umx_compiler

commit 6c59b6321eacbed957c968a8509a8ada02b6db2c
parent 64106aab37d2ec0151ef87b83cbaa1dd2481d178
Author: bsandro <email@bsandro.tech>
Date:   Wed, 29 Jun 2022 00:23:57 +0300

array builtin functions: first, last, push, pop, rpush, rpop

Diffstat:
M
eval/builtins.go
 | 
97
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 97 insertions(+), 0 deletions(-)
diff --git a/eval/builtins.go b/eval/builtins.go
@@ -18,4 +18,101 @@ var builtins = map[string]*object.Builtin{
 			}
 		},
 	},
+	"first": &object.Builtin{
+		Fn: func(args ...object.Object) object.Object {
+			if len(args) != 1 {
+				return newError("invalid number of arguments")
+			}
+			if args[0].Type() != object.ARRAY_OBJ {
+				return newError("argument has to be an array")
+			}
+			arr := args[0].(*object.Array)
+			if len(arr.Elements) > 0 {
+				return arr.Elements[0]
+			}
+			return NULL
+		},
+	},
+	"last": &object.Builtin{
+		Fn: func(args ...object.Object) object.Object {
+			if len(args) != 1 {
+				return newError("invalid number of arguments")
+			}
+			if args[0].Type() != object.ARRAY_OBJ {
+				return newError("argument has to be an array")
+			}
+			arr := args[0].(*object.Array)
+			arrLen := len(arr.Elements)
+			if arrLen > 0 {
+				return arr.Elements[arrLen-1]
+			}
+			return NULL
+		},
+	},
+	"push": &object.Builtin{
+		Fn: func(args ...object.Object) object.Object {
+			if len(args) != 2 {
+				return newError("invalid number of arguments")
+			}
+			if args[0].Type() != object.ARRAY_OBJ {
+				return newError("argument has to be an array")
+			}
+			arr := args[0].(*object.Array)
+			newElements := append(arr.Elements, args[1])
+			return &object.Array{Elements: newElements}
+		},
+	},
+	"pop": &object.Builtin{
+		Fn: func(args ...object.Object) object.Object {
+			if len(args) != 1 {
+				return newError("invalid number of arguments")
+			}
+			if args[0].Type() != object.ARRAY_OBJ {
+				return newError("argument has to be an array")
+			}
+			arr := args[0].(*object.Array)
+			arrLen := len(arr.Elements)
+			if arrLen > 1 {
+				newElements := make([]object.Object, arrLen-1, arrLen-1)
+				copy(newElements, arr.Elements[:arrLen-1])
+				return &object.Array{Elements: newElements}
+			} else {
+				var emptyArr []object.Object
+				return &object.Array{Elements: emptyArr}
+			}
+		},
+	},
+	"rpush": &object.Builtin{
+		Fn: func(args ...object.Object) object.Object {
+			if len(args) != 2 {
+				return newError("invalid number of arguments")
+			}
+			if args[0].Type() != object.ARRAY_OBJ {
+				return newError("argument has to be an array")
+			}
+			arr := args[0].(*object.Array)
+			newElements := append([]object.Object{args[1]}, arr.Elements...)
+			return &object.Array{Elements: newElements}
+		},
+	},
+	"rpop": &object.Builtin{
+		Fn: func(args ...object.Object) object.Object {
+			if len(args) != 1 {
+				return newError("invalid number of arguments")
+			}
+			if args[0].Type() != object.ARRAY_OBJ {
+				return newError("argument has to be an array")
+			}
+			arr := args[0].(*object.Array)
+			arrLen := len(arr.Elements)
+			if arrLen > 1 {
+				newElements := make([]object.Object, arrLen-1, arrLen-1)
+				copy(newElements, arr.Elements[1:arrLen])
+				return &object.Array{Elements: newElements}
+			} else {
+				var emptyArr []object.Object
+				return &object.Array{Elements: emptyArr}
+			}
+		},
+	},
 }