pattern: support Mode in all APIs

And document the type.

This is perhaps the last remaining API change that was planned for v3.

expand/expand.go

@@ -159,6 +159,8 @@ func Document(cfg *Config, word *syntax.Word) (string, error) {
 	return cfg.fieldJoin(field), nil
 }
 
+const patMode = pattern.Filenames | pattern.Braces
+
 // Pattern expands a single shell word as a pattern, using syntax.QuotePattern
 // on any non-quoted parts of the input word. The result can be used on
 // syntax.TranslatePattern directly.
@@ -174,7 +176,7 @@ func Pattern(cfg *Config, word *syntax.Word) (string, error) {
 	buf := cfg.strBuilder()
 	for _, part := range field {
 		if part.quote > quoteNone {
-			buf.WriteString(pattern.QuoteMeta(part.val))
+			buf.WriteString(pattern.QuoteMeta(part.val, patMode))
 		} else {
 			buf.WriteString(part.val)
 		}
@@ -345,11 +347,11 @@ func (cfg *Config) escapedGlobField(parts []fieldPart) (escaped string, glob boo
 	buf := cfg.strBuilder()
 	for _, part := range parts {
 		if part.quote > quoteNone {
-			buf.WriteString(pattern.QuoteMeta(part.val))
+			buf.WriteString(pattern.QuoteMeta(part.val, patMode))
 			continue
 		}
 		buf.WriteString(part.val)
-		if pattern.HasMeta(part.val) {
+		if pattern.HasMeta(part.val, patMode) {
 			glob = true
 		}
 	}

pattern/example_test.go

@@ -32,12 +32,13 @@ func ExampleRegexp() {
 
 func ExampleQuoteMeta() {
 	pat := "foo?bar*"
+	const mode = 0
 	fmt.Println(pat)
 
-	quoted := pattern.QuoteMeta(pat)
+	quoted := pattern.QuoteMeta(pat, mode)
 	fmt.Println(quoted)
 
-	expr, err := pattern.Regexp(quoted, 0)
+	expr, err := pattern.Regexp(quoted, mode)
 	if err != nil {
 		return
 	}

pattern/pattern.go

@@ -16,8 +16,8 @@ import (
 	"strings"
 )
 
-// TODO: support Mode in the other APIs too
-
+// Mode can be used to supply a number of options to the package's functions.
+// Not all functions change their behavior with all of the options below.
 type Mode uint
 
 const (
@@ -254,13 +254,17 @@ func charClass(s string) (string, error) {
 // This can be useful to avoid extra work, like TranslatePattern. Note that this
 // function cannot be used to avoid QuotePattern, as backslashes are quoted by
 // that function but ignored here.
-func HasMeta(pat string) bool {
+func HasMeta(pat string, mode Mode) bool {
 	for i := 0; i < len(pat); i++ {
 		switch pat[i] {
 		case '\\':
 			i++
 		case '*', '?', '[':
 			return true
+		case '{':
+			if mode&Braces != 0 {
+				return true
+			}
 		}
 	}
 	return false
@@ -270,11 +274,16 @@ func HasMeta(pat string) bool {
 // given text. The returned string is a pattern that matches the literal text.
 //
 // For example, QuoteMeta(`foo*bar?`) returns `foo\*bar\?`.
-func QuoteMeta(pat string) string {
+func QuoteMeta(pat string, mode Mode) string {
 	any := false
 loop:
 	for _, r := range pat {
 		switch r {
+		case '{':
+			if mode&Braces == 0 {
+				continue
+			}
+			fallthrough
 		case '*', '?', '[', '\\':
 			any = true
 			break loop
@@ -288,6 +297,10 @@ loop:
 		switch r {
 		case '*', '?', '[', '\\':
 			buf.WriteByte('\\')
+		case '{':
+			if mode&Braces != 0 {
+				buf.WriteByte('\\')
+			}
 		}
 		buf.WriteRune(r)
 	}

pattern/pattern_test.go

@@ -108,27 +108,31 @@ func TestRegexp(t *testing.T) {
 
 var metaTests = []struct {
 	pat       string
+	mode      Mode
 	wantHas   bool
 	wantQuote string
 }{
-	{``, false, ``},
-	{`foo`, false, `foo`},
-	{`.`, false, `.`},
-	{`*`, true, `\*`},
-	{`foo?`, true, `foo\?`},
-	{`\[`, false, `\\\[`},
+	{``, 0, false, ``},
+	{`foo`, 0, false, `foo`},
+	{`.`, 0, false, `.`},
+	{`*`, 0, true, `\*`},
+	{`*`, Shortest | Filenames, true, `\*`},
+	{`foo?`, 0, true, `foo\?`},
+	{`\[`, 0, false, `\\\[`},
+	{`{`, 0, false, `{`},
+	{`{`, Braces, true, `\{`},
 }
 
 func TestMeta(t *testing.T) {
 	t.Parallel()
 	for _, tc := range metaTests {
-		if got := HasMeta(tc.pat); got != tc.wantHas {
-			t.Errorf("HasMeta(%q) got %t, wanted %t",
-				tc.pat, got, tc.wantHas)
+		if got := HasMeta(tc.pat, tc.mode); got != tc.wantHas {
+			t.Errorf("HasMeta(%q, %b) got %t, wanted %t",
+				tc.pat, tc.mode, got, tc.wantHas)
 		}
-		if got := QuoteMeta(tc.pat); got != tc.wantQuote {
-			t.Errorf("QuoteMeta(%q) got %q, wanted %q",
-				tc.pat, got, tc.wantQuote)
+		if got := QuoteMeta(tc.pat, tc.mode); got != tc.wantQuote {
+			t.Errorf("QuoteMeta(%q, %b) got %q, wanted %q",
+				tc.pat, tc.mode, got, tc.wantQuote)
 		}
 	}
 }