bash-like syntax

bash_info.md

@@ -0,0 +1,20 @@
+# invalid
+```bash
+$a="b"
+a = "b"
+a= "b"
+a ="b"
+```
+
+# valid
+```bash
+a="b"
+a=b
+```
+
+# examples
+```bash
+a="b c d"
+echo $a
+# output: b c d
+```

src/command.rs

@@ -1,11 +1,52 @@
 use std::{
+    collections::HashMap,
     fs,
     path::Path,
     process,
 };
 
-pub type Param<'a, 'b> = &'b [&'a str];
-trait Run = Fn(Param);
+use crate::SPECIAL_CHAR;
+
+type InnerEnv = HashMap<String, String>;
+pub struct Env {
+    inner: InnerEnv,
+}
+
+impl Env {
+    pub fn new() -> Self {
+        Self {
+            inner: HashMap::new(),
+        }
+    }
+    pub fn as_env(&self) -> &InnerEnv {
+        &self.inner
+    }
+    pub fn get(&self, var: &str) -> Option<&String> {
+        self.inner.get(var)
+    }
+    pub fn set(&mut self, var: &str, val: &str) {
+        self.inner.insert(var.to_owned(), val.to_owned());
+    }
+    pub fn unset(&mut self, var: &str) {
+        self.inner.remove(var);
+    }
+    pub fn apply_args_substitution(&self, args: Args) -> Vec<String> {
+        args.iter().fold(Vec::new(), |mut vec, arg| {
+            if arg.starts_with(SPECIAL_CHAR) {
+                // we take a slice to get rid of the '$'
+                if let Some(sub) = self.get(&arg[1..]) {
+                    vec.push(sub.to_owned());
+                    return vec;
+                }
+            }
+            vec.push(arg.to_string());
+            vec
+        })
+    }
+}
+
+pub type Args<'a, 'b> = &'b [String];
+trait Run = Fn(Args, &mut Env);
 type Cmd = Box<dyn Run>;
 
 pub struct Command {
@@ -26,129 +67,108 @@ impl Command {
         }
     }
 
-    pub fn call(&self, words: Param) {
+    pub fn call(&self, words: Args, env: &mut Env) {
         let x = &self.cmd;
-        x(words)
+        x(words, env)
     }
 
-    pub fn choose<'a>(text: &str, choices: &'a Vec<Self>) -> Option<&'a Self> {
-        // TODO there seems to be duplicates in here?
-
+    pub fn choose<'a>(text: &str, choices: &'a [Self]) -> Option<&'a Self> {
         // See what command the user is trying to call
-        // iter thru all the commands
-        let mut ranked = choices.iter().fold(Vec::new(), |mut v, cmd| {
-            // count how many chars match from the command to the word
-            let matches = text
-                .chars()
-                .zip(cmd.name.chars())
-                .fold(0, |mut f, (word, cmd)| {
-                    if word == cmd {
-                        f += 1;
-                    }
-                    f
-                });
-            v.push((cmd, matches));
-            v
-        });
+        let matches = choices
+            .iter()
+            .filter(|cmd| cmd.name.starts_with(text))
+            .collect::<Vec<&Command>>();
 
-        // sort by most matches
-        ranked.sort_by(|a, b| b.1.cmp(&a.1));
+        // If there are more than two commands that match the filter we don't know which one they want
+        if matches.len() > 1 {
+            // ❗ Here till the return is all just debug output
+            println!("Ambiguous command '{text}'. Could be any of: ");
+            // The most amount of choices that will be presented as collisions
+            let max_display = 5;
+            let max_display = if max_display < matches.len() { max_display } else { matches.len() };
 
-        // Don't select commands just because they are first. The command also has to have a
-        // confidence of at least 1
-        if let Some(first) = ranked.first() {
-            if first.1 < 1 {
-                return None;
+            matches[..max_display].iter().for_each(|matching| {
+                println!("\t- {}", matching.name);
+            });
+
+            if matches.len() > max_display {
+                println!(
+                    "\t+ Omitting {} other entries...",
+                    matches.len() - max_display
+                );
             }
+            return None;
         }
 
-        // TODO test when 1 100% match exists
-
-        if ranked.len() > 1 {
-            // If the top two command choices are ranked the same, we don't know which to choose!
-            let top = ranked[0];
-            let second = ranked[1];
-            if top.1 == second.1 {
-                println!("Ambigous command '{text}'. Could be any of: ");
-                let iter: Vec<&(&Command, usize)> = ranked
-                    .iter()
-                    // We only care about 100% matches
-                    .filter(|f| f.1 >= text.len())
-                    .collect();
-
-                let max_display = if 5 < iter.len() {5} else {iter.len()};
-
-                iter[..max_display].iter().for_each(|matching| {
-                        println!("\t- {}", matching.0.name);
-                    });
-
-                if iter.len() > max_display {
-                    println!("\t+ Omitting {} other entries...", iter.len() - max_display);
-                }
-
-                return None;
-            }
-        }
-
-        if let Some((cmd, _)) = ranked.first() {
+        if let Some(cmd) = matches.first() {
             return Some(cmd);
         }
         None
     }
 
-    pub fn all_commands() -> Vec<Self> {
-        let path = Path::new("/bin");
-        let res = fs::read_dir(path).expect("Failed to read /bin");
-
-        // load all the programs from /bin
-        let bin = res.fold(Vec::new(), |mut v, contents| {
-            if let Ok(cmd) = contents {
-                if let Ok(t) = cmd.file_type() {
-                    if t.is_file() {
-                        // v.push(cmd.path());
-                        let cmd = Command::init(
-                            cmd.file_name().into_string().unwrap(),
-                            vec![],
-                            Box::new(move |args| {
-                                let name = cmd.path().to_str().unwrap().to_owned();
-                                let out = process::Command::new(name)
-                                    .args(args)
-                                    .output()
-                                    .expect("Failed to call external program");
-                                // FIXME not printing to out
-                                //
-                                let output = String::from_utf8_lossy(&out.stdout);
-                                let errout = String::from_utf8_lossy(&out.stderr);
-                                // TODO load into env
-                                let status = out.status.code();
-                                println!("{:?} output: {output}", status);
-                                println!("{:?} err: {errout}", status);
-                            }),
-                        );
-                        v.push(cmd);
-                    }
+    fn load_from(path: &str) -> Vec<Command> {
+        let path = Path::new(path);
+        if let Ok(res) = fs::read_dir(path) {
+            // load all the programs from /bin
+            let bin = res.fold(Vec::new(), |mut v, contents| {
+                if let Ok(cmd) = contents {
+                    if let Ok(t) = cmd.file_type() {
+                        if t.is_file() {
+                            // v.push(cmd.path());
+                            let cmd = Command::init(
+                                cmd.file_name().into_string().unwrap(),
+                                vec![],
+                                Box::new(move |args: Args, env: &mut Env| {
+                                    let name = cmd.path().to_str().unwrap().to_owned();
+                                    let out = process::Command::new(name)
+                                        .args(&args[1..])
+                                        .envs(env.as_env())
+                                        .output()
+                                        .expect("Failed to call external program");
+                                    // TODO load into env
+                                    if let Some(status) = out.status.code() {
+                                        env.set("?", &status.to_string());
+                                    }
+                                    if !out.stdout.is_empty() {
+                                        let output = String::from_utf8_lossy(&out.stdout);
+                                        println!("{output}");
+                                    }
+                                    if !out.stderr.is_empty() {
+                                        let errout = String::from_utf8_lossy(&out.stderr);
+                                        println!("{errout}");
+                                    }
+                                }),
+                            );
+                            v.push(cmd);
+                        }
+                    };
                 };
-            };
-            v
-        });
+                v
+            });
+            return bin;
+        }
+        // invalid path was passed, just return an empty vec
+        Vec::new()
+    }
 
+    pub fn all_commands(env: &Env) -> Vec<Self> {
         // load custom programs
         let mut commands = vec![
             Command::init(
                 "exit",
                 vec![],
-                Box::new(|_| {
+                Box::new(|_, _| {
                     std::process::exit(0);
                 }),
             ),
             Command::init(
-                "custom_echo",
+                "echo",
                 vec![],
-                Box::new(|args| {
+                Box::new(|args, _| {
                     let msg = &args[1..]
                         .iter()
                         .map(|s| s.to_owned())
-                        .intersperse(" ")
+                        .intersperse(" ".to_string())
                         .collect::<String>();
                     println!("{msg}");
                 }),
@@ -159,7 +179,7 @@ impl Command {
                     Command::init(
                         "number",
                         vec![],
-                        Box::new(|_| {
+                        Box::new(|_, _| {
                             // how do you know it's not random?
                             println!("8");
                         }),
@@ -167,20 +187,26 @@ impl Command {
                     Command::init(
                         "string",
                         vec![],
-                        Box::new(|_| {
+                        Box::new(|_, _| {
                             // how do you know it's not random?
                             println!("hello world");
                         }),
                     ),
                 ],
-                Box::new(|args| {
+                Box::new(|args, _| {
                     println!("random's debug: {:?}", args);
                 }),
             ),
         ];
 
+        // $PATH
+        if let Some(path_var) = env.get("PATH") {
+            let paths = path_var.split(';').collect::<Vec<&str>>();
+            for path in paths {
+                commands.extend(Command::load_from(path));
+            }
+        }
         // combine with a move
-        commands.extend(bin);
         commands
     }
 }

src/main.rs

@@ -1,24 +1,30 @@
 #![feature(iter_intersperse)]
 #![feature(trait_alias)]
 use std::io::{BufRead, Write};
-use command::{Command, Param};
+use command::{Command, Env, Args};
 
 mod command;
 
+pub static SPECIAL_CHAR: char = '$';
+
 fn main() {
     let stdin = std::io::stdin();
     let mut in_lock = stdin.lock();
 
     let stdout = std::io::stdout();
     let mut out_lock = stdout.lock();
+    
+    let mut env= Env::new();
+    env.set("HOME", "/a/fake/dir");
 
-    let commands = &Command::all_commands();
+    let commands = &Command::all_commands(&env);
     println!("Loaded {} commands", commands.len());
 
     loop {
         let mut buf = String::new();
 
-        let ps1 = "> ".as_bytes();
+        let default_ps1 = "> ".to_string();
+        let ps1 = env.get("PS1").unwrap_or(&default_ps1).as_bytes();
         out_lock.write(ps1).unwrap();
         out_lock.flush().unwrap();
 
@@ -26,38 +32,74 @@ fn main() {
             .read_line(&mut buf)
             .expect("Failed to read in to buffer.");
 
-        let mut args: Param = &buf.trim().split(' ').collect::<Vec<&str>>();
+        // TODO split at ' ' but don't split when it's surrounded by quotes '"'
+        let args= &buf.trim().split(' ').map(|f| f.to_owned()).collect::<Vec<String>>();
+        let args = env.apply_args_substitution(args);
+        let mut args: Args = &args;
+
+        // let mut args: Args = &buf.trim().split(' ').collect::<Vec<&str>>();
         let mut options = commands;
 
         loop {
-
-            match args.get(0) {
+            match args.first() {
                 Some(cmd_arg) => {
                     // Try to find a subcommand to run
                     match Command::choose(cmd_arg, options) {
                         Some(choice) => {
+                            // No sub commands left to choose from, just pass the input
                             if choice.sub_commands.is_empty() {
-                                // No sub commands left to choose from, just pass the input
-                                choice.call(&args);
+                                choice.call(&args, &mut env);
                                 break;
-                            } else {
-                                args = &args[1..];
-                                options = &choice.sub_commands;
+                            } 
 
-                                // a sort of last chance before running into hella edgecases
-                                if args.is_empty() {
-                                    choice.call(args);
-                                    break;
-                                }
+                            args = &args[1..];
+                            options = &choice.sub_commands;
+
+                            // a sort of last chance before running into hella edgecases
+                            if args.is_empty()
+                            || Command::choose(&args[0], options).is_none() // yes, this means that we search for a choice twice if it misses, but the search takes all of 0ms, so it's fine.
+                            {
+                                choice.call(&args, &mut env);
+                                break;
                             }
                         }
                         // When no good choice presents it's self
-                        None => break,
+                        None => {
+                            // perhaps they are trying to use builtins?
+                            parse_lang(&args, &mut env);
+                            break;
+                        },
                     }
                 }
-                None => todo!("Couldn't get index 0 of the args"),
+                None => unimplemented!("Couldn't get index 0 of the args"),
             }
         }
     }
 }
 
+fn parse_lang(tokens: Args, env: &mut Env) {
+    if let Some(first) =  tokens.first() {
+        if let Some((var, val)) = first.split_once('=') {
+            let var = var.replace(SPECIAL_CHAR, "");
+
+            // Make it so that strings don't get spliced up
+            let val = if val.starts_with('"') {
+                let mut buf = String::new();
+                buf += &val;
+                for i in &tokens[1..] {
+                    buf += " ";
+                    buf += i;
+                    if i.ends_with('"') {
+                        break;
+                    }
+                }
+                buf.replace('"', "")
+            } else {
+                val.to_owned()
+            };
+            env.set(&var, &val);
+        } else {
+            println!("first token is not a command but also doesn't include '='");
+        }
+    }
+}