Add dot syntax for associated functions

documentation/README.md

@@ -24,11 +24,11 @@ Syntax for Reid is very much inspired by rust, and examples of the language can
 be found in the [examples](../examples/)-folder.
 
 In Reid **modules** (or files) on the top-level are comprised of imports, type
-definitions, binop-definitions and functions.
+definitions, binop-definitions, functions and type-associated function blocks.
 
 In formal grammar
 ```bnf
-<module> :: (<import> | <type-definition> | <binop-definition> | <function>)*
+<module> :: (<import> | <type-definition> | <binop-definition> | <function> | <assoc-function-block>)*
 ```
 
 Table of Contents:
@@ -38,6 +38,7 @@ Table of Contents:
     - [Struct types](#struct-types)
 - [Binary operation Definitions](#binary-operation-definitions)
 - [Function definitions](#function-definition)
+  - [Associated functions](#associated-functions)
 - [Statement](#statement)
 - [Expression](#expression)
 
@@ -140,7 +141,7 @@ impl binop (lhs: u16) + (rhs: u32) -> u32 {
 
 ### Function Definition
 
-Rust syntax for defining functions is similar to rust. There are two types of functions:
+Reid syntax for defining functions is similar to rust. There are two types of functions:
 1. `extern` functions which are defined in another module, used to define functions from outside modules such as `libc`.
 2. `local` functions which are defined locally in the module in Reid. Their
    definition is contained within a `block` which contains a list of
@@ -153,8 +154,9 @@ In formal grammar:
 <local-function> :: [ "pub" ] "fn" <signature> <block>
 
 <signature> :: <ident> "(" [ <params> ] ")" [ "->" <type> ]
-<params> <param> ( "," <param> )*
-<param> :: <ident> ":" <type>
+<params> :: <param-or-self> ( "," <param> )*
+<param-or-self> = <param> | ( [ "&" [ "mut" ] ] "self")
+<param> :: (<ident> ":" <type>)
 <block> :: "{" <statement>* "}"
 ```
 
@@ -167,6 +169,27 @@ fn main() -> u8 {
 }
 ```
 
+#### Associated Functions
+
+Reid also has a very similar syntax for defining associated functions as Rust
+does. They are also the only types of functions where usage of initial
+"self"-param is allowed, referring to a potential self-type. Associated
+functions are functions that are defined within certain types such that you can
+have multiple functions of the same name, as long as they are associated with a
+different type. In formal grammar associated function blocks are:
+```bnf
+<assoc-function-block> :: "impl" <type> "{" <function-definition>* "}"
+```
+
+An example of such a block could be:
+```rust
+impl Test {
+    fn get_field(&self) -> u32 {
+        *self.field
+    }
+}
+```
+
 ### Statement
 
 Statements in Reid is how you tell the program to do anything. Currently supported statements include:
@@ -222,6 +245,8 @@ calls, literals, or if-expressions. Types of supported expressions include:
 - **Binary operations** (such as add/sub/mult)
 - **Unary operations** (such as !value or -value)
 - **Function calls**, to invoke a predefined function with given parameters
+- **Associated function calls**, to invoke a predefined function on a certain
+  *associated type* with given parameters.
 - **Block-expressions**, which can return a value to the higher-level expression
   if they have a statement with a soft-return. Otherwise they return void.
 - **If-expressions**, which can execute one of two expressions depending on the
@@ -238,8 +263,8 @@ In formal grammar:
     <array> | <struct> |
     <indexing> | <accessing> |
     <binary-exp> | <unary-exp> |
-    <function-call> | <block> |
-    <if-expr> | <cast> |
+    <function-call> | <assoc-function-call>
+    <block> | <if-expr> | <cast> |
     ( "(" <expression> ")" )
 
 <variable> :: <ident>
@@ -253,6 +278,7 @@ In formal grammar:
 <binary-exp> :: <expression> <binop> <expression>
 <unary-exp> :: <unary> <expression>
 <function-call> :: <expression> "(" [ <expression> ( "," <expression> )* ] ")"
+<assoc-function-call> :: <type> "::" <function-call>
 <if-expr> :: "if" <expression> <expression> [ "else" <expression> ]
 <cast> :: <expression> "as" <type>
 ```
@@ -269,6 +295,7 @@ test.first // Accessing
 7 + value // Binop
 !bool_value // Unary
 func(value, 14) // Function call
+Test::get_field(&test); // Associated function call
 if varname {} else {} // If-expression
 value as u32 // cast
 (value + 2) // Binop within parenthesis

examples/associated_functions_shorthand.reid

@@ -0,0 +1,27 @@
+import std::print;
+import std::from_str;
+import std::String;
+
+struct Otus {
+    field: u32,
+}
+
+impl Otus {
+    fn test(self) -> u32 {
+        self.field
+    }
+}
+
+impl i32 {
+    fn test(self) -> u32 {
+        43
+    }
+}
+
+fn main() -> u32 {
+    let otus = Otus { field: 17 };
+    print(from_str("otus: ") + otus.test() as u64);
+
+
+    return otus.test();
+}

reid/src/ast/mod.rs

@@ -89,6 +89,8 @@ pub enum ExpressionKind {
     Indexed(Box<Expression>, Box<Expression>),
     /// Struct-accessed, e.g. <expr>.<expr>
     Accessed(Box<Expression>, String),
+    /// Associated function call, but with a shorthand
+    AccessCall(Box<Expression>, Box<FunctionCallExpression>),
     Binop(BinaryOperator, Box<Expression>, Box<Expression>),
     FunctionCall(Box<FunctionCallExpression>),
     AssociatedFunctionCall(Type, Box<FunctionCallExpression>),

reid/src/ast/parse.rs

@@ -358,12 +358,20 @@ impl Parse for PrimaryExpression {
                         stream.get_range().unwrap(),
                     );
                 }
-                ValueIndex::Struct(StructValueIndex(name)) => {
+                ValueIndex::Dot(val) => match val {
+                    DotIndexKind::StructValueIndex(name) => {
                         expr = Expression(
                             ExpressionKind::Accessed(Box::new(expr), name),
                             stream.get_range().unwrap(),
                         );
                     }
+                    DotIndexKind::FunctionCall(function_call_expression) => {
+                        expr = Expression(
+                            ExpressionKind::AccessCall(Box::new(expr), Box::new(function_call_expression)),
+                            stream.get_range().unwrap(),
+                        );
+                    }
+                },
             }
         }
 
@@ -473,27 +481,35 @@ impl Parse for BinaryOperator {
 impl Parse for FunctionCallExpression {
     fn parse(mut stream: TokenStream) -> Result<Self, Error> {
         if let Some(Token::Identifier(name)) = stream.next() {
-            stream.expect(Token::ParenOpen)?;
-
-            let mut args = Vec::new();
-
-            if let Ok(exp) = stream.parse() {
-                args.push(exp);
-
-                while stream.expect(Token::Comma).is_ok() {
-                    args.push(stream.parse()?);
-                }
-            }
-
-            stream.expect(Token::ParenClose)?;
-
-            Ok(FunctionCallExpression(name, args, stream.get_range().unwrap()))
+            let args = stream.parse::<FunctionArgs>()?;
+            Ok(FunctionCallExpression(name, args.0, stream.get_range().unwrap()))
         } else {
             Err(stream.expected_err("identifier")?)
         }
     }
 }
 
+#[derive(Debug)]
+pub struct FunctionArgs(Vec<Expression>);
+
+impl Parse for FunctionArgs {
+    fn parse(mut stream: TokenStream) -> Result<Self, Error> {
+        stream.expect(Token::ParenOpen)?;
+
+        let mut params = Vec::new();
+        if let Ok(exp) = stream.parse() {
+            params.push(exp);
+
+            while stream.expect(Token::Comma).is_ok() {
+                params.push(stream.parse()?);
+            }
+        }
+        stream.expect(Token::ParenClose)?;
+
+        Ok(FunctionArgs(params))
+    }
+}
+
 impl Parse for IfExpression {
     fn parse(mut stream: TokenStream) -> Result<Self, Error> {
         stream.expect(Token::If)?;
@@ -766,14 +782,14 @@ impl<T: Parse + std::fmt::Debug> Parse for NamedField<T> {
 #[derive(Debug, Clone)]
 pub enum ValueIndex {
     Array(ArrayValueIndex),
-    Struct(StructValueIndex),
+    Dot(DotIndexKind),
 }
 
 impl Parse for ValueIndex {
     fn parse(mut stream: TokenStream) -> Result<Self, Error> {
         match stream.peek() {
             Some(Token::BracketOpen) => Ok(ValueIndex::Array(stream.parse()?)),
-            Some(Token::Dot) => Ok(ValueIndex::Struct(stream.parse()?)),
+            Some(Token::Dot) => Ok(ValueIndex::Dot(stream.parse()?)),
             _ => Err(stream.expecting_err("value or struct index")?),
         }
     }
@@ -792,13 +808,24 @@ impl Parse for ArrayValueIndex {
 }
 
 #[derive(Debug, Clone)]
-pub struct StructValueIndex(String);
+pub enum DotIndexKind {
+    StructValueIndex(String),
+    FunctionCall(FunctionCallExpression),
+}
 
-impl Parse for StructValueIndex {
+impl Parse for DotIndexKind {
     fn parse(mut stream: TokenStream) -> Result<Self, Error> {
         stream.expect(Token::Dot)?;
         if let Some(Token::Identifier(name)) = stream.next() {
-            Ok(StructValueIndex(name))
+            if let Ok(args) = stream.parse::<FunctionArgs>() {
+                Ok(Self::FunctionCall(FunctionCallExpression(
+                    name,
+                    args.0,
+                    stream.get_range_prev().unwrap(),
+                )))
+            } else {
+                Ok(Self::StructValueIndex(name))
+            }
         } else {
             return Err(stream.expected_err("struct index (number)")?);
         }

reid/src/ast/process.rs

@@ -422,6 +422,19 @@ impl ast::Expression {
                     meta: fn_call_expr.2.as_meta(module_id),
                 },
             ),
+            ast::ExpressionKind::AccessCall(expression, fn_call_expr) => {
+                let mut params: Vec<_> = fn_call_expr.1.iter().map(|e| e.process(module_id)).collect();
+                params.insert(0, expression.process(module_id));
+                mir::ExprKind::AssociatedFunctionCall(
+                    mir::TypeKind::Vague(mir::VagueType::Unknown),
+                    mir::FunctionCall {
+                        name: fn_call_expr.0.clone(),
+                        return_type: mir::TypeKind::Vague(mir::VagueType::Unknown),
+                        parameters: params,
+                        meta: fn_call_expr.2.as_meta(module_id),
+                    },
+                )
+            }
         };
 
         mir::Expression(kind, self.1.as_meta(module_id))

reid/src/mir/typecheck/mod.rs

@@ -82,6 +82,8 @@ pub enum ErrorKind {
     BinaryOpAlreadyDefined(BinaryOperator, TypeKind, TypeKind),
     #[error("Binary operation {0} between {1} and {2} is not defined")]
     InvalidBinop(BinaryOperator, TypeKind, TypeKind),
+    #[error("Could not infer type for {0:?}. Try adding type annotations.")]
+    CouldNotInferType(String),
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -294,13 +296,13 @@ impl TypeKind {
         }
     }
 
-    pub(super) fn assert_known(&self, refs: &TypeRefs, state: &TypecheckPassState) -> Result<TypeKind, ErrorKind> {
-        self.is_known(refs, state).map(|_| self.clone())
+    pub(super) fn assert_known(&self, state: &TypecheckPassState) -> Result<TypeKind, ErrorKind> {
+        self.is_known(state).map(|_| self.clone())
     }
 
-    pub(super) fn is_known(&self, refs: &TypeRefs, state: &TypecheckPassState) -> Result<(), ErrorKind> {
+    pub(super) fn is_known(&self, state: &TypecheckPassState) -> Result<(), ErrorKind> {
         match &self {
-            TypeKind::Array(type_kind, _) => type_kind.as_ref().is_known(refs, state),
+            TypeKind::Array(type_kind, _) => type_kind.as_ref().is_known(state),
             TypeKind::CustomType(custom_type_key) => {
                 state
                     .scope
@@ -311,9 +313,9 @@ impl TypeKind {
                         state.module_id.unwrap(),
                     ))
             }
-            TypeKind::Borrow(type_kind, _) => type_kind.is_known(refs, state),
-            TypeKind::UserPtr(type_kind) => type_kind.is_known(refs, state),
-            TypeKind::CodegenPtr(type_kind) => type_kind.is_known(refs, state),
+            TypeKind::Borrow(type_kind, _) => type_kind.is_known(state),
+            TypeKind::UserPtr(type_kind) => type_kind.is_known(state),
+            TypeKind::CodegenPtr(type_kind) => type_kind.is_known(state),
             TypeKind::Vague(vague_type) => Err(ErrorKind::TypeIsVague(*vague_type)),
             _ => Ok(()),
         }

reid/src/mir/typecheck/typecheck.rs

@@ -112,7 +112,7 @@ impl BinopDefinition {
     fn typecheck(&mut self, typerefs: &TypeRefs, state: &mut TypecheckPassState) -> Result<TypeKind, ErrorKind> {
         for param in vec![&self.lhs, &self.rhs] {
             let param_t = state.or_else(
-                param.1.assert_known(typerefs, state),
+                param.1.assert_known(state),
                 TypeKind::Vague(Vague::Unknown),
                 self.signature(),
             );
@@ -130,7 +130,7 @@ impl BinopDefinition {
             state.ok(res, self.signature());
         }
 
-        let return_type = self.return_type.clone().assert_known(typerefs, state)?;
+        let return_type = self.return_type.clone().assert_known(state)?;
 
         state.scope.return_type_hint = Some(self.return_type.clone());
         let inferred = self
@@ -150,7 +150,7 @@ impl FunctionDefinition {
     fn typecheck(&mut self, typerefs: &TypeRefs, state: &mut TypecheckPassState) -> Result<TypeKind, ErrorKind> {
         for param in &self.parameters {
             let param_t = state.or_else(
-                param.1.assert_known(typerefs, state),
+                param.1.assert_known(state),
                 TypeKind::Vague(Vague::Unknown),
                 self.signature(),
             );
@@ -168,7 +168,7 @@ impl FunctionDefinition {
             state.ok(res, self.signature());
         }
 
-        let return_type = self.return_type.clone().assert_known(typerefs, state)?;
+        let return_type = self.return_type.clone().assert_known(state)?;
         let inferred = self.kind.typecheck(typerefs, state, Some(self.return_type.clone()));
 
         match inferred {
@@ -327,7 +327,7 @@ impl Block {
                 }
                 StmtKind::While(WhileStatement { condition, block, meta }) => {
                     let condition_ty = condition.typecheck(&mut state, typerefs, HintKind::Coerce(TypeKind::Bool))?;
-                    if condition_ty.assert_known(typerefs, &state)? != TypeKind::Bool {
+                    if condition_ty.assert_known(&state)? != TypeKind::Bool {
                         state.note_errors(&vec![ErrorKind::TypesIncompatible(condition_ty, TypeKind::Bool)], *meta);
                     }
 

reid/src/mir/typecheck/typeinference.rs

@@ -595,6 +595,19 @@ impl Expression {
                 Ok(type_refs.from_type(type_kind).unwrap())
             }
             ExprKind::AssociatedFunctionCall(type_kind, function_call) => {
+                if type_kind.is_known(state).is_err() {
+                    let first_param = function_call
+                        .parameters
+                        .get_mut(0)
+                        .expect("Unknown-type associated function NEEDS to always have at least one parameter!");
+                    let param_ty = first_param.infer_types(state, type_refs).unwrap().resolve_deep();
+                    *type_kind = state.or_else(
+                        param_ty.ok_or(ErrorKind::CouldNotInferType(format!("{}", first_param))),
+                        Void,
+                        first_param.1,
+                    );
+                }
+
                 // Get function definition and types
                 let fn_call = state
                     .scope