mirror of
https://github.com/anchore/syft
synced 2024-11-10 06:14:16 +00:00
40 lines
1.6 KiB
Go
40 lines
1.6 KiB
Go
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package internal
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import "regexp"
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// MatchNamedCaptureGroups takes a regular expression and string and returns all of the named capture group results in a map.
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// Note: this is only for the first match in the regex.
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func MatchNamedCaptureGroups(regEx *regexp.Regexp, content string) map[string]string {
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// note: we are looking across all matches and stopping on the first non-empty match. Why? Take the following example:
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// input: "cool something to match against" pattern: `((?P<name>match) (?P<version>against))?`. Since the pattern is
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// encapsulated in an optional capture group, there will be results for each character, but the results will match
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// on nothing. The only "true" match will be at the end ("match against").
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allMatches := regEx.FindAllStringSubmatch(content, -1)
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for matchIdx, match := range allMatches {
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// fill a candidate results map with named capture group results, accepting empty values, but not groups with
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// no names
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results := make(map[string]string)
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for nameIdx, name := range regEx.SubexpNames() {
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if nameIdx <= len(match) && len(name) > 0 {
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results[name] = match[nameIdx]
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}
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}
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// note: since we are looking for the first best potential match we should stop when we find the first one
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// with non-empty results.
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if len(results) > 0 {
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foundNonEmptyValue := false
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for _, value := range results {
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if value != "" {
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foundNonEmptyValue = true
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break
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}
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}
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// return the first non-empty result, or if this is the last match, the results that were found.
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if foundNonEmptyValue || matchIdx == len(allMatches)-1 {
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return results
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}
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}
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}
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return nil
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}
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