lots of new things! almost a language

Cargo.toml

@@ -9,3 +9,4 @@ edition = "2021"
 ariadne = { git = "https://github.com/zesterer/ariadne" }
 chumsky = { git = "https://github.com/zesterer/chumsky", features = ["label"] }
 imbl = "3.0.0"
+tailcall = "1.0.1"

src/main.rs

@@ -26,7 +26,6 @@
 // * [ ] perf testing
 
 use chumsky::{input::Stream, prelude::*};
-use std::rc::Rc;
 
 mod spans;
 
@@ -34,7 +33,6 @@ mod lexer;
 use crate::lexer::*;
 
 mod value;
-use crate::value::*;
 
 mod parser;
 use crate::parser::*;
@@ -43,7 +41,10 @@ mod vm;
 use crate::vm::*;
 
 pub fn main() {
-    let src = "when { 0 -> :false; true -> :true}";
+    let src = "
+#{:a 1, :b 2}
+
+    ";
     let (tokens, lex_errs) = lexer().parse(src).into_output_errors();
     if lex_errs.len() > 0 {
         println!("{:?}", lex_errs);
@@ -51,15 +52,15 @@ pub fn main() {
     }
     let tokens = tokens.unwrap();
     let to_parse = tokens.clone();
-    for (token, _) in tokens {
-        println!("{}", token)
-    }
+    // for (token, _) in tokens {
+    //     println!("{}", token)
+    // }
     let (ast, _) = parser()
         .parse(Stream::from_iter(to_parse).map((0..src.len()).into(), |(t, s)| (t, s)))
         .unwrap();
-    println!("{}", ast);
+    // println!("{}", ast);
 
-    let mut ctx = vec![("foo", Value::Number(42.0))];
+    let mut ctx = vec![];
 
     let result = eval(&ast, &mut ctx).unwrap();
 

src/parser.rs

@@ -32,6 +32,18 @@ impl<'src> fmt::Display for MatchClause<'src> {
     }
 }
 
+#[derive(Clone, Debug, PartialEq)]
+pub struct Pair<'src> {
+    pub key: &'src str,
+    pub value: Spanned<Ast<'src>>,
+}
+
+impl<'src> fmt::Display for Pair<'src> {
+    fn fmt(self: &Pair<'src>, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "pair: {}: {}", self.key, self.value.0)
+    }
+}
+
 #[derive(Clone, Debug, PartialEq)]
 pub enum Ast<'src> {
     Error,
@@ -47,20 +59,19 @@ pub enum Ast<'src> {
     Tuple(Vec<Spanned<Self>>),
     Arguments(Vec<Spanned<Self>>),
     List(Vec<Spanned<Self>>),
-    Pair(&'src str, Box<Spanned<Self>>),
-    Dict(Vec<Spanned<Self>>),
+    Dict(Vec<Pair<'src>>),
     Let(Box<Spanned<Pattern<'src>>>, Box<Spanned<Self>>),
     Box(&'src str, Box<Spanned<Self>>),
     Synthetic(Box<Spanned<Self>>, Box<Spanned<Self>>, Vec<Spanned<Self>>),
     When(Vec<Spanned<WhenClause<'src>>>),
-    Match(Box<Spanned<Self>>, Vec<Spanned<MatchClause<'src>>>),
-    Fn(&'src str, Vec<Spanned<MatchClause<'src>>>),
+    Match(Box<Spanned<Self>>, Vec<MatchClause<'src>>),
+    Fn(&'src str, Vec<MatchClause<'src>>),
     FnDeclaration(&'src str),
     Panic(Box<Spanned<Self>>),
     Do(Vec<Spanned<Self>>),
     Repeat(Box<Spanned<Self>>, Box<Spanned<Self>>),
-    Loop(Box<Spanned<Self>>, Vec<Spanned<Self>>),
-    Recur(Vec<Spanned<Self>>),
+    // Loop(Box<Spanned<Self>>, Vec<Spanned<Self>>),
+    // Recur(Vec<Spanned<Self>>),
 }
 
 impl<'src> fmt::Display for Ast<'src> {
@@ -89,13 +100,12 @@ impl<'src> fmt::Display for Ast<'src> {
             Ast::Let(pattern, expression) => {
                 write!(f, "Let: {} = {}", pattern.0, expression.0)
             }
-            Ast::Pair(kw, expr) => write!(f, "{} {}", kw, expr.0),
             Ast::Dict(entries) => write!(
                 f,
                 "#{{{}}}",
                 entries
                     .iter()
-                    .map(|(pair, _)| pair.to_string())
+                    .map(|pair| pair.to_string())
                     .collect::<Vec<_>>()
                     .join(", ")
             ),
@@ -134,11 +144,54 @@ impl<'src> fmt::Display for Ast<'src> {
                     .collect::<Vec<_>>()
                     .join("\n")
             ),
-            _ => unimplemented!(),
+            Ast::Placeholder => todo!(),
+            Ast::Box(_name, _rhs) => todo!(),
+            Ast::Match(value, clauses) => {
+                write!(
+                    f,
+                    "match: {} with {}",
+                    &value.0.to_string(),
+                    clauses
+                        .iter()
+                        .map(|clause| clause.to_string())
+                        .collect::<Vec<_>>()
+                        .join("\n")
+                )
+            }
+            Ast::Fn(name, clauses) => {
+                write!(
+                    f,
+                    "fn: {}\n{}",
+                    name,
+                    clauses
+                        .iter()
+                        .map(|clause| clause.to_string())
+                        .collect::<Vec<_>>()
+                        .join("\n")
+                )
+            }
+            Ast::FnDeclaration(_name) => todo!(),
+            Ast::Panic(_expr) => todo!(),
+            Ast::Do(_exprs) => todo!(),
+            Ast::Repeat(_times, _body) => todo!(),
+            // Ast::Loop(init, body) => todo!(),
+            // Ast::Recur(args) => todo!(),
         }
     }
 }
 
+#[derive(Clone, Debug, PartialEq)]
+pub struct PairPattern<'src> {
+    pub key: &'src str,
+    pub patt: Spanned<Pattern<'src>>,
+}
+
+impl<'src> fmt::Display for PairPattern<'src> {
+    fn fmt(self: &PairPattern<'src>, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "pair pattern: {}: {}", self.key, self.patt.0)
+    }
+}
+
 #[derive(Clone, Debug, PartialEq)]
 pub enum Pattern<'src> {
     Nil,
@@ -153,8 +206,7 @@ pub enum Pattern<'src> {
     List(Vec<Spanned<Self>>),
     // is this the right representation for Dicts?
     // Could/should this also be a Vec?
-    Pair(&'src str, Box<Spanned<Self>>),
-    Dict(Vec<Spanned<Self>>),
+    Dict(Vec<Spanned<PairPattern<'src>>>),
 }
 
 impl<'src> fmt::Display for Pattern<'src> {
@@ -184,7 +236,6 @@ impl<'src> fmt::Display for Pattern<'src> {
                     .collect::<Vec<_>>()
                     .join(", ")
             ),
-            Pattern::Pair(kw, expr) => write!(f, "{} {}", kw, expr.0),
             Pattern::Dict(entries) => write!(
                 f,
                 "#{{{}}}",
@@ -260,11 +311,14 @@ where
 
     let pair_pattern = select! {Token::Keyword(k) => k}
         .then(pattern.clone())
-        .map_with(|(kw, patt), e| (Pattern::Pair(kw, Box::new(patt)), e.span()));
+        .map_with(|(key, patt), e| (PairPattern { key, patt }, e.span()));
 
     let shorthand_pattern = select! {Token::Word(w) => w}.map_with(|w, e| {
         (
-            Pattern::Pair(w, Box::new((Pattern::Word(w), e.span()))),
+            PairPattern {
+                key: w,
+                patt: ((Pattern::Word(w), e.span())),
+            },
             e.span(),
         )
     });
@@ -358,10 +412,12 @@ where
 
     let pair = select! {Token::Keyword(k) => k}
         .then(simple.clone())
-        .map_with(|(kw, expr), e| (Ast::Pair(kw, Box::new(expr)), e.span()));
+        .map_with(|(key, value), e| Pair { key, value });
 
-    let shorthand = select! {Token::Word(w) => w}
-        .map_with(|w, e| (Ast::Pair(w, Box::new((Ast::Word(w), e.span()))), e.span()));
+    let shorthand = select! {Token::Word(w) => w}.map_with(|w, e| Pair {
+        key: w,
+        value: ((Ast::Word(w), e.span())),
+    });
 
     let dict = pair
         .or(shorthand)
@@ -442,15 +498,10 @@ where
         .clone()
         .then_ignore(just(Token::Punctuation("->")))
         .then(expr.clone())
-        .map_with(|(patt, body), e| {
-            (
-                MatchClause {
-                    patt,
-                    guard: None,
-                    body,
-                },
-                e.span(),
-            )
+        .map_with(|(patt, body), _| MatchClause {
+            patt,
+            guard: None,
+            body,
         });
 
     let match_ = just(Token::Reserved("match"))
@@ -499,15 +550,10 @@ where
         .clone()
         .then_ignore(just(Token::Punctuation("->")))
         .then(nonbinding.clone())
-        .map_with(|(patt, body), e| {
-            (
-                MatchClause {
-                    patt,
-                    body,
-                    guard: None,
-                },
-                e.span(),
-            )
+        .map_with(|(patt, body), _| MatchClause {
+            patt,
+            body,
+            guard: None,
         })
         .labelled("function clause");
 

src/value.rs

@@ -1,39 +1,32 @@
 use crate::parser::*;
-use crate::spans::*;
 use imbl::*;
 use std::cell::RefCell;
 use std::fmt;
 use std::rc::Rc;
 
-#[derive(Clone, Debug, PartialEq)]
-pub struct Clause<'src> {
-    patt: Pattern<'src>,
-    span: Span,
-    body: Ast<'src>,
-}
-
 #[derive(Clone, Debug, PartialEq)]
 pub struct Fn<'src> {
-    name: &'src str,
-    span: Span,
-    body: Vec<Clause<'src>>,
+    pub name: &'src str,
+    pub body: &'src Vec<MatchClause<'src>>,
 }
 
 #[derive(Debug, PartialEq)]
 pub enum Value<'src> {
     Nil,
+    Placeholder,
     Boolean(bool),
     Number(f64),
     Keyword(&'src str),
     String(&'src str),
     // on the heap for now
     Tuple(Rc<Vec<Self>>),
+    Args(Rc<Vec<Self>>),
     // ref-counted, immutable, persistent
     List(Vector<Self>),
     // ref-counted, immutable, persistent
     Dict(HashMap<&'src str, Self>),
     Box(&'src str, Rc<RefCell<Self>>),
-    // Fn(Rc<Fn<'src>>),
+    Fn(Rc<Fn<'src>>),
     // Set(HashSet<Self>),
     // Sets are hard
     // Sets require Eq
@@ -55,9 +48,12 @@ impl<'src> Clone for Value<'src> {
             Value::Keyword(s) => Value::Keyword(s),
             Value::Number(n) => Value::Number(n.clone()),
             Value::Tuple(t) => Value::Tuple(t.clone()),
+            Value::Args(a) => Value::Args(a.clone()),
+            Value::Fn(f) => Value::Fn(f.clone()),
             Value::List(l) => Value::List(l.clone()),
             Value::Dict(d) => Value::Dict(d.clone()),
             Value::Box(name, b) => Value::Box(name, b.clone()),
+            Value::Placeholder => Value::Placeholder,
         }
     }
 }
@@ -70,8 +66,8 @@ impl<'src> fmt::Display for Value<'src> {
             Value::Number(n) => write!(f, "{}", n),
             Value::Keyword(k) => write!(f, ":{}", k),
             Value::String(s) => write!(f, "\"{}\"", s),
-            // Value::Fn(fun) => write!(f, "fn {}", fun.name),
-            Value::Tuple(t) => write!(
+            Value::Fn(fun) => write!(f, "fn {}", fun.name),
+            Value::Tuple(t) | Value::Args(t) => write!(
                 f,
                 "({})",
                 t.iter()
@@ -87,8 +83,16 @@ impl<'src> fmt::Display for Value<'src> {
                     .collect::<Vec<_>>()
                     .join(", ")
             ),
-            Value::Dict(d) => write!(f, "#{{{:?}}}", d),
+            Value::Dict(d) => write!(
+                f,
+                "#{{{}}}",
+                d.iter()
+                    .map(|(k, v)| format!(":{k} {v}"))
+                    .collect::<Vec<_>>()
+                    .join(", ")
+            ),
             Value::Box(name, b) => todo!(),
+            Value::Placeholder => write!(f, "_"),
         }
     }
 }

src/vm.rs

@@ -1,6 +1,8 @@
 use crate::parser::*;
 use crate::value::*;
+use imbl::HashMap;
 use imbl::Vector;
+use std::cell::RefCell;
 use std::rc::Rc;
 
 #[derive(Clone, Debug)]
@@ -48,7 +50,7 @@ where
     }
 }
 
-pub fn matchh<'src, 'a>(
+pub fn match_pattern<'src, 'a>(
     patt: &Pattern<'src>,
     val: &Value<'src>,
     ctx: &'a mut Vec<(&'src str, Value<'src>)>,
@@ -71,7 +73,7 @@ pub fn matchh<'src, 'a>(
             };
             let to = ctx.len();
             for i in 0..x.len() {
-                if let None = matchh(&x[i].0, &y[i], ctx) {
+                if let None = match_pattern(&x[i].0, &y[i], ctx) {
                     while ctx.len() > to {
                         ctx.pop();
                     }
@@ -86,7 +88,7 @@ pub fn matchh<'src, 'a>(
             };
             let to = ctx.len();
             for i in 0..x.len() {
-                if let None = matchh(&x[i].0, y.get(i).unwrap(), ctx) {
+                if let None = match_pattern(&x[i].0, y.get(i).unwrap(), ctx) {
                     while ctx.len() > to {
                         ctx.pop();
                     }
@@ -95,14 +97,60 @@ pub fn matchh<'src, 'a>(
             }
             Some(ctx)
         }
-        (Pattern::Pair(_, _), _) => todo!("dictionary patterns still to do"),
         (Pattern::Dict(_), _) => todo!("dictionary patterns still to do"),
         _ => None,
     }
 }
 
+pub fn match_clauses<'src, 'a>(
+    value: &Value<'src>,
+    clauses: &'src Vec<MatchClause<'src>>,
+    ctx: &'a mut Vec<(&'src str, Value<'src>)>,
+) -> Result<Value<'src>, LudusError> {
+    let to = ctx.len();
+    for MatchClause { patt, body, .. } in clauses.iter() {
+        if let Some(ctx) = match_pattern(&patt.0, value, ctx) {
+            let res = eval(&body.0, ctx);
+            while ctx.len() > to {
+                ctx.pop();
+            }
+            return res;
+        }
+    }
+    Err(LudusError {
+        msg: "no match".to_string(),
+    })
+}
+
+pub fn apply<'src, 'a>(
+    callee: Value<'src>,
+    caller: Value<'src>,
+    ctx: &'a mut Vec<(&'src str, Value<'src>)>,
+) -> Result<Value<'src>, LudusError> {
+    match (callee, caller) {
+        (Value::Keyword(kw), Value::Dict(dict)) => {
+            if let Some(val) = dict.get(kw) {
+                Ok(val.clone())
+            } else {
+                Ok(Value::Nil)
+            }
+        }
+        (Value::Dict(_dict), Value::Keyword(_kw)) => todo!(),
+        (Value::Fn(f), Value::Tuple(args)) => {
+            let args = Value::Tuple(args);
+            match_clauses(&args, f.body, ctx)
+        }
+        (Value::Fn(_f), Value::Args(_args)) => todo!(),
+        (_, Value::Keyword(_)) => Ok(Value::Nil),
+        (_, Value::Args(_)) => Err(LudusError {
+            msg: "you may only call a function".to_string(),
+        }),
+        _ => unreachable!(),
+    }
+}
+
 pub fn eval<'src, 'a>(
-    ast: &Ast<'src>,
+    ast: &'src Ast<'src>,
     ctx: &'a mut Vec<(&'src str, Value<'src>)>,
 ) -> Result<Value<'src>, LudusError> {
     match ast {
@@ -154,20 +202,57 @@ pub fn eval<'src, 'a>(
         }
         Ast::Let(patt, expr) => {
             let val = eval(&expr.0, ctx)?;
-            match matchh(&patt.0, &val, ctx) {
+            match match_pattern(&patt.0, &val, ctx) {
                 Some(_) => Ok(val),
                 None => Err(LudusError {
                     msg: "No match".to_string(),
                 }),
             }
         }
-        Ast::Placeholder => todo!(),
-        Ast::Error => todo!(),
-        Ast::Dict(_) => todo!(),
-        Ast::Arguments(_) => todo!(),
-        Ast::Pair(_, _) => todo!(),
-        Ast::Box(_, _) => todo!(),
-        Ast::Synthetic(_, _, _) => todo!(),
+        Ast::Placeholder => Ok(Value::Placeholder),
+        Ast::Error => unreachable!(),
+        Ast::Arguments(a) => {
+            let mut args = vec![];
+            for (arg, _) in a.iter() {
+                let arg = eval(&arg, ctx)?;
+                args.push(arg);
+            }
+            if args.iter().any(|arg| {
+                if let Value::Placeholder = arg {
+                    true
+                } else {
+                    false
+                }
+            }) {
+                Ok(Value::Args(Rc::new(args)))
+            } else {
+                Ok(Value::Tuple(Rc::new(args)))
+            }
+        }
+        Ast::Dict(pairs) => {
+            let mut dict = HashMap::new();
+            for Pair { key, value } in pairs {
+                let value = eval(&value.0, ctx)?;
+                dict.insert(*key, value);
+            }
+            Ok(Value::Dict(dict))
+        }
+        Ast::Box(name, expr) => {
+            let val = eval(&expr.0, ctx)?;
+            let boxed = Value::Box(name, Rc::new(RefCell::new(val)));
+            ctx.push((name, boxed.clone()));
+            Ok(boxed)
+        }
+        Ast::Synthetic(root, first, rest) => {
+            let root = eval(&root.0, ctx)?;
+            let first = eval(&first.0, ctx)?;
+            let mut curr = apply(root, first, ctx)?;
+            for term in rest.iter() {
+                let next = eval(&term.0, ctx)?;
+                curr = apply(curr, next, ctx)?;
+            }
+            Ok(curr)
+        }
         Ast::When(clauses) => {
             for clause in clauses.iter() {
                 let WhenClause { cond, body } = &clause.0;
@@ -179,8 +264,18 @@ pub fn eval<'src, 'a>(
                 msg: "no match".to_string(),
             });
         }
-        Ast::Match(_, _) => todo!(),
-        Ast::Fn(_, _) => todo!(),
+        Ast::Match(value, clauses) => {
+            let value = eval(&value.0, ctx)?;
+            match_clauses(&value, clauses, ctx)
+        }
+        Ast::Fn(name, clauses) => {
+            let the_fn = Value::Fn::<'src>(Rc::new(Fn::<'src> {
+                name,
+                body: clauses,
+            }));
+            ctx.push((name, the_fn.clone()));
+            Ok(the_fn)
+        }
         Ast::FnDeclaration(_) => todo!(),
         Ast::Panic(msg) => {
             let msg = eval(&msg.0, ctx)?;
@@ -201,12 +296,12 @@ pub fn eval<'src, 'a>(
                 }
             }
             for _ in 0..times_num {
-                let _ = eval(&body.0, ctx)?;
+                eval(&body.0, ctx)?;
             }
             Ok(Value::Nil)
         }
         Ast::Do(_) => todo!(),
-        Ast::Loop(_, _) => todo!(),
-        Ast::Recur(_) => todo!(),
+        // Ast::Loop(_, _) => todo!(),
+        // Ast::Recur(_) => todo!(),
     }
 }