add Is/Equal/Unwrap functions for package gerror

errors/gerror/gerror_error_stack.go

@@ -0,0 +1,42 @@
+// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
+//
+// This Source Code Form is subject to the terms of the MIT License.
+// If a copy of the MIT was not distributed with this file,
+// You can obtain one at https://github.com/gogf/gf.
+
+package gerror
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// Stack returns the stack callers as string.
+// It returns an empty string if the `err` does not support stacks.
+func (err *Error) Stack() string {
+	if err == nil {
+		return ""
+	}
+	var (
+		loop   = err
+		index  = 1
+		buffer = bytes.NewBuffer(nil)
+	)
+	for loop != nil {
+		buffer.WriteString(fmt.Sprintf("%d. %-v\n", index, loop))
+		index++
+		formatSubStack(loop.stack, buffer)
+		if loop.error != nil {
+			if e, ok := loop.error.(*Error); ok {
+				loop = e
+			} else {
+				buffer.WriteString(fmt.Sprintf("%d. %s\n", index, loop.error.Error()))
+				index++
+				break
+			}
+		} else {
+			break
+		}
+	}
+	return buffer.String()
+}