refactor routeRegexp, particularily newRouteRegexp. (#328)

The existing options matchPrefix, matchHost, and matchQueries are
mutually exclusive so there's no point in having a separate boolean
argument for each one. It's clearer if there's a single type variable.

strictSlash and useEncodedPath were also being passed as naked bools so
I've wrapped these in a struct called routeRegexpOptions for more clarity
at the call site.

mux_test.go

@@ -25,7 +25,7 @@ func (r *Route) GoString() string {
 }
 
 func (r *routeRegexp) GoString() string {
-	return fmt.Sprintf("&routeRegexp{template: %q, matchHost: %t, matchQuery: %t, strictSlash: %t, regexp: regexp.MustCompile(%q), reverse: %q, varsN: %v, varsR: %v", r.template, r.matchHost, r.matchQuery, r.strictSlash, r.regexp.String(), r.reverse, r.varsN, r.varsR)
+	return fmt.Sprintf("&routeRegexp{template: %q, regexpType: %v, options: %v, regexp: regexp.MustCompile(%q), reverse: %q, varsN: %v, varsR: %v", r.template, r.regexpType, r.options, r.regexp.String(), r.reverse, r.varsN, r.varsR)
 }
 
 type routeTest struct {

old_test.go

@@ -681,7 +681,7 @@ func TestNewRegexp(t *testing.T) {
 	}
 
 	for pattern, paths := range tests {
-		p, _ = newRouteRegexp(pattern, false, false, false, false, false)
+		p, _ = newRouteRegexp(pattern, regexpTypePath, routeRegexpOptions{})
 		for path, result := range paths {
 			matches = p.regexp.FindStringSubmatch(path)
 			if result == nil {

regexp.go

@@ -14,6 +14,20 @@ import (
 	"strings"
 )
 
+type routeRegexpOptions struct {
+	strictSlash    bool
+	useEncodedPath bool
+}
+
+type regexpType int
+
+const (
+	regexpTypePath   regexpType = 0
+	regexpTypeHost   regexpType = 1
+	regexpTypePrefix regexpType = 2
+	regexpTypeQuery  regexpType = 3
+)
+
 // newRouteRegexp parses a route template and returns a routeRegexp,
 // used to match a host, a path or a query string.
 //
@@ -24,7 +38,7 @@ import (
 // Previously we accepted only Python-like identifiers for variable
 // names ([a-zA-Z_][a-zA-Z0-9_]*), but currently the only restriction is that
 // name and pattern can't be empty, and names can't contain a colon.
-func newRouteRegexp(tpl string, matchHost, matchPrefix, matchQuery, strictSlash, useEncodedPath bool) (*routeRegexp, error) {
+func newRouteRegexp(tpl string, typ regexpType, options routeRegexpOptions) (*routeRegexp, error) {
 	// Check if it is well-formed.
 	idxs, errBraces := braceIndices(tpl)
 	if errBraces != nil {
@@ -34,19 +48,18 @@ func newRouteRegexp(tpl string, matchHost, matchPrefix, matchQuery, strictSlash,
 	template := tpl
 	// Now let's parse it.
 	defaultPattern := "[^/]+"
-	if matchQuery {
+	if typ == regexpTypeQuery {
 		defaultPattern = ".*"
-	} else if matchHost {
+	} else if typ == regexpTypeHost {
 		defaultPattern = "[^.]+"
-		matchPrefix = false
 	}
 	// Only match strict slash if not matching
-	if matchPrefix || matchHost || matchQuery {
-		strictSlash = false
+	if typ != regexpTypePath {
+		options.strictSlash = false
 	}
 	// Set a flag for strictSlash.
 	endSlash := false
-	if strictSlash && strings.HasSuffix(tpl, "/") {
+	if options.strictSlash && strings.HasSuffix(tpl, "/") {
 		tpl = tpl[:len(tpl)-1]
 		endSlash = true
 	}
@@ -88,16 +101,16 @@ func newRouteRegexp(tpl string, matchHost, matchPrefix, matchQuery, strictSlash,
 	// Add the remaining.
 	raw := tpl[end:]
 	pattern.WriteString(regexp.QuoteMeta(raw))
-	if strictSlash {
+	if options.strictSlash {
 		pattern.WriteString("[/]?")
 	}
-	if matchQuery {
+	if typ == regexpTypeQuery {
 		// Add the default pattern if the query value is empty
 		if queryVal := strings.SplitN(template, "=", 2)[1]; queryVal == "" {
 			pattern.WriteString(defaultPattern)
 		}
 	}
-	if !matchPrefix {
+	if typ != regexpTypePrefix {
 		pattern.WriteByte('$')
 	}
 	reverse.WriteString(raw)
@@ -118,15 +131,13 @@ func newRouteRegexp(tpl string, matchHost, matchPrefix, matchQuery, strictSlash,
 
 	// Done!
 	return &routeRegexp{
-		template:       template,
-		matchHost:      matchHost,
-		matchQuery:     matchQuery,
-		strictSlash:    strictSlash,
-		useEncodedPath: useEncodedPath,
-		regexp:         reg,
-		reverse:        reverse.String(),
-		varsN:          varsN,
-		varsR:          varsR,
+		template:   template,
+		regexpType: typ,
+		options:    options,
+		regexp:     reg,
+		reverse:    reverse.String(),
+		varsN:      varsN,
+		varsR:      varsR,
 	}, nil
 }
 
@@ -135,15 +146,10 @@ func newRouteRegexp(tpl string, matchHost, matchPrefix, matchQuery, strictSlash,
 type routeRegexp struct {
 	// The unmodified template.
 	template string
-	// True for host match, false for path or query string match.
-	matchHost bool
-	// True for query string match, false for path and host match.
-	matchQuery bool
-	// The strictSlash value defined on the route, but disabled if PathPrefix was used.
-	strictSlash bool
-	// Determines whether to use encoded req.URL.EnscapedPath() or unencoded
-	// req.URL.Path for path matching
-	useEncodedPath bool
+	// The type of match
+	regexpType regexpType
+	// Options for matching
+	options routeRegexpOptions
 	// Expanded regexp.
 	regexp *regexp.Regexp
 	// Reverse template.
@@ -156,12 +162,12 @@ type routeRegexp struct {
 
 // Match matches the regexp against the URL host or path.
 func (r *routeRegexp) Match(req *http.Request, match *RouteMatch) bool {
-	if !r.matchHost {
-		if r.matchQuery {
+	if r.regexpType != regexpTypeHost {
+		if r.regexpType == regexpTypeQuery {
 			return r.matchQueryString(req)
 		}
 		path := req.URL.Path
-		if r.useEncodedPath {
+		if r.options.useEncodedPath {
 			path = req.URL.EscapedPath()
 		}
 		return r.regexp.MatchString(path)
@@ -178,7 +184,7 @@ func (r *routeRegexp) url(values map[string]string) (string, error) {
 		if !ok {
 			return "", fmt.Errorf("mux: missing route variable %q", v)
 		}
-		if r.matchQuery {
+		if r.regexpType == regexpTypeQuery {
 			value = url.QueryEscape(value)
 		}
 		urlValues[k] = value
@@ -203,7 +209,7 @@ func (r *routeRegexp) url(values map[string]string) (string, error) {
 // For a URL with foo=bar&baz=ding, we return only the relevant key
 // value pair for the routeRegexp.
 func (r *routeRegexp) getURLQuery(req *http.Request) string {
-	if !r.matchQuery {
+	if r.regexpType != regexpTypeQuery {
 		return ""
 	}
 	templateKey := strings.SplitN(r.template, "=", 2)[0]
@@ -280,7 +286,7 @@ func (v *routeRegexpGroup) setMatch(req *http.Request, m *RouteMatch, r *Route)
 		if len(matches) > 0 {
 			extractVars(path, matches, v.path.varsN, m.Vars)
 			// Check if we should redirect.
-			if v.path.strictSlash {
+			if v.path.options.strictSlash {
 				p1 := strings.HasSuffix(path, "/")
 				p2 := strings.HasSuffix(v.path.template, "/")
 				if p1 != p2 {

route.go

@@ -171,12 +171,12 @@ func (r *Route) addMatcher(m matcher) *Route {
 }
 
 // addRegexpMatcher adds a host or path matcher and builder to a route.
-func (r *Route) addRegexpMatcher(tpl string, matchHost, matchPrefix, matchQuery bool) error {
+func (r *Route) addRegexpMatcher(tpl string, typ regexpType) error {
 	if r.err != nil {
 		return r.err
 	}
 	r.regexp = r.getRegexpGroup()
-	if !matchHost && !matchQuery {
+	if typ == regexpTypePath || typ == regexpTypePrefix {
 		if len(tpl) > 0 && tpl[0] != '/' {
 			return fmt.Errorf("mux: path must start with a slash, got %q", tpl)
 		}
@@ -184,7 +184,10 @@ func (r *Route) addRegexpMatcher(tpl string, matchHost, matchPrefix, matchQuery
 			tpl = strings.TrimRight(r.regexp.path.template, "/") + tpl
 		}
 	}
-	rr, err := newRouteRegexp(tpl, matchHost, matchPrefix, matchQuery, r.strictSlash, r.useEncodedPath)
+	rr, err := newRouteRegexp(tpl, typ, routeRegexpOptions{
+		strictSlash:    r.strictSlash,
+		useEncodedPath: r.useEncodedPath,
+	})
 	if err != nil {
 		return err
 	}
@@ -193,7 +196,7 @@ func (r *Route) addRegexpMatcher(tpl string, matchHost, matchPrefix, matchQuery
 			return err
 		}
 	}
-	if matchHost {
+	if typ == regexpTypeHost {
 		if r.regexp.path != nil {
 			if err = uniqueVars(rr.varsN, r.regexp.path.varsN); err != nil {
 				return err
@@ -206,7 +209,7 @@ func (r *Route) addRegexpMatcher(tpl string, matchHost, matchPrefix, matchQuery
 				return err
 			}
 		}
-		if matchQuery {
+		if typ == regexpTypeQuery {
 			r.regexp.queries = append(r.regexp.queries, rr)
 		} else {
 			r.regexp.path = rr
@@ -289,7 +292,7 @@ func (r *Route) HeadersRegexp(pairs ...string) *Route {
 // Variable names must be unique in a given route. They can be retrieved
 // calling mux.Vars(request).
 func (r *Route) Host(tpl string) *Route {
-	r.err = r.addRegexpMatcher(tpl, true, false, false)
+	r.err = r.addRegexpMatcher(tpl, regexpTypeHost)
 	return r
 }
 
@@ -349,7 +352,7 @@ func (r *Route) Methods(methods ...string) *Route {
 // Variable names must be unique in a given route. They can be retrieved
 // calling mux.Vars(request).
 func (r *Route) Path(tpl string) *Route {
-	r.err = r.addRegexpMatcher(tpl, false, false, false)
+	r.err = r.addRegexpMatcher(tpl, regexpTypePath)
 	return r
 }
 
@@ -365,7 +368,7 @@ func (r *Route) Path(tpl string) *Route {
 // Also note that the setting of Router.StrictSlash() has no effect on routes
 // with a PathPrefix matcher.
 func (r *Route) PathPrefix(tpl string) *Route {
-	r.err = r.addRegexpMatcher(tpl, false, true, false)
+	r.err = r.addRegexpMatcher(tpl, regexpTypePrefix)
 	return r
 }
 
@@ -396,7 +399,7 @@ func (r *Route) Queries(pairs ...string) *Route {
 		return nil
 	}
 	for i := 0; i < length; i += 2 {
-		if r.err = r.addRegexpMatcher(pairs[i]+"="+pairs[i+1], false, false, true); r.err != nil {
+		if r.err = r.addRegexpMatcher(pairs[i]+"="+pairs[i+1], regexpTypeQuery); r.err != nil {
 			return r
 		}
 	}