tools,vls: add v test-parser examples/hello_world.v (#7145)

vlib/os/args.v

@@ -0,0 +1,51 @@
+// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module os
+
+// args_after returns all os.args, located *after* a specified `cut_word`.
+// When `cut_word` is NOT found, os.args is returned unmodified.
+pub fn args_after(cut_word string) []string {
+	if args.len == 0 {
+		return []string{}
+	}
+	mut cargs := []string{}
+	if cut_word !in args {
+		cargs = args
+	} else {
+		mut found := false
+		cargs << args[0]
+		for a in args[1..] {
+			if a == cut_word {
+				found = true
+				continue
+			}
+			if !found {
+				continue
+			}
+			cargs << a
+		}
+	}
+	return cargs
+}
+
+// args_after returns all os.args, located *before* a specified `cut_word`.
+// When `cut_word` is NOT found, os.args is returned unmodified.
+pub fn args_before(cut_word string) []string {
+	if args.len == 0 {
+		return []string{}
+	}
+	mut cargs := []string{}
+	if cut_word !in args {
+		cargs = args
+	} else {
+		cargs << args[0]
+		for a in args[1..] {
+			if a == cut_word {
+				break
+			}
+			cargs << a
+		}
+	}
+	return cargs
+}