restructure project

internal/object/object.go

@@ -0,0 +1,60 @@
+package object
+
+import "fmt"
+
+// Type represents the type of an object
+type ObjectType string
+
+const (
+	INTEGER_OBJ           = "int"
+	BOOLEAN_OBJ           = "bool"
+	NULL_OBJ              = "null"
+	RETURN_VALUE_OBJ      = "return"
+	ERROR_OBJ             = "error"
+	FUNCTION_OBJ          = "fn"
+	STRING_OBJ            = "str"
+	BUILTIN_OBJ           = "builtin"
+	ARRAY_OBJ             = "array"
+	HASH_OBJ              = "hash"
+	COMPILED_FUNCTION_OBJ = "COMPILED_FUNCTION"
+	CLOSURE_OBJ           = "closure"
+	MODULE_OBJ            = "module"
+)
+
+// Comparable is the interface for comparing two Object and their underlying
+// values. It is the responsibility of the caller (left) to check for types.
+// Returns `true` iif the types and values are identical, `false` otherwise.
+type Comparable interface {
+	Compare(other Object) int
+}
+
+// Sizeable is the interface for returning the size of an Object.
+// Object(s) that have a valid size must implement  this interface and the
+// Len() method.
+type Sizeable interface {
+	Len() int
+}
+
+// Immutable is the interface for all immutable objects which must implement
+// the Clone() method used by binding names to values.
+type Immutable interface {
+	Clone() Object
+}
+
+// Object represents a value and implementations are expected to implement
+// `Type()` and `Inspect()` functions
+type Object interface {
+	fmt.Stringer
+	Type() ObjectType
+	Bool() bool
+	Inspect() string
+}
+
+// Hashable is the interface for all hashable objects which must implement
+// the HashKey() method which returns a HashKey result.
+type Hashable interface {
+	HashKey() HashKey
+}
+
+// BuiltinFunction represents the builtin function type
+type BuiltinFunction func(args ...Object) Object