builtin file operations

object/builtin_read.go

@@ -0,0 +1,26 @@
+package object
+
+import (
+	"os"
+)
+
+// Read ...
+func Read(args ...Object) Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	arg, ok := args[0].(*String)
+	if !ok {
+		return newError("argument to `read` expected to be `str` got=%T", args[0].Type())
+	}
+
+	filename := arg.Value
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		return newError("error reading file: %s", err)
+	}
+
+	return &String{Value: string(data)}
+}

object/builtin_write.go

@@ -0,0 +1,32 @@
+package object
+
+import (
+	"os"
+)
+
+// Write ...
+func Write(args ...Object) Object {
+	if len(args) != 2 {
+		return newError("wrong number of arguments. got=%d, want=2",
+			len(args))
+	}
+
+	arg, ok := args[0].(*String)
+	if !ok {
+		return newError("argument #1 to `write` expected to be `str` got=%T", args[0].Type())
+	}
+	filename := arg.Value
+
+	arg, ok = args[1].(*String)
+	if !ok {
+		return newError("argument #2 to `write` expected to be `str` got=%T", args[1].Type())
+	}
+	data := []byte(arg.Value)
+
+	err := os.WriteFile(filename, data, 0755)
+	if err != nil {
+		return newError("error writing file: %s", err)
+	}
+
+	return &Null{}
+}

object/builtins.go

@@ -27,6 +27,8 @@ var Builtins = map[string]*Builtin{
 	"join":   {Name: "join", Fn: Join},
 	"split":  {Name: "split", Fn: Split},
 	"find":   {Name: "find", Fn: Find},
+	"read":   {Name: "read", Fn: Read},
+	"write":  {Name: "write", Fn: Write},
 }
 
 // BuiltinsIndex ...