Add ability to compile a pattern

doublestar_test.go

@@ -236,6 +236,36 @@ func TestMatch(t *testing.T) {
 	}
 }
 
+func TestCompile(t *testing.T) {
+	for idx, tt := range matchTests {
+		testCompileWith(t, idx, tt)
+	}
+}
+
+func testCompileWith(t *testing.T, idx int, tt MatchTest) {
+	defer func() {
+		if r := recover(); r != nil {
+			t.Errorf("#%v. Match(%#q, %#q) panicked: %#v", idx, tt.pattern, tt.testPath, r)
+		}
+	}()
+
+	ok := false
+	pat, err := Compile(tt.pattern)
+	if err == nil {
+		ok = pat.Match(tt.testPath)
+	}
+	if ok != tt.shouldMatch || err != tt.expectedErr {
+		t.Errorf("#%v. Match(%#q, %#q) = %v, %v want %v, %v", idx, tt.pattern, tt.testPath, ok, err, tt.shouldMatch, tt.expectedErr)
+	}
+
+	if tt.isStandard {
+		stdOk, stdErr := path.Match(tt.pattern, tt.testPath)
+		if ok != stdOk || !compareErrors(err, stdErr) {
+			t.Errorf("#%v. Match(%#q, %#q) != path.Match(...). Got %v, %v want %v, %v", idx, tt.pattern, tt.testPath, ok, err, stdOk, stdErr)
+		}
+	}
+}
+
 func testMatchWith(t *testing.T, idx int, tt MatchTest) {
 	defer func() {
 		if r := recover(); r != nil {

match.go

@@ -89,6 +89,39 @@ func PathMatchUnvalidated(pattern, name string) bool {
 	return matched
 }
 
+// Pattern is a representation of a compiled glob pattern.
+type Pattern struct {
+	// initial implementation doesn't actually "compile", just saves the pattern to use when matching
+	// Obviously long term we'll want to store some kind of tree or something
+	pattern string
+}
+
+// Compile parses a pattern and returns, if successful, a [Pattern] object
+// that can be used to match against text.
+func Compile(pattern string) (*Pattern, error) {
+	if !ValidatePattern(pattern) {
+		return nil, ErrBadPattern
+	}
+	return &Pattern{
+		pattern: pattern,
+	}, nil
+}
+
+// MustCompile is like Compile but panics if the expression cannot be parsed.
+func MustCompile(pattern string) *Pattern {
+
+	p, err := Compile(pattern)
+	if err != nil {
+		panic(err)
+	}
+	return p
+}
+
+// Match reports whether the name matches this pattern
+func (p *Pattern) Match(name string) bool {
+	return MatchUnvalidated(p.pattern, name)
+}
+
 func matchWithSeparator(pattern, name string, separator rune, validate bool) (matched bool, err error) {
 	return doMatchWithSeparator(pattern, name, separator, validate, -1, -1, -1, -1, 0, 0)
 }