checklist sections. It explains the documentation changes, verification steps, affected areas, and test results. S…

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_{A rabbit reads the syntax with care,
“No nyan is needed here.”
Bound names stay where they have been,
No reassignment slips between.
The specs now tell the rules quite clear.}

_{Comment @coderabbitai help to get the list of available commands.}

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