New domain errors based on the ICU-019 RFC (#760)

internal/errors/code.go

@@ -0,0 +1,35 @@
+package errors
+
+// Code specifies a code for the error.
+type Code uint32
+
+// String will return the Code's Info.Message
+func (c Code) String() string {
+	return c.Info().Message
+}
+
+// Info will look up the Code's Info.  If the Info is not found, it will return
+// Info for an Unknown Code.
+func (c Code) Info() Info {
+	if info, ok := errorCodeInfo[c]; ok {
+		return info
+	}
+	return errorCodeInfo[Unknown]
+}
+
+const (
+	Unknown Code = 0 // Unknown will be equal to a zero value for Codes
+
+	// General function errors are reserved Codes 100-999
+	InvalidParameter Code = 100 // InvalidParameter represents and invalid parameter for an operation.
+
+	// DB errors are resevered Codes from 1000-1999
+	CheckConstraint      Code = 1000 // CheckConstraint represents a check constraint error
+	NotNull              Code = 1001 // NotNull represents a value must not be null error
+	NotUnique            Code = 1002 // NotUnique represents a value must be unique error
+	NotSpecificIntegrity Code = 1003 // NotSpecificIntegrity represents an integrity error that has no specificy domain error code
+	MissingTable         Code = 1004 // Missing table represents an undefined table error
+	RecordNotFound       Code = 1100 // RecordNotFound represents that a record/row was not found matching the criteria
+	MultipleRecords      Code = 1101 // MultipleRecords represents that multiple records/rows were found matching the criteria
+
+)