Apply more golint recommendations (#201)

* Apply more golint recommendations

* Update dumpstdlibast.go to include StdAst comment

* Improve dump.go package comment.

Author: marcelocantos

Diff for: ast/ast.go

@@ -14,6 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package ast provides AST nodes and ancillary structures and algorithms.
 package ast
 
 import (

Diff for: ast/stdast.go

@@ -1,3 +1,10 @@
+///////////////////////////////////////////////////////////
+// This file was auto-generated by cmd/dumpstdlibast.go. //
+// https://github.com/google/go-jsonnet#generated-stdlib //
+//                                                       //
+// --------------- DO NOT EDIT BY HAND! ---------------  //
+///////////////////////////////////////////////////////////
+
 package ast
 
 var p3Var = "$"
@@ -2768,6 +2775,8 @@ var p1 = &Source{
 		"\n",
 	},
 }
+
+// StdAst is the AST for the standard library.
 var StdAst = &DesugaredObject{
 	NodeBase: NodeBase{
 		loc: LocationRange{

Diff for: ast/util.go

@@ -18,16 +18,17 @@ package ast
 
 import "sort"
 
-func (i *IdentifierSet) Append(idents Identifiers) {
+// AddIdentifiers adds a slice of identifiers to an identifier set.
+func (i IdentifierSet) AddIdentifiers(idents Identifiers) {
 	for _, ident := range idents {
 		i.Add(ident)
 	}
 }
 
-// ToOrderedSlice returns the elements of the current set as a ordered slice
-func (set IdentifierSet) ToOrderedSlice() []Identifier {
+// ToOrderedSlice returns the elements of the current set as an ordered slice.
+func (i IdentifierSet) ToOrderedSlice() []Identifier {
 	var s []Identifier
-	for v := range set {
+	for v := range i {
 		s = append(s, v)
 	}
 	sort.Sort(identifierSorter(s))

Diff for: cmd/dumpstdlibast.go

@@ -43,9 +43,22 @@ func main() {
 	dump.Config.HidePrivateFields = false
 	dump.Config.StripPackageNames = true
 	dump.Config.VariableName = "StdAst"
+	dump.Config.VariableDescription = "StdAst is the AST for the standard library."
 	ast := dump.Sdump(node)
 
-	file.WriteString("package ast\n\n")
+	file.WriteString(header)
 	file.WriteString(ast)
-	file.Sync()
+	file.Close()
 }
+
+var header = `
+///////////////////////////////////////////////////////////
+// This file was auto-generated by cmd/dumpstdlibast.go. //
+// https://github.com/google/go-jsonnet#generated-stdlib //
+//                                                       //
+// --------------- DO NOT EDIT BY HAND! ---------------  //
+///////////////////////////////////////////////////////////
+
+package ast
+
+`[1:]

Diff for: dump/dump.go

@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package dump can dump a Go data structure to Go source file, so that it can
+// be statically embedded into other code.
 package dump
 
 import (
@@ -31,17 +33,19 @@ var packageNameStripperRegexp = regexp.MustCompile("\\b[a-zA-Z_]+[a-zA-Z_0-9]+\\
 
 // Options represents configuration option
 type Options struct {
-	StripPackageNames bool
-	HidePrivateFields bool
-	HomePackage       string
-	VariableName      string
+	StripPackageNames   bool
+	HidePrivateFields   bool
+	HomePackage         string
+	VariableName        string
+	VariableDescription string
 }
 
 // Config is the default config used when calling Dump
 var Config = Options{
-	StripPackageNames: false,
-	HidePrivateFields: true,
-	VariableName:      "Obj",
+	StripPackageNames:   false,
+	HidePrivateFields:   true,
+	VariableName:        "Obj",
+	VariableDescription: "",
 }
 
 type dumpState struct {
@@ -157,8 +161,15 @@ func (s *dumpState) dumpMap(v reflect.Value) {
 }
 
 func (s *dumpState) dump(value interface{}) {
-	if value == nil {
+	writeVar := func() {
+		if s.config.VariableDescription != "" {
+			fmt.Fprintf(s.w, "\n// %s\n", s.config.VariableDescription)
+		}
 		s.w.Write([]byte("var " + s.config.VariableName + " = "))
+	}
+
+	if value == nil {
+		writeVar()
 		printNil(s.w)
 		s.newline()
 		return
@@ -170,7 +181,7 @@ func (s *dumpState) dump(value interface{}) {
 
 	s.dumpReusedPointerVal(v)
 
-	s.w.Write([]byte("var " + s.config.VariableName + " = "))
+	writeVar()
 	if v.Kind() == reflect.Ptr && v.IsNil() {
 		printNil(s.w)
 	} else {

Diff for: dump/pointermap.go

@@ -24,8 +24,8 @@ type pointerMap struct {
 	primitivePointers []uintptr
 }
 
-// GetPointers: Given a structure, it will recursively map all pointers mentioned in the tree,
-// breaking circular references and provide list of:
+// GetPointers recursively maps all pointers mentioned in a tree, breaking
+// circular references, and provides a list of:
 // * all pointers
 // * all pointers that were referenced at least twice
 // * all pointers that point to primitive type

Diff for: jsonnet/cmd.go

@@ -120,21 +120,21 @@ func usage(o io.Writer) {
 func safeStrToInt(str string) (i int) {
 	i, err := strconv.Atoi(str)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "ERROR: Invalid integer \"%s\"\n", str)
+		fmt.Fprintf(os.Stderr, "Invalid integer \"%s\"\n", str)
 		os.Exit(1)
 	}
 	return
 }
 
-type Command int
+type command int
 
 const (
 	commandEval = iota
 	commandFmt  = iota
 )
 
 type config struct {
-	cmd            Command
+	cmd            command
 	inputFiles     []string
 	outputFile     string
 	filenameIsCode bool
@@ -167,20 +167,18 @@ func getVarVal(s string) (string, string, error) {
 		if exists {
 			return name, content, nil
 		}
-		return "", "", fmt.Errorf("ERROR: Environment variable %v was undefined.", name)
-	} else {
-		return name, parts[1], nil
+		return "", "", fmt.Errorf("environment variable %v was undefined", name)
 	}
+	return name, parts[1], nil
 }
 
 func getVarFile(s string, imp string) (string, string, error) {
 	parts := strings.SplitN(s, "=", 2)
 	name := parts[0]
 	if len(parts) == 1 {
-		return "", "", fmt.Errorf("ERROR: argument not in form <var>=<file> \"%s\".", s)
-	} else {
-		return name, fmt.Sprintf("%s @'%s'", imp, strings.Replace(parts[1], "'", "''", -1)), nil
+		return "", "", fmt.Errorf(`argument not in form <var>=<file> "%s"`, s)
 	}
+	return name, fmt.Sprintf("%s @'%s'", imp, strings.Replace(parts[1], "'", "''", -1)), nil
 }
 
 type processArgsStatus int
@@ -217,7 +215,7 @@ func processArgs(givenArgs []string, config *config, vm *jsonnet.VM) (processArg
 		} else if arg == "-o" || arg == "--output-file" {
 			outputFile := nextArg(&i, args)
 			if len(outputFile) == 0 {
-				return processArgsStatusFailure, fmt.Errorf("ERROR: -o argument was empty string")
+				return processArgsStatusFailure, fmt.Errorf("-o argument was empty string")
 			}
 			config.outputFile = outputFile
 		} else if arg == "--" {
@@ -231,13 +229,13 @@ func processArgs(givenArgs []string, config *config, vm *jsonnet.VM) (processArg
 			if arg == "-s" || arg == "--max-stack" {
 				l := safeStrToInt(nextArg(&i, args))
 				if l < 1 {
-					return processArgsStatusFailure, fmt.Errorf("ERROR: Invalid --max-stack value: %d", l)
+					return processArgsStatusFailure, fmt.Errorf("invalid --max-stack value: %d", l)
 				}
 				vm.MaxStack = l
 			} else if arg == "-J" || arg == "--jpath" {
 				dir := nextArg(&i, args)
 				if len(dir) == 0 {
-					return processArgsStatusFailure, fmt.Errorf("ERROR: -J argument was empty string")
+					return processArgsStatusFailure, fmt.Errorf("-J argument was empty string")
 				}
 				if dir[len(dir)-1] != '/' {
 					dir += "/"
@@ -302,14 +300,14 @@ func processArgs(givenArgs []string, config *config, vm *jsonnet.VM) (processArg
 			} else if arg == "-t" || arg == "--max-trace" {
 				l := safeStrToInt(nextArg(&i, args))
 				if l < 0 {
-					return processArgsStatusFailure, fmt.Errorf("ERROR: Invalid --max-trace value: %d", l)
+					return processArgsStatusFailure, fmt.Errorf("invalid --max-trace value: %d", l)
 				}
 				vm.ErrorFormatter.SetMaxStackTraceSize(l)
 			} else if arg == "-m" || arg == "--multi" {
 				config.evalMulti = true
 				outputDir := nextArg(&i, args)
 				if len(outputDir) == 0 {
-					return processArgsStatusFailure, fmt.Errorf("ERROR: -m argument was empty string")
+					return processArgsStatusFailure, fmt.Errorf("-m argument was empty string")
 				}
 				if outputDir[len(outputDir)-1] != '/' {
 					outputDir += "/"
@@ -320,13 +318,12 @@ func processArgs(givenArgs []string, config *config, vm *jsonnet.VM) (processArg
 			} else if arg == "-S" || arg == "--string" {
 				vm.StringOutput = true
 			} else if len(arg) > 1 && arg[0] == '-' {
-				return processArgsStatusFailure, fmt.Errorf("ERROR: Unrecognized argument: %s", arg)
+				return processArgsStatusFailure, fmt.Errorf("unrecognized argument: %s", arg)
 			} else {
 				remainingArgs = append(remainingArgs, arg)
 			}
-
 		} else {
-			return processArgsStatusFailure, fmt.Errorf("The Go implementation currently does not support jsonnet fmt.")
+			return processArgsStatusFailure, fmt.Errorf("the Go implementation currently does not support jsonnet fmt")
 		}
 	}
 
@@ -335,15 +332,15 @@ func processArgs(givenArgs []string, config *config, vm *jsonnet.VM) (processArg
 		want = "code"
 	}
 	if len(remainingArgs) == 0 {
-		return processArgsStatusFailureUsage, fmt.Errorf("ERROR: Must give %s", want)
+		return processArgsStatusFailureUsage, fmt.Errorf("must give %s", want)
 	}
 
 	// TODO(dcunnin): Formatter allows multiple files in test and in-place mode.
 	multipleFilesAllowed := false
 
 	if !multipleFilesAllowed {
 		if len(remainingArgs) > 1 {
-			return processArgsStatusFailure, fmt.Errorf("ERROR: Only one %s is allowed", want)
+			return processArgsStatusFailure, fmt.Errorf("only one %s is allowed", want)
 		}
 	}
 
@@ -390,7 +387,7 @@ func writeMultiOutputFiles(output map[string]string, outputDir, outputFile strin
 
 	// Iterate through the map in order.
 	keys := make([]string, 0, len(output))
-	for k, _ := range output {
+	for k := range output {
 		keys = append(keys, k)
 	}
 	sort.Strings(keys)
@@ -511,7 +508,7 @@ func main() {
 
 	status, err := processArgs(os.Args[1:], &config, vm)
 	if err != nil {
-		fmt.Fprintln(os.Stderr, err.Error())
+		fmt.Fprintln(os.Stderr, "ERROR: "+err.Error())
 	}
 	switch status {
 	case processArgsStatusContinue:

Diff for: linter/linter.go

@@ -1,3 +1,4 @@
+// Package linter analyses Jsonnet code for code "smells".
 package linter
 
 import (

Diff for: parser/parser.go

@@ -14,6 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+// Package parser reads Jsonnet files and parses them into AST nodes.
 package parser
 
 import (

Diff for: static_analyzer.go

@@ -33,7 +33,7 @@ func visitNext(a ast.Node, inObject bool, vars ast.IdentifierSet, state *analysi
 		return
 	}
 	state.err = analyzeVisit(a, inObject, vars)
-	state.freeVars.Append(a.FreeVariables())
+	state.freeVars.AddIdentifiers(a.FreeVariables())
 }
 
 func analyzeVisit(a ast.Node, inObject bool, vars ast.IdentifierSet) error {