function matchInjections()

in src/grammar.ts [804:857]
42 lines of code
8 McCabe index (conditional complexity)

function matchInjections(injections: Injection[], grammar: Grammar, lineText: OnigString, isFirstLine: boolean, linePos: number, stack: StackElement, anchorPosition: number): IMatchInjectionsResult | null {
	// The lower the better
	let bestMatchRating = Number.MAX_VALUE;
	let bestMatchCaptureIndices: IOnigCaptureIndex[] | null = null;
	let bestMatchRuleId: number;
	let bestMatchResultPriority: number = 0;

	const scopes = stack.contentNameScopesList.generateScopes();

	for (let i = 0, len = injections.length; i < len; i++) {
		const injection = injections[i];
		if (!injection.matcher(scopes)) {
			// injection selector doesn't match stack
			continue;
		}
		const rule = grammar.getRule(injection.ruleId);
		const { ruleScanner, findOptions } = prepareRuleSearch(rule, grammar, null, isFirstLine, linePos === anchorPosition);
		const matchResult = ruleScanner.scanner.findNextMatchSync(lineText, linePos, findOptions);
		if (!matchResult) {
			continue;
		}

		if (DebugFlags.InDebugMode) {
			console.log(`  matched injection: ${injection.debugSelector}`);
			console.log(debugCompiledRuleToString(ruleScanner));
		}

		const matchRating = matchResult.captureIndices[0].start;
		if (matchRating >= bestMatchRating) {
			// Injections are sorted by priority, so the previous injection had a better or equal priority
			continue;
		}

		bestMatchRating = matchRating;
		bestMatchCaptureIndices = matchResult.captureIndices;
		bestMatchRuleId = ruleScanner.rules[matchResult.index];
		bestMatchResultPriority = injection.priority;

		if (bestMatchRating === linePos) {
			// No more need to look at the rest of the injections.
			break;
		}
	}

	if (bestMatchCaptureIndices) {
		return {
			priorityMatch: bestMatchResultPriority === -1,
			captureIndices: bestMatchCaptureIndices,
			matchedRuleId: bestMatchRuleId!
		};
	}

	return null;
}