add documentation

pkg/gomod/gomod.go

@@ -7,26 +7,23 @@ import (
 	"golang.org/x/mod/modfile"
 )
 
-type logger interface {
-	Logf(f string, s ...interface{})
-	Debugf(f string, s ...interface{})
-}
-
+// GoMod represents a Go Modules parser.
+// Running LoadAndComputePairs with a filename will return a slice of parsed dependencies.
 type GoMod struct {
 	IncludeIndirect bool
 	ProxyLoader     Queryer
 	Logger          logger
 }
 
-func isReplaced(module string, replaces []*modfile.Replace) bool {
-	for i := range replaces {
-		if module == replaces[i].Old.Path {
-			return true
-		}
-	}
-	return false
+// logger is an extremely simple leveled logger
+type logger interface {
+	Logf(f string, s ...interface{})
+	Debugf(f string, s ...interface{})
 }
 
+// LoadAndComputePairs takes a filename of a go.mod file,
+// runs the resolution algorithm in the provided Querier,
+// and returns parsed pairs of dependencies and their latest versions.
 func (g *GoMod) LoadAndComputePairs(filename string) ([]libyear.Pair, error) {
 	b, err := os.ReadFile(filename)
 	if err != nil {
@@ -59,3 +56,12 @@ func (g *GoMod) LoadAndComputePairs(filename string) ([]libyear.Pair, error) {
 	}
 	return pairs, nil
 }
+
+func isReplaced(module string, replaces []*modfile.Replace) bool {
+	for i := range replaces {
+		if module == replaces[i].Old.Path {
+			return true
+		}
+	}
+	return false
+}