Implement parser

src/elements/command/simple.rs

@@ -103,18 +103,17 @@ impl SimpleCommand {
     }
 
     fn eat_word(feeder: &mut Feeder, ans: &mut SimpleCommand, core: &mut ShellCore) -> bool {
-        let word_len = feeder.scanner_word(core);
-        if word_len == 0 {
-            return false;
-        }
-
-        let word = feeder.consume(word_len);
-        if ans.words.len() == 0 && reserved(&word) {
+        let w = match Word::parse(feeder, core) {
+            Some(w) => w,
+            _       => return false,
+        };
+
+        if ans.words.len() == 0 && reserved(&w.text) {
             return false;
         }
- 
-        ans.text += &word.clone();
-        ans.words.push(Word{ text: word });
+
+        ans.text += &w.text;
+        ans.words.push(w);
         true
     }
 

src/elements/word.rs

@@ -1,6 +1,8 @@
 //SPDX-FileCopyrightText: 2023 Ryuichi Ueda ryuichiueda@gmail.com
 //SPDX-License-Identifier: BSD-3-Clause
 
+use crate::{ShellCore, Feeder};
+
 #[derive(Debug)]
 pub struct Word {
     pub text: String,
@@ -10,4 +12,23 @@ impl Word {
     pub fn get_args(&mut self) -> Vec<String> {
         vec![self.text.clone()]
     }
+
+    fn new() -> Word {
+        Word {
+            text: String::new(),
+        }
+    }
+
+    pub fn parse(feeder: &mut Feeder, core: &mut ShellCore) -> Option<Word> {
+        let mut ans = Word::new();
+        let arg_len = feeder.scanner_word(core);
+
+        if arg_len > 0 {
+            ans.text = feeder.consume(arg_len);
+            Some(ans)
+        }else{
+            None
+        }
+     }
 }
+