fix(grammar): use fixed-length look-behind in FunC function definitions - #344
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i582 merged 1 commit intoJun 22, 2026
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The function-definition rule used a variable-length look-behind,
`(?<=^|[;{]\s*)`. Oniguruma accepts it, so VS Code highlighting is
unaffected, but engines that require fixed-length look-behind reject it
(for example the grammar compiler GitHub Linguist uses), which prevents
the grammar from being reused there.
Split the assertion into two fixed-length look-behinds, `(?<=^)` and
`(?<=[;{])`, and move `\s*` into the match. Behavior is unchanged: a
function name is still matched at the start of a line, or after `;` or `{`
with optional whitespace.
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Hey! Sounds great, thank you! |
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Thanks! Glad it helps. |
i582
approved these changes
Jun 22, 2026
0xnirapod
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Jun 22, 2026
Switch the vendored grammar from the archived tolk-vscode to TON's maintained ton-language-server, which tracks current Tolk syntax. It became usable in Linguist once the FunC grammar's variable-length look-behind was made fixed-length upstream (ton-blockchain/ton-language-server#344).
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What
The FunC TextMate grammar's function-definition rule uses a variable-length look-behind:
Why
Oniguruma (used by VS Code) accepts this, so editor highlighting is unaffected. But regex engines that require fixed-length look-behind reject it. GitHub Linguist's grammar compiler, for instance, fails with:
That blocks
func.tmLanguage.json(and with it the rest of the ton-language-server grammars, which compile as a set) from being reused for syntax highlighting on GitHub.Fix
Split the assertion into two fixed-length look-behinds and move
\s*into the match:Behavior is unchanged: a function name is matched at the start of a line, or after
;or{with optional whitespace. Verified locally by compiling the grammars with Linguist's grammar compiler. All five now compile cleanly.