> ## Documentation Index
> Fetch the complete documentation index at: https://docs.iriscode.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Refactor language coverage

> Language support depends on the evidence each detector can prove. The generated table separates implemented suggestions from inapplicable syntax and omissions found during real-source review.

Language support depends on the evidence each detector can prove. The generated table separates implemented suggestions from inapplicable syntax and omissions found during real-source review.

## Coverage

`built` means implemented, not behaviour-preserving. Component rows for TypeScript and JavaScript require JSX/TSX; they are inapplicable to ordinary non-component files. Vue and Svelte use their native component structure. A built suggestion can still refuse an ambiguous range.

| Suggestion | TypeScript | JavaScript | Go | Python | Ruby | C# | Java | Rust | Vue | Svelte |
| - | - | - | - | - | - | - | - | - | - | - |
| `extract-constants` | left-out | left-out | built | left-out | built | left-out | left-out | built | built | left-out |
| `move-function-cluster` | built | built | left-out | built | built | left-out | built | built | built | built |
| `move-types` | built | not-applicable | built | built | not-applicable | built | built | built | built | left-out |
| `split-declarations` | built | built | built | built | built | built | built | left-out | built | built |
| `delete-unused-function` | built | built | left-out | left-out | built | built | built | built | built | built |
| `extract-function` | left-out | left-out | left-out | left-out | left-out | left-out | left-out | left-out | left-out | built |
| `early-return` | built | built | built | left-out | built | built | built | built | left-out | built |
| `lookup-table` | built | left-out | left-out | left-out | left-out | left-out | built | left-out | left-out | built |
| `options-object` | built | built | built | built | built | built | built | built | built | built |
| `move-imports-with-code` | built | built | left-out | built | left-out | left-out | built | built | built | built |
| `extract-duplicate` | left-out | left-out | left-out | built | built | left-out | built | left-out | built | left-out |
| `name-magic-numbers` | left-out | left-out | left-out | left-out | left-out | left-out | built | left-out | left-out | left-out |
| `consolidate-state` | left-out | built | not-applicable | not-applicable | not-applicable | not-applicable | not-applicable | not-applicable | built | left-out |
| `derive-without-effect` | built | built | not-applicable | not-applicable | not-applicable | not-applicable | not-applicable | not-applicable | built | built |
| `extract-component` | built | built | not-applicable | not-applicable | not-applicable | not-applicable | not-applicable | not-applicable | built | left-out |

## Omissions and review

Every `left-out` cell above has a measured reason, which each plan reports in its coverage for that language. The table below explains the omissions that are most often asked about.

| Suggestion | Language | Reason |
| - | - | - |
| `lookup-table` | Ruby and Rust | Class/pattern arms, payload bindings and guards are not scalar lookup entries |
| `move-imports-with-code` | Ruby | Require statements do not identify imported bindings, so exclusive use cannot be proved |
| `name-magic-numbers` | Ruby and Svelte | Opcode data and chart observations already carry domain meaning |
| `extract-function` | Java | Small early-exit guards in large files exceeded the review threshold |
| `move-types` | JavaScript and Ruby | No separate type-declaration syntax; classes use split-declarations |
| State/effect/component suggestions | Non-component source | These suggestions need React JSX, Vue or Svelte component code |

The review threshold removes a suggestion from a language when more than one in ten observed suggestions is definite nonsense. The [generated review evidence](/trust/accuracy-benchmark#refactor-suggestion-evidence) records observations and omissions from a review of 200 plans across the ten languages. No overall suggestion accuracy is claimed.

## Related pages

[Overview](/refactor/overview), [fixes and suggestions](/refactor/reference), [conventions](/refactor/conventions), [verification](/refactor/verification), [configuration](/refactor/configuration), [agent integration](/refactor/agents), and [language coverage](/refactor/language-coverage).


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