new function parsing

src/executor.rs

@@ -232,31 +232,11 @@ where
                 }
             },
             ParseTree::FunctionDefinition(func, scope) => {
-                let ident = func.name.clone().unwrap();
-                
-                let existing = locals.get(&ident)
-                    .or(self.globals.get(&ident));
-            
-                match existing {
-                    Some(Object::Function(f)) => {
-                        if f.body.is_some() || f.arg_names.is_some() {
-                            return Err(RuntimeError::ImmutableError(ident.clone()));
-                        }
-                    
-                        let new_func = Function::named(func.name.unwrap().as_str(), func.t.clone(), func.arg_names.clone(), func.body.clone());
-
                 let locals = locals.to_mut();
-                        locals.insert(ident.clone(), Object::Function(new_func));
+
+                locals.insert(func.name.clone().unwrap(), Object::Function(func));
 
                 self.exec(scope, &mut Cow::Borrowed(&locals))
-                    }
-                    Some(Object::Variable(_)) => Err(RuntimeError::ImmutableError(ident.clone())),
-                    None => {
-                        let locals = locals.to_mut();
-                        locals.insert(ident.clone(), Object::Function(func));
-                        self.exec(scope, &mut Cow::Borrowed(&locals))
-                    }
-                }
             },
             ParseTree::Compose(x, y) => {
                 self.exec(x, locals)?;
@@ -296,6 +276,9 @@ where
                     Some(Object::Function(f)) => {
                         let locals = locals.to_mut();
 
+                        assert!(f.arg_names.is_some());
+                        assert!(f.body.is_some());
+
                         for ((t, name), tree) in std::iter::zip(std::iter::zip(f.t.1, f.arg_names.unwrap()), args) {
                             let v = self.exec(Box::new(tree), &mut Cow::Borrowed(locals))?;
 
@@ -369,18 +352,7 @@ where
                     Ok(Value::Nil)
                 }
             }
-            ParseTree::FunctionDeclaration(func, scope) => {
+            ParseTree::LambdaDefinition(func) => todo!(),
-                let locals = locals.to_mut();
-                let name = func.name.clone().unwrap();
-
-                if locals.contains_key(&name) {
-                    Err(RuntimeError::ImmutableError(name.clone()))
-                } else {
-                    locals.insert(name, Object::Function(func));
-                    self.exec(scope, &mut Cow::Borrowed(&locals))
-                }
-            }
-            ParseTree::LambdaDefinition(func) => Ok(Value::Function(func)),
         }
     }
 }

src/parser.rs

@@ -5,13 +5,14 @@ use std::error;
 use std::collections::HashMap;
 use std::fmt::Display;
 use std::borrow::Cow;
+use std::iter::Peekable;
 
 #[derive(Debug)]
 pub enum ParseError {
     NoInput,
     UnexpectedEndInput,
     IdentifierUndefined(String),
-    InvalidIdentifier,
+    InvalidIdentifier(Token),
     FunctionUndefined(String),
     VariableUndefined(String),
     UnmatchedArrayClose,
@@ -25,7 +26,7 @@ impl Display for ParseError {
         match self {
             ParseError::UnexpectedEndInput => write!(f, "Input ended unexpectedly"),
             ParseError::IdentifierUndefined(name) => write!(f, "Undefined variable `{name}`"),
-            ParseError::InvalidIdentifier => write!(f, "Invalid identifier"),
+            ParseError::InvalidIdentifier(t) => write!(f, "Invalid identifier `{t:?}`"),
             ParseError::FunctionUndefined(name) => write!(f, "Undefined function `{name}`"),
             ParseError::VariableUndefined(name) => write!(f, "Undefined variable `{name}`"),
             ParseError::NoInput => write!(f, "No input given"),
@@ -64,7 +65,6 @@ pub(crate) enum ParseTree {
     Equ(String, Box<ParseTree>, Box<ParseTree>),
     LazyEqu(String, Box<ParseTree>, Box<ParseTree>),
     FunctionDefinition(Function, Box<ParseTree>),
-    FunctionDeclaration(Function, Box<ParseTree>),
     LambdaDefinition(Function),
 
     // Functional Operations
@@ -116,7 +116,7 @@ macro_rules! three_arg {
 
 impl ParseTree {
     fn parse<I>(
-        tokens: &mut I,
+        tokens: &mut Peekable<I>,
         globals: &HashMap<String, Function>,
         locals: &mut Cow<HashMap<String, Function>>) -> Result<Self, ParseError>
     where
@@ -165,63 +165,32 @@ impl ParseTree {
                                         _ => panic!("Operator literally changed under your nose"),
                                     }
                                 } else {
-                                    Err(ParseError::InvalidIdentifier)
+                                    Err(ParseError::InvalidIdentifier(token))
                                 }
                             }
-                            Op::FunctionDefine(nargs) => {
+                            Op::FunctionDefine(arg_count) => {
-                                let token = tokens.next()
+                                let mut f = ParseTree::parse_function(tokens, arg_count)?;
-                                    .ok_or(ParseError::UnexpectedEndInput)?
-                                    .map_err(|e| ParseError::TokenizeError(e))?;
 
-                                if let Token::Identifier(ident) = token {
+                                assert!(f.arg_names.is_some());
-                                    let args: Vec<String> = tokens.take(nargs)
+                                assert!(f.name.is_some());
-                                        .map(|token| match token {
+                                assert!(f.body.is_none());
-                                            Ok(Token::Identifier(ident)) => Ok(ident),
-                                            Ok(_) => Err(ParseError::InvalidIdentifier),
-                                            Err(e) => Err(ParseError::TokenizeError(e)),
-                                        })
-                                        .collect::<Result<Vec<_>, ParseError>>()?;
 
-                                    let f = if locals.contains_key(&ident) {
+                                if locals.contains_key(&f.name.clone().unwrap()) {
-                                        let locals = locals.to_mut();
+                                    return Err(ParseError::ImmutableError(f.name.unwrap()));
-                                        let f = locals.get(&ident).unwrap();
-                                        let f = f.clone();
-
-                                        // iterate over f's types and push them
-                                        for (t, name) in std::iter::zip(f.t.1.clone(), args.clone()) {
-                                            match t {
-                                                Type::Function(finner) => {
-                                                    locals.insert(name.clone(), Function::named(&name, finner, None, None));
                                 }
-                                                _ => (),
-                                            }
-                                        }
-
-                                        Function::named(
-                                            &ident,
-                                            f.t.clone(),
-                                            Some(args),
-                                            Some(Box::new(ParseTree::parse(tokens, globals, &mut Cow::Borrowed(&locals))?)))
-                                    } else {
-                                        let f = Function::named(
-                                            &ident,
-                                            FunctionType(Box::new(Type::Any), args.iter().map(|_| Type::Any).collect()),
-                                            Some(args),
-                                            Some(Box::new(ParseTree::parse(tokens, globals, &mut Cow::Borrowed(&locals))?)));
 
                                 let locals = locals.to_mut();
 
-                                        locals.insert(ident.clone(), f.clone());
+                                // recursion requires that f's prototype is present in locals
+                                locals.insert(f.name.clone().unwrap(), f.clone());
 
-                                        f
+                                f.body = Some(Box::new(ParseTree::parse(tokens, globals, &mut Cow::Borrowed(&locals))?));
-                                    };
+                                assert!(f.body.is_some());
 
-                                    Ok(ParseTree::FunctionDefinition(f,
+                                println!("{:?} = {:?}", f.name, f);
-                                        Box::new(ParseTree::parse(tokens, globals, locals)?)))
+
-                                } else {
+                                Ok(ParseTree::FunctionDefinition(f, Box::new(ParseTree::parse(tokens, globals, &mut Cow::Borrowed(&locals))?)))
-                                    Err(ParseError::InvalidIdentifier)
+                            },
-                                }
-                            }
                             Op::Compose => two_arg!(Compose, tokens, globals, locals),
                             Op::Id => one_arg!(Id, tokens, globals, locals),
                             Op::If => two_arg!(If, tokens, globals, locals),
@@ -273,69 +242,9 @@ impl ParseTree {
                             Op::NotEqualTo => two_arg!(NotEqualTo, tokens, globals, locals),
                             Op::And => two_arg!(And, tokens, globals, locals),
                             Op::Or => two_arg!(Or, tokens, globals, locals),
-                            Op::FunctionDeclare(arg_count) => {
+                            Op::LambdaDefine(_arg_count) => todo!(),
-                                let name = match tokens.next()
+                            Op::NonCall => todo!(),
-                                    .ok_or(ParseError::UnexpectedEndInput)?
+                            op => Err(ParseError::UnwantedToken(Token::Operator(op))),
-                                    .map_err(|e| ParseError::TokenizeError(e))?
-                                {
-                                        Token::Identifier(x) => x,
-                                        _ => return Err(ParseError::InvalidIdentifier),
-                                };
-
-                                let args: Vec<Type> = (0..arg_count)
-                                    .map(|_| Self::parse_type(tokens))
-                                    .collect::<Result<_, ParseError>>()?;
-
-                                let rett = Self::parse_type(tokens)?;
-
-                                if locals.contains_key(&name) {
-                                    println!("{name} already found: {locals:?}");
-                                    return Err(ParseError::ImmutableError(name.clone()));
-                                }
-
-                                let f = Function::named(
-                                    &name,
-                                    FunctionType(Box::new(rett), args),
-                                    None,
-                                    None);
-
-                                let locals = locals.to_mut();
-
-                                locals.insert(name, f.clone());
-
-                                Ok(ParseTree::FunctionDeclaration(
-                                    f,
-                                    Box::new(ParseTree::parse(tokens, globals, &mut Cow::Borrowed(&*locals))?)))
-                            }
-                            Op::LambdaDefine(arg_count) => {
-                                let args: Vec<String> = tokens.take(arg_count)
-                                    .map(|token| match token {
-                                        Ok(Token::Identifier(ident)) => Ok(ident),
-                                        Ok(_) => Err(ParseError::InvalidIdentifier),
-                                        Err(e) => Err(ParseError::TokenizeError(e)),
-                                    })
-                                    .collect::<Result<Vec<_>, ParseError>>()?;
-
-                                Ok(ParseTree::LambdaDefinition(
-                                    Function::lambda(
-                                        FunctionType(Box::new(Type::Any), args.clone().into_iter().map(|_| Type::Any).collect()),
-                                        args,
-                                        Some(Box::new(ParseTree::parse(tokens, globals, &mut Cow::Borrowed(&*locals))?)))))
-                            }
-                            Op::NonCall => {
-                                let ident = match tokens.next().ok_or(ParseError::UnexpectedEndInput)?
-                                    .map_err(|e| ParseError::TokenizeError(e))?
-                                {
-                                    Token::Identifier(x) => x,
-                                    _ => return Err(ParseError::InvalidIdentifier),
-                                };
-
-                                if let Some(f) = locals.clone().get(&ident).or(globals.clone().get(&ident)).cloned() {
-                                    Ok(ParseTree::Constant(Value::Function(f)))
-                                } else {
-                                    Err(ParseError::FunctionUndefined(ident.clone()))
-                                }
-                            }
                         }
                     }
                     t => Err(ParseError::UnwantedToken(t)),
@@ -346,6 +255,92 @@ impl ParseTree {
         }
     }
 
+    fn parse_function<I>(tokens: &mut Peekable<I>, arg_count: usize) -> Result<Function, ParseError>
+    where
+        I: Iterator<Item = Result<Token, TokenizeError>>,
+    {
+        let name = Self::get_identifier(tokens.next())?;
+        let (t, args) = Self::parse_function_declaration(tokens, arg_count)?;
+
+        Ok(Function::named(&name, t, Some(args), None))
+    }
+
+    fn parse_function_declaration<I>(tokens: &mut Peekable<I>, arg_count: usize) -> Result<(FunctionType, Vec<String>), ParseError>
+    where
+        I: Iterator<Item = Result<Token, TokenizeError>>
+    {
+        let args: Vec<(Type, String)> = (0..arg_count)
+            .map(|_| Self::parse_function_declaration_parameter(tokens))
+            .collect::<Result<_, _>>()?;
+
+        
+        let (types, names): (Vec<_>, Vec<_>) = args.into_iter().unzip();
+        let mut ret = Type::Any;
+        
+        if let Some(t) = tokens.next_if(|x| matches!(x, Ok(Token::Operator(Op::Arrow))))
+        {
+            if let Err(e) = t {
+                return Err(ParseError::TokenizeError(e));
+            }
+            
+            ret = Self::parse_type(tokens)?;
+        }
+
+        Ok((FunctionType(Box::new(ret), types), names))
+    }
+
+    fn parse_function_declaration_parameter<I>(mut tokens: &mut Peekable<I>) -> Result<(Type, String), ParseError>
+    where
+        I: Iterator<Item = Result<Token, TokenizeError>>
+    {
+        match tokens.next() {
+            // untyped variable
+            Some(Ok(Token::Identifier(x))) => Ok((Type::Any, x)),
+
+            // typed variable
+            Some(Ok(Token::Operator(Op::TypeDeclaration))) => {
+                let name = Self::get_identifier(tokens.next())?;
+                let t = Self::parse_type(&mut tokens)?;
+
+                Ok((t, name))
+            }
+
+            // untyped function (all args Any, return type Any)
+            Some(Ok(Token::Operator(Op::FunctionDefine(n)))) => {
+                let name = Self::get_identifier(tokens.next())?;
+                let args = (0..n).map(|_| Type::Any).collect();
+
+                Ok((Type::Function(FunctionType(Box::new(Type::Any), args)), name))
+            }
+
+            // typed function
+            Some(Ok(Token::Operator(Op::FunctionDeclare(n)))) => {
+                let name = Self::get_identifier(tokens.next())?;
+                let args = (0..n).map(|_| Self::parse_type(&mut tokens)).collect::<Result<_, _>>()?;
+                let mut ret = Type::Any;
+
+                // this is annoying
+                // inside of the next_if closure, we already can know that its an error
+                // and return it, but we cannot return out of a closure
+                if let Some(t) = tokens.next_if(|x| matches!(x, Ok(Token::Operator(Op::Arrow))))
+                {
+                    // so we just check for an error here. this is the only reason t exists.
+                    if let Err(e) = t {
+                        return Err(ParseError::TokenizeError(e));
+                    }
+
+                    ret = Self::parse_type(&mut tokens)?;
+                }
+
+                Ok((Type::Function(FunctionType(Box::new(ret), args)), name))
+            }
+
+            Some(Ok(t)) => Err(ParseError::UnwantedToken(t)),
+            Some(Err(e)) => Err(ParseError::TokenizeError(e)),
+            None => Err(ParseError::UnexpectedEndInput),
+        }
+    }
+
     fn parse_type<I>(tokens: &mut I) -> Result<Type, ParseError>
     where
         I: Iterator<Item = Result<Token, TokenizeError>>,
@@ -375,6 +370,16 @@ impl ParseTree {
             None => Err(ParseError::UnexpectedEndInput),
         }
     }
+
+    fn get_identifier(t: Option<Result<Token, TokenizeError>>) -> Result<String, ParseError> {
+        match t.ok_or(ParseError::UnexpectedEndInput)?
+            .map_err(|e| ParseError::TokenizeError(e))
+        {
+            Ok(Token::Identifier(ident)) => Ok(ident),
+            Ok(t) => Err(ParseError::InvalidIdentifier(t)),
+            Err(e) => Err(e),
+        }
+    }
 }
 
 /// Parses input tokens and produces ParseTrees for an Executor
@@ -418,7 +423,7 @@ impl<I: Iterator<Item = Result<Token, TokenizeError>>> Iterator for Parser<I> {
     type Item = Result<ParseTree, ParseError>;
 
     fn next(&mut self) -> Option<Self::Item> {
-        let tree = ParseTree::parse(&mut self.tokens, &self.globals, &mut Cow::Borrowed(&self.locals));
+        let tree = ParseTree::parse(&mut self.tokens.by_ref().peekable(), &self.globals, &mut Cow::Borrowed(&self.locals));
 
         match tree {
             Ok(tree) => Some(Ok(tree)),

src/tokenizer.rs

@@ -41,7 +41,7 @@ impl Display for TokenizeError {
 
 impl error::Error for TokenizeError {}
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub(crate) enum Op {
     Add,
     Sub,
@@ -51,9 +51,11 @@ pub(crate) enum Op {
     Equ,
     Mod,
     LazyEqu,
+    TypeDeclaration,
     FunctionDefine(usize),
     FunctionDeclare(usize),
     LambdaDefine(usize),
+    Arrow,
     Compose,
     Id,
     If,
@@ -169,9 +171,11 @@ impl<R: BufRead> Tokenizer<R> {
             ("%", Op::Mod),
             ("=", Op::Equ),
             (".", Op::LazyEqu),
+            ("?.", Op::TypeDeclaration),
             (":", Op::FunctionDefine(1)),
             ("?:", Op::FunctionDeclare(1)),
             (";", Op::LambdaDefine(1)),
+            ("->", Op::Arrow),
             ("~", Op::Compose),
             (",", Op::Id),
             ("?", Op::If),
@@ -262,16 +266,6 @@ impl<R: BufRead> Tokenizer<R> {
                         if let Some(op) = possible.get(token.as_str()) {
                             self.tokens.push_back(Ok(Token::Operator(match op {
                                 // special handling for "dynamic" operators
-                                Op::FunctionDeclare(n) => {
-                                    let count = match get_dot_count(&mut iter) {
-                                        Some(count) => count,
-                                        None => {
-                                            self.tokens.push_back(Err(TokenizeError::InvalidDynamicOperator(token)));
-                                            return;
-                                        }
-                                    };
-                                    Op::FunctionDeclare(n + count)
-                                }
                                 Op::FunctionDefine(n) => {
                                     let count = match get_dot_count(&mut iter) {
                                         Some(count) => count,
@@ -282,6 +276,16 @@ impl<R: BufRead> Tokenizer<R> {
                                     };
                                     Op::FunctionDefine(n + count)
                                 }
+                                Op::FunctionDeclare(n) => {
+                                    let count = match get_dot_count(&mut iter) {
+                                        Some(count) => count,
+                                        None => {
+                                            self.tokens.push_back(Err(TokenizeError::InvalidDynamicOperator(token)));
+                                            return;
+                                        }
+                                    };
+                                    Op::FunctionDeclare(n + count)
+                                }
                                 Op::LambdaDefine(n) => {
                                     let count = match get_dot_count(&mut iter) {
                                         Some(count) => count,
@@ -314,7 +318,42 @@ impl<R: BufRead> Tokenizer<R> {
                             Some(c) => c,
                             None => {
                                 // at this point, token must be in the hashmap possible, otherwise it wouldnt have any matches
-                                self.tokens.push_back(Ok(Token::Operator(possible.get(token.as_str()).unwrap().clone())));
+                                self.tokens.push_back(Ok(Token::Operator(match possible.get(token.as_str()).unwrap() {
+                                    // special handling for "dynamic" operators
+                                    Op::FunctionDefine(n) => {
+                                        let count = match get_dot_count(&mut iter) {
+                                            Some(count) => count,
+                                            None => {
+                                                self.tokens.push_back(Err(TokenizeError::InvalidDynamicOperator(token)));
+                                                return;
+                                            }
+                                        };
+                                        println!("{n} + {count}");
+    
+                                        Op::FunctionDefine(n + count)
+                                    }
+                                    Op::FunctionDeclare(n) => {
+                                        let count = match get_dot_count(&mut iter) {
+                                            Some(count) => count,
+                                            None => {
+                                                self.tokens.push_back(Err(TokenizeError::InvalidDynamicOperator(token)));
+                                                return;
+                                            }
+                                        };
+                                        Op::FunctionDeclare(n + count)
+                                    }
+                                    Op::LambdaDefine(n) => {
+                                        let count = match get_dot_count(&mut iter) {
+                                            Some(count) => count,
+                                            None => {
+                                                self.tokens.push_back(Err(TokenizeError::InvalidDynamicOperator(token)));
+                                                return;
+                                            }
+                                        };
+                                        Op::LambdaDefine(n + count)
+                                    }
+                                    op => op.clone(),
+                                })));
                                 break;
                             }
                         };
@@ -374,7 +413,7 @@ mod tests {
 
     #[test]
     fn uwu() {
-        let program = "?:. apply : Any Any Any Any :. apply f x f x : id x x apply ; x id x 12";
+        let program = ":. add x y + x y";
 
         let tokens: Vec<Token> = Tokenizer::from_str(program).unwrap().collect::<Result<_, TokenizeError>>().unwrap();