adding cd

src/builtin.rs

@@ -1,5 +1,7 @@
+mod cd;
 mod echo;
 mod printenv;
+mod tail;
 mod which;
 
 use crate::{
@@ -10,8 +12,10 @@ use std::collections::HashMap;
 
 #[derive(Clone, Copy)]
 pub enum Builtin {
+    Changedir,
     Echo,
     Printenv,
+    Tail,
     Which,
 }
 
@@ -19,8 +23,10 @@ impl Builtin {
     fn resolve(&self) -> &dyn Call {
         use Builtin::*;
         match self {
+            Changedir => &cd::Changedir,
             Echo => &echo::Echo,
             Printenv => &printenv::Printenv,
+            Tail => &tail::Tail,
             Which => &which::Which,
         }
     }
@@ -34,5 +40,11 @@ impl Call for Builtin {
 
 pub fn all() -> HashMap<&'static str, Builtin> {
     use Builtin::*;
-    HashMap::from([("echo", Echo), ("printenv", Printenv), ("which", Which)])
+    HashMap::from([
+        ("cd", Changedir),
+        ("echo", Echo),
+        ("printenv", Printenv),
+        ("tail", Tail),
+        ("which", Which),
+    ])
 }

src/builtin/cd.rs

@@ -0,0 +1,25 @@
+use crate::{
+    error::ExecError,
+    run::{Call, Context, Value},
+};
+use std::{env, io::Write, os, process};
+
+pub struct Changedir;
+
+impl Call for Changedir {
+    fn call(&self, ctx: &mut Context, args: &[Value]) -> Result<Value, ExecError> {
+        match args.len() {
+            0 => {
+                todo!()
+            }
+            1 => {
+                let name = args[0].try_as_str()?;
+                env::set_current_dir(name).map_err(|e| ExecError::Misc(e.to_string()))?;
+            }
+            _ => {
+                todo!()
+            }
+        }
+        Ok(Value::None)
+    }
+}

src/builtin/tail.rs

@@ -1,30 +1,18 @@
 use crate::{
-    ext::Command,
-    output,
+    error::ExecError,
+    run::{Call, Context, Value},
 };
-
 use std::{
     fs::File,
-    io::{Seek, SeekFrom, Read, Write},
+    io::{Read, Seek, SeekFrom, Write},
 };
 
-use anyhow::Result;
-
-pub struct Tail { }
-
-impl Command for Tail {
-    fn name() -> String {
-        String::from("tail")
-    }
-
-    fn create() -> Self {
-        Self{ }
-    }
+pub struct Tail;
 
-    fn exec(&mut self, args: Vec<&str>) -> Result<bool> {
-        let mut stdout = output::Writer::stdout()?;
+impl Call for Tail {
+    fn call(&self, ctx: &mut Context, args: &[Value]) -> Result<Value, ExecError> {
         if args.len() > 0 {
-            let fname = args[0];
+            let fname = args[0].try_as_str()?;
             match File::options().read(true).open(fname) {
                 Ok(mut f) => {
                     _ = f.seek(SeekFrom::End(0));
@@ -36,7 +24,7 @@ impl Command for Tail {
                                 if n == 1 {
                                     buf.push(one_byte[0]);
                                     if let Ok(s) = std::str::from_utf8(&buf) {
-                                        stdout.write(s.as_bytes())?;
+                                        _ = ctx.stdout.write(s.as_bytes());
                                         buf.clear();
                                     }
                                 }
@@ -46,13 +34,10 @@ impl Command for Tail {
                     }
                 }
                 Err(e) => {
-                    println!("failed to open file: {}", e);
-                    return Err(e.into());
+                    write!(ctx.stderr, "failed to open file: {}", e);
                 }
             }
-        } else {
-            println!("need a file name");
-            return Ok(false);
         }
+        Ok(Value::None)
     }
 }

src/error.rs

@@ -82,6 +82,9 @@ pub enum ExecError {
 
     #[error("value type error: {0}")]
     ValueTypeError(String),
+
+    #[error("error")]
+    Misc(String),
 }
 
 impl ExecError {

src/ext.rs

@@ -1,8 +1,6 @@
 mod command;
-mod tail;
 
 pub use command::Command;
-pub use tail::Tail;
 
 /*
 Posix Shell builtins:

src/lex.rs

@@ -78,12 +78,26 @@ impl Token {
     fn same(&self, other: &Self) -> bool {
         use Token::*;
 
+        println!(
+            "check same self: {self:?} other: {other:?}",
+            self = self.text(),
+            other = other.text()
+        );
+
         match (self, other) {
             (Word(a), Word(b)) => a.text() == b.text(),
             (Glob(a), Glob(b)) => a.text() == b.text(),
             _ => false,
         }
     }
+
+    fn text(&self) -> String {
+        use Token::*;
+
+        match self {
+            Word(lexeme) | Glob(lexeme) => lexeme.text(),
+        }
+    }
 }
 
 /// Tokenizer splits some input [Glyphs] into [Token] values
@@ -107,10 +121,10 @@ impl<'text> Tokenizer<'text> {
         match next.glyph {
             _ if next.is_word() => Some(self.lex_bare_string(vec![next])),
             _ if next.is_glob() => Some(self.lex_glob(vec![next])),
-            '\\' => match self.source.pop() {
-                Ok(escaped) => Some(self.lex_bare_string(vec![escaped])),
-                Err(e) => Some(Err(e)),
-            },
+            // '\\' => match self.source.pop() {
+            //     Ok(escaped) => Some(self.lex_bare_string(vec![escaped])),
+            //     Err(e) => Some(Err(e)),
+            // },
             '@' => Some(self.lex_var(vec![next])),
             '\'' => Some(self.lex_raw_string(vec![next])),
             '"' => Some(self.lex_interp_string(vec![next])),
@@ -127,10 +141,10 @@ impl<'text> Tokenizer<'text> {
                     progress.push(self.source.pop()?);
                     return self.lex_glob(progress);
                 }
-                '\\' => {
-                    self.source.pop()?;
-                    progress.push(self.source.pop()?);
-                }
+                // '\\' => {
+                //     self.source.pop()?;
+                //     progress.push(self.source.pop()?);
+                // }
                 _ => return Err(LexError::UnexpectedCharacter(self.source.pop()?)),
             }
         }
@@ -147,10 +161,10 @@ impl<'text> Tokenizer<'text> {
             match next.glyph {
                 _ if next.glyph.is_whitespace() => break,
                 _ if next.is_glob() => progress.push(self.source.pop()?),
-                '\\' => {
-                    self.source.pop()?;
-                    progress.push(self.source.pop()?);
-                }
+                // '\\' => {
+                //     self.source.pop()?;
+                //     progress.push(self.source.pop()?);
+                // }
                 _ => return Err(LexError::UnexpectedCharacter(self.source.pop()?)),
             }
         }
@@ -271,6 +285,7 @@ mod tests {
             assert_eq!(expected.len(), lexed.len());
 
             for pair in zip(expected, lexed) {
+                println!("pair: {pair:?}");
                 assert!(pair.0.same(&pair.1));
             }
 
@@ -295,13 +310,6 @@ mod tests {
     }
 
     reject! {
-        // A slash on its own makes no sense
-        lonely_slash: r"\";
-
-        // A slash is an escape character, so starting the escape sequence and then ending the
-        // input makes no sense
-        trailing_slash: r"one two three \";
-
         // Vars aren't done yet
         var: "@name";
 
@@ -332,5 +340,7 @@ mod tests {
         glob_4 "*x" [ glob("*x") ]
         glob_5 "*.py" [ glob("*.py") ]
         mixed_1 "ls *.py" [ word("ls") glob("*.py") ]
+        abs "cd c:\\one\\two" [ word("cd") word("c:\\one\\two")]
+        home "cd ~\\stuff" [ word("cd") word("~\\stuff") ]
     }
 }

src/run.rs

@@ -1,4 +1,4 @@
-use crate::{builtin, error::ExecError, input, output};
+use crate::{builtin, error::ExecError, output};
 use std::{collections::HashMap, process};
 
 /// Eval represents anything that can be evaluated at runtime.

src/topo.rs

@@ -65,7 +65,10 @@ pub struct Glyph {
 impl Glyph {
     /// checks to see whether or not the character for this glyph is a word character
     pub fn is_word(&self) -> bool {
-        self.glyph.is_alphanumeric() || self.glyph == '.'
+        match self.glyph {
+            '-' | '/' | '\\' | '.' | ':' | '~' => true,
+            _ => self.glyph.is_alphanumeric(),
+        }
     }
 
     /// checks to see whether or not the character for this glyph is a glob character