UPDATE FORMAT

Author: wamshawn

README.md

@@ -48,6 +48,12 @@ type Errors interface {
     if errors.Contains(e3, e1) {
         // TODO ...
     }
+
+    // full format
+    fmt.Println(fmt.Sprintf("%+v", e3))
+
+    // json format
+    fmt.Println(fmt.Sprintf("%-v", e3))
 ```
 
 [Read the examples for more usages.](https://github.com/pharosnet/errors/tree/master/example) 

errors.go

@@ -47,6 +47,30 @@ func WithF(cause error, format string, args ...interface{}) error {
 	}
 }
 
+func WithDepth(depth int, cause error, message string) error {
+	if cause == nil {
+		return nil
+	}
+	return &errorUp{
+		msg:      message,
+		cause:    cause,
+		pcs:      callersByAssigned(depth, 3),
+		occurred: timeNow(),
+	}
+}
+
+func WithDepthF(depth int, cause error, format string, args ...interface{}) error {
+	if cause == nil {
+		return nil
+	}
+	return &errorUp{
+		msg:      fmt.Sprintf(format, args...),
+		cause:    cause,
+		pcs:      callersByAssigned(depth, 3),
+		occurred: timeNow(),
+	}
+}
+
 func Wrap(e error) error {
 	return &errorUp{
 		msg:      e.Error(),

errors_test.go

@@ -0,0 +1,18 @@
+package errors_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/pharosnet/errors"
+)
+
+func TestErrorF(t *testing.T) {
+	e1 := errors.New("error 1")
+	e2 := errors.WithF(e1, "error %d", 2)
+	fmt.Println(fmt.Sprintf("%+v", e2))
+
+	e3 := errors.WithDepth(2, e2, "error 3")
+	fmt.Println(fmt.Sprintf("%-v", e3))
+
+}

format.go

@@ -13,31 +13,59 @@ func DefaultFormatFn(s fmt.State, verb rune, e Errors) {
 	case 'v':
 		switch {
 		case s.Flag('+'):
-			fmt.Fprintf(s, "%s\n", e.Error())
+			_, _ = fmt.Fprintf(s, "- %s\n", e.Error())
 			for i, pc := range e.PCS() {
 				fn := runtime.FuncForPC(pc)
 				if fn == nil {
-					io.WriteString(s, "unknown")
+					_, _ = io.WriteString(s, "unknown")
 				} else {
 					file, line := fn.FileLine(pc)
 					home, filename := fileName(file)
 					if i == 0 {
-						fmt.Fprintf(s, "\t[T] %s\n\t[F] %s\n\t[H] %s\n\t[F] %s:%d \n", e.OccurTime().String(), fn.Name(), home, filename, line)
+						_, _ = fmt.Fprintf(s, "\t[T] %s\n\t[F] %s\n\t[H] %s\n\t[F] %s:%d \n", e.OccurTime().String(), fn.Name(), home, filename, line)
 					} else {
-						fmt.Fprintf(s, "\t[F] %s\n\t[H] %s\n\t[F] %s:%d \n", fn.Name(), home, filename, line)
+						_, _ = fmt.Fprintf(s, "\t[F] %s\n\t[H] %s\n\t[F] %s:%d \n", fn.Name(), home, filename, line)
 					}
 				}
 			}
 			if e.Cause() != nil {
 				hasCause, ok := e.Cause().(Errors)
 				if !ok {
-					fmt.Fprintf(s, "%v\n", e.Cause())
+					_, _ = fmt.Fprintf(s, "%v\n", e.Cause())
 				} else {
 					hasCause.Format(s, verb)
 				}
 			}
+		case s.Flag('-'):
+			_, _ = io.WriteString(s, "{")
+			_, _ = fmt.Fprintf(s, `"msg":"%s", "occurTime":"%s", "stack":[`, e.Error(), e.OccurTime())
+			for i, pc := range e.PCS() {
+				if i > 0 {
+					_, _ = io.WriteString(s, ",")
+				}
+				fn := runtime.FuncForPC(pc)
+				if fn == nil {
+					_, _ = fmt.Fprintf(s, `{"fn":"%s", "home":"%s", "file":"%s", "line":%d}`, "unknown", "unknown", "unknown", 0)
+				} else {
+					file, line := fn.FileLine(pc)
+					home, filename := fileName(file)
+					_, _ = fmt.Fprintf(s, `{"fn":"%s", "home":"%s", "file":"%s", "line":%d}`, fn.Name(), home, filename, line)
+				}
+			}
+			_, _ = io.WriteString(s, "]")
+			if e.Cause() != nil {
+				_, _ = io.WriteString(s, ",")
+				hasCause, ok := e.Cause().(Errors)
+				if !ok {
+					_, _ = fmt.Fprintf(s, `"cause":{"msg":"%s"}`, e.Cause().Error())
+				} else {
+					_, _ = io.WriteString(s, `"cause":`)
+					hasCause.Format(s, verb)
+				}
+			}
+			_, _ = io.WriteString(s, "}")
 		default:
-			fmt.Fprintf(s, "%s", e.Error())
+			_, _ = fmt.Fprintf(s, "%s", e.Error())
 		}
 	}
 }

go.mod

@@ -0,0 +1,3 @@
+module github.com/pharosnet/errors
+
+go 1.14