Remove isFuncType and ifaceOf helper funcs

They're incredibly simple now, so inline their only uses.

cache.go

@@ -9,21 +9,13 @@ import (
 )
 
 type pkgTypes struct {
-	ifaces map[string]string
-	funcs  map[string]bool
-}
-
-func (p *pkgTypes) isFuncType(t string) bool {
-	return p.funcs[t]
-}
-
-func (p *pkgTypes) ifaceOf(t string) string {
-	return p.ifaces[t]
+	ifaces    map[string]string
+	funcSigns map[string]bool
 }
 
 func (p *pkgTypes) getTypes(pkg *types.Package) {
 	p.ifaces = make(map[string]string)
-	p.funcs = make(map[string]bool)
+	p.funcSigns = make(map[string]bool)
 	addTypes := func(impPath string, ifs map[string]string, funs map[string]bool, top bool) {
 		fullName := func(name string) string {
 			if !top {
@@ -39,7 +31,7 @@ func (p *pkgTypes) getTypes(pkg *types.Package) {
 		}
 		for ftype := range funs {
 			// ignore non-exported func signatures too
-			p.funcs[ftype] = true
+			p.funcSigns[ftype] = true
 		}
 	}
 	for _, imp := range pkg.Imports() {

check.go

@@ -50,7 +50,7 @@ func (v *visitor) interfaceMatching(param *types.Var, usage *varUsage) (string,
 	called := make(map[string]string, len(usage.calls))
 	allCalls(usage, called, ftypes)
 	s := funcMapString(called)
-	return v.ifaceOf(s), s
+	return v.ifaces[s], s
 }
 
 type varUsage struct {
@@ -239,11 +239,6 @@ func (v *visitor) comparedWith(e, with ast.Expr) {
 	}
 }
 
-func (v *visitor) implementsIface(sign *types.Signature) bool {
-	s := signString(sign)
-	return v.isFuncType(s)
-}
-
 func (v *visitor) Visit(node ast.Node) ast.Visitor {
 	var fd *funcDecl
 	switch x := node.(type) {
@@ -253,7 +248,8 @@ func (v *visitor) Visit(node ast.Node) ast.Visitor {
 			sign:    v.Defs[x.Name].Type().(*types.Signature),
 			astType: x.Type,
 		}
-		if v.implementsIface(fd.sign) {
+		if v.funcSigns[signString(fd.sign)] {
+			// implements interface
 			return nil
 		}
 	case *ast.SelectorExpr: