Function estimateExtractCost

ext/regex.go:338–357

()

}

func estimateExtractCost() checker.FunctionEstimator {
	return func(c checker.CostEstimator, target *checker.AstNode, args []checker.AstNode) *checker.CallEstimate {
		if len(args) == 2 {
			targetSize := estimateSize(c, args[0])
			// Fixed size estimate of +1 is added for safety from zero size args.
			// The target cost is the size of the target string, scaled by a traversal factor.
			targetCost := targetSize.Add(fixedSizeEstimate(1)).MultiplyByCostFactor(common.StringTraversalCostFactor)
			// The regex cost is the size of the regex pattern, scaled by a complexity factor.
			regexCost := estimateSize(c, args[1]).Add(fixedSizeEstimate(1)).MultiplyByCostFactor(common.RegexStringLengthCostFactor)
			// The result is a single string. Worst Case: it's the size of the entire target.
			resultSize := rangedSizeEstimate(0, targetSize.Max)
			// The total cost is the search cost (target + regex) plus the allocation cost for the result string.
			return callEstimate(
				regexCost.Multiply(targetCost).Add(checker.CostEstimate(resultSize)),
				&resultSize,
			)
		}
		return nil
	}
}

func estimateExtractAllCost() checker.FunctionEstimator {
	return func(c checker.CostEstimator, target *checker.AstNode, args []checker.AstNode) *checker.CallEstimate {