Add path matcher.

editorconfig/path_matcher.go

@@ -0,0 +1,75 @@
+package editorconfig
+
+/*
+ * Converts a string from a .editorconfig file to a Go-compatible regex, according to the rules
+ * documented under "Wildcard Patterns" here:
+ * http://docs.editorconfig.org/en/master/editorconfig-format.html#patterns
+ *
+ * *	Matches any string of characters, except path separators (/)
+ * **	Matches any string of characters
+ * ?	Matches any single character
+ * [seq]	Matches any single character in seq
+ * [!seq]	Matches any single character not in seq
+ * {s1,s2,s3}	Matches any of the strings given (separated by commas, can be nested)
+ * {num1..num2}	Matches any integer numbers between num1 and num2, where num1 and num2 can be either positive or negative
+ */
+
+import (
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var metaCharsRegexp = []*regexp.Regexp{
+	// Characters .+$^!()
+	regexp.MustCompile(`([\.\+\$\^\!\(\)])`),
+	// [ not followed by a ]
+	regexp.MustCompile(`(\[[^\]]*)$`),
+	// ] not preceded by a [
+	regexp.MustCompile(`^([^\[]*\])`),
+}
+
+func ConvertWildcardPatternToGoRegexp(pattern string) *regexp.Regexp {
+	originalPattern := pattern
+
+	for _, r := range metaCharsRegexp {
+		pattern = r.ReplaceAllString(pattern, "\\$1")
+	}
+
+	// Handle **
+	pattern = strings.Replace(pattern, `**`, `.+`, -1)
+
+	// Handle *
+	pattern = strings.Replace(pattern, `*`, `[^/\\]+`, -1)
+
+	// Handle ?
+	pattern = strings.Replace(pattern, `?`, `.`, -1)
+
+	// [seq] should work already.
+
+	// Handle [!seq]
+	pattern = strings.Replace(pattern, `[\!`, `[^`, -1)
+
+	// Handle {s1,s2,s3}
+	for i := 1; i < 7; i++ {
+		find := `\{([^,}]+)` + strings.Repeat(`,([^,}]+)`, i) + `\}`
+		replace := "($1"
+		for ii := 1; ii <= i; ii++ {
+			replace += "|$" + strconv.Itoa(ii+1)
+		}
+		replace += ")"
+		pattern = regexp.MustCompile(find).ReplaceAllString(pattern, replace)
+	}
+
+	// Handle {num1..num2}
+	// @todo - This is currently not fully supported. If there is a numeric range, we only check
+	// that numbers are present; we don't check if the numbers present are within the correct range.
+	pattern = regexp.MustCompile(`\{-?\d+\\.\\.-?\d+\}`).ReplaceAllString(pattern, `[-0-9]+`)
+
+	r, err := regexp.Compile(pattern)
+	if err != nil {
+		ExitBecauseOfInternalError("A file pattern could not be parsed: " + originalPattern)
+	}
+
+	return r
+}