Initial project import

tools/v/vlib/toml/input/input.v

@@ -0,0 +1,35 @@
+// Copyright (c) 2021 Lars Pontoppidan. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module input
+
+import os
+
+// Config is used to configure input to the toml module.
+// Only one of the fields `text` and `file_path` is allowed to be set at time of configuration.
+pub struct Config {
+pub:
+	text      string // TOML text
+	file_path string // '/path/to/file.toml'
+}
+
+// read_input returns either Config.text or the read file contents of Config.file_path
+// depending on which one is not empty.
+pub fn (c Config) read_input() !string {
+	if c.file_path != '' && c.text != '' {
+		return error(@MOD + '.' + @FN +
+			' ${typeof(c).name} should contain only one of the fields `file_path` OR `text` filled out')
+	}
+	if c.file_path == '' && c.text == '' {
+		// TODO: passing both empty is used *a lot* by `./v vlib/toml/tests/toml_lang_test.v`; investigate why.
+		return ''
+	}
+	if c.text != '' {
+		return c.text
+	}
+	text := os.read_file(c.file_path) or {
+		return error(@MOD + '.' + @STRUCT + '.' + @FN +
+			' Could not read "${c.file_path}": "${err.msg()}"')
+	}
+	return text
+}