added a lot of work in progress, but also a symbol table. Means I could refactor a lot of stuff and remove code. The symbol table is a global storage for vars, functions and objects. Helps with type inference and checking on external symbols

README.md

@@ -112,10 +112,10 @@ fn get(path: string, headers: map, query: map) -> string:
 * guards: this will be the way to deal with input
 ```
 fn get() -> [Customer] | Customer? | ():
-    | /. -> service.get_all()
+    | / -> service.get_all()
-    | /./{uuid} -> service.get(uuid)?
+    | /{uuid} -> service.get(uuid)?
-    | /.?{query.firstname} -> service.get_by_firstname(fname)?
+    | ?{query.firstname} -> service.get_by_firstname(fname)?
-    | /.?{query.last_name} -> service.get_by_lastname(lname)?
+    | ?{query.last_name} -> service.get_by_lastname(lname)?
     | _ -> 404
 ```
 * this may also require ADT's...

source/hello/web.crud

@@ -1,2 +1,6 @@
+object Person:
+    name: string
+
 fn get(path: string) -> string:
-    service.add("hello", path)
+    let p = Person(name: path)
+    service.add("hello", p.name)

src/ast_compiler.rs

@@ -1,4 +1,6 @@
-use crate::ast_compiler::Expression::{FunctionCall, Literal, RemoteFunctionCall, Variable};
+use crate::ast_compiler::Expression::{
+    FunctionCall, NamedParameter, Stop, Variable,
+};
 use crate::errors::CompilerError::{
     self, Expected, IncompatibleTypes, ParseError, TooManyParameters, TypeError,
     UndeclaredVariable, UnexpectedIndent, UninitializedVariable,
@@ -14,7 +16,6 @@ use crate::tokens::TokenType::{
 use crate::tokens::{Token, TokenType};
 use crate::value::Value;
 use log::debug;
-use std::collections::HashMap;
 
 pub fn compile(
     path: Option<&str>,
@@ -36,9 +37,7 @@ struct AstCompiler {
     tokens: Vec<Token>,
     current: usize,
     had_error: bool,
-    vars: Vec<Expression>,
     indent: Vec<usize>,
-    functions: HashMap<String, Function>,
 }
 
 impl AstCompiler {
@@ -47,9 +46,7 @@ impl AstCompiler {
             tokens,
             current: 0,
             had_error: false,
-            vars: vec![],
             indent: vec![0],
-            functions: HashMap::new(),
         }
     }
 
@@ -58,7 +55,6 @@ impl AstCompiler {
     }
 
     fn compile_tokens(&mut self) -> Result<Vec<Statement>, CompilerErrorAtLine> {
-        self.collect_functions()?;
         self.reset();
         self.compile()
     }
@@ -86,59 +82,6 @@ impl AstCompiler {
         CompilerErrorAtLine::raise(error, self.current_line())
     }
 
-    fn collect_functions(&mut self) -> Result<(), CompilerErrorAtLine> {
-        while !self.is_at_end() {
-            if self.match_token(vec![Fn]) {
-                let name_token = self.consume(Identifier, Expected("function name."))?;
-                self.consume(LeftParen, Expected("'(' after function name."))?;
-                let mut parameters = vec![];
-                while !self.check(RightParen) {
-                    if parameters.len() >= 25 {
-                        return Err(self.raise(TooManyParameters));
-                    }
-                    let parm_name = self.consume(Identifier, Expected("a parameter name."))?;
-
-                    self.consume(Colon, Expected(": after parameter name"))?;
-                    let var_type = self.peek().token_type;
-                    self.vars.push(Expression::Variable {
-                        name: parm_name.lexeme.to_string(),
-                        var_type,
-                        line: parm_name.line,
-                    });
-                    self.advance();
-                    parameters.push(Parameter {
-                        name: parm_name,
-                        var_type,
-                    });
-                    if self.peek().token_type == TokenType::Comma {
-                        self.advance();
-                    }
-                }
-                self.consume(RightParen, Expected(" ')' after parameters."))?;
-                let return_type = if self.check(SingleRightArrow) {
-                    self.consume(SingleRightArrow, Expected("->"))?;
-                    self.advance().token_type
-                } else {
-                    TokenType::Void
-                };
-                self.consume(Colon, Expected("colon (:) after function declaration."))?;
-                self.consume(Eol, Expected("end of line."))?;
-
-                let function = Function {
-                    name: name_token.clone(),
-                    parameters,
-                    return_type,
-                    body: vec![],
-                };
-
-                self.functions.insert(name_token.lexeme, function);
-            } else {
-                self.advance();
-            }
-        }
-        Ok(())
-    }
-
     fn indent(&mut self) -> Result<Option<Statement>, CompilerErrorAtLine> {
         let expected_indent = *self.indent.last().unwrap();
         // skip empty lines
@@ -168,11 +111,65 @@ impl AstCompiler {
             self.let_declaration()
         } else if self.match_token(vec![Object]) {
             self.object_declaration()
+        } else if self.match_token(vec![TokenType::Pipe]) {
+            self.guard_declaration()
         } else {
             self.statement()
         }
     }
 
+    //  | /. -> service.get_all()
+    //  | /{uuid} -> service.get(uuid)?
+    //  | ?{query.firstname} -> service.get_by_firstname(fname)?
+    fn guard_declaration(&mut self) -> Result<Statement, CompilerErrorAtLine> {
+        let if_expr = self.guard_if_expr()?;
+        let then_expr = self.expression()?;
+        Ok(Statement::GuardStatement { if_expr, then_expr })
+    }
+
+    fn guard_if_expr(&mut self) -> Result<Expression, CompilerErrorAtLine> {
+        while !self.check(SingleRightArrow) {
+            if self.match_token(vec![Slash]) {
+                return self.path_guard_expr();
+            } else if self.match_token(vec![TokenType::Question]) {
+                return self.query_guard_expr();
+            } else {
+                return Err(self.raise(Expected("-> or ?")));
+            }
+        }
+        Ok(Stop {
+            line: self.peek().line,
+        })
+    }
+
+    fn query_guard_expr(&mut self) -> Result<Expression, CompilerErrorAtLine> {
+        if self.match_token(vec![LeftBrace]) {
+            let query_params = self.expression()?;
+            self.consume(RightBrace, Expected("'}' after guard expression."))?;
+            Ok(query_params)
+        } else {
+            Ok(Stop {
+                line: self.peek().line,
+            })
+        }
+    }
+
+    fn path_guard_expr(&mut self) -> Result<Expression, CompilerErrorAtLine> {
+        if self.match_token(vec![LeftBrace]) {
+            let path_params = self.match_expression()?;
+            self.consume(RightBrace, Expected("'}' after guard expression."))?;
+            Ok(path_params)
+        } else {
+            Ok(Stop {
+                line: self.peek().line,
+            })
+        }
+    }
+
+    fn match_expression(&mut self) -> Result<Expression, CompilerErrorAtLine> {
+        Err(self.raise(Expected("unimplemented")))
+    }
+
     fn object_declaration(&mut self) -> Result<Statement, CompilerErrorAtLine> {
         let type_name = self.consume(Identifier, Expected("object name."))?;
         self.consume(Colon, Expected("':' after object name."))?;
@@ -194,7 +191,7 @@ impl AstCompiler {
             if !done {
                 let field_name = self.consume(Identifier, Expected("an object field name."))?;
                 self.consume(Colon, Expected("':' after field name."))?;
-                let field_type = self.peek().token_type;
+                let field_type = self.peek().token_type.clone();
                 if field_type.is_type() {
                     self.advance();
                 } else {
@@ -216,40 +213,61 @@ impl AstCompiler {
     fn function_declaration(&mut self) -> Result<Statement, CompilerErrorAtLine> {
         let name_token = self.consume(Identifier, Expected("function name."))?;
         self.consume(LeftParen, Expected("'(' after function name."))?;
+        let mut parameters = vec![];
         while !self.check(RightParen) {
-            self.advance();
+            if parameters.len() >= 25 {
-        }
+                return Err(self.raise(TooManyParameters));
+            }
+            let parm_name = self.consume(Identifier, Expected("a parameter name."))?;
+
+            self.consume(Colon, Expected(": after parameter name"))?;
+            let var_type = self.peek().token_type.clone();
 
-        self.consume(RightParen, Expected("')' after parameters."))?;
-        while !self.check(Colon) {
             self.advance();
+            parameters.push(Parameter {
+                name: parm_name,
+                var_type,
+            });
+            if self.peek().token_type == TokenType::Comma {
+                self.advance();
+            }
         }
+        self.consume(RightParen, Expected(" ')' after parameters."))?;
+        let return_type = if self.check(SingleRightArrow) {
+            self.consume(SingleRightArrow, Expected("->"))?;
+            self.advance().token_type.clone()
+        } else {
+            TokenType::Void
+        };
         self.consume(Colon, Expected("colon (:) after function declaration."))?;
         self.consume(Eol, Expected("end of line."))?;
 
         let current_indent = self.indent.last().unwrap();
         self.indent.push(current_indent + 1);
+
         let body = self.compile()?;
 
-        self.functions.get_mut(&name_token.lexeme).unwrap().body = body;
+        let function = Function {
-
+            name: name_token.clone(),
-        let function_stmt = Statement::FunctionStmt {
+            parameters,
-            function: self.functions.get(&name_token.lexeme).unwrap().clone(),
+            return_type,
+            body,
         };
-        Ok(function_stmt)
+
+        Ok(Statement::FunctionStmt { function })
     }
 
     fn let_declaration(&mut self) -> Result<Statement, CompilerErrorAtLine> {
         if self.peek().token_type.is_type() {
             return Err(self.raise(CompilerError::KeywordNotAllowedAsIdentifier(
-                self.peek().token_type,
+                self.peek().token_type.clone(),
             )));
         }
         let name_token = self.consume(Identifier, Expected("variable name."))?;
 
         let declared_type = if self.check(Colon) {
             self.advance();
-            Some(self.advance().token_type)
+            Some(self.advance().token_type.clone())
         } else {
             None
         };
@@ -258,22 +276,22 @@ impl AstCompiler {
             let initializer = self.expression()?;
             self.consume(Eol, Expected("end of line after initializer."))?;
 
-            let inferred_type = initializer.infer_type();
+            // let inferred_type = initializer.infer_type();
-            let var_type = match calculate_type(declared_type, inferred_type) {
+            // let var_type = match calculate_type(declared_type, inferred_type) {
-                Ok(var_type) => var_type,
+            //     Ok(var_type) => var_type,
-                Err(e) => {
+            //     Err(e) => {
-                    self.had_error = true;
+            //         self.had_error = true;
-                    return Err(self.raise(TypeError(Box::new(e))));
+            //         return Err(self.raise(TypeError(Box::new(e))));
-                }
+            //     }
-            };
+            // };
-            self.vars.push(Expression::Variable {
+            // self.vars.push(Variable {
-                name: name_token.lexeme.to_string(),
+            //     name: name_token.lexeme.to_string(),
-                var_type,
+            //     var_type,
-                line: name_token.line,
+            //     line: name_token.line,
-            });
+            // });
             Ok(Statement::VarStmt {
                 name: name_token,
-                var_type,
+                var_type: declared_type.unwrap_or(TokenType::Unknown),
                 initializer,
             })
         } else {
@@ -324,7 +342,7 @@ impl AstCompiler {
 
     fn bit_or(&mut self) -> Result<Expression, CompilerErrorAtLine> {
         let expr = self.bit_xor()?;
-        self.binary(vec![TokenType::BitOr], expr)
+        self.binary(vec![TokenType::Pipe], expr)
     }
 
     fn bit_xor(&mut self) -> Result<Expression, CompilerErrorAtLine> {
@@ -469,9 +487,13 @@ impl AstCompiler {
         } else {
             let token = self.advance().clone();
             debug!("{:?}", token);
+            // function call?
             if self.match_token(vec![LeftParen]) {
                 self.function_call(token.lexeme)?
+            } else if self.match_token(vec![Colon]) {
+                self.named_parameter(&token)?
             } else if self.check(Dot) {
+                // chain of variable or function lookups?
                 let mut name = "/".to_string();
                 name.push_str(&self.previous().lexeme);
                 while self.match_token(vec![Dot]) {
@@ -479,11 +501,13 @@ impl AstCompiler {
                     name.push_str(&self.peek().lexeme);
                     self.advance();
                 }
+                // chained function call?
                 if self.match_token(vec![LeftParen]) {
                     self.function_call(name)?
                 } else {
+                    // empty line
                     return if self.match_token(vec![Eol, Eof]) {
-                        Ok(Literal {
+                        Ok(Expression::Literal {
                             value: Value::Void,
                             literaltype: Object,
                             line: token.line,
@@ -493,11 +517,22 @@ impl AstCompiler {
                     };
                 }
             } else {
+                // none of the above, must be a variable lookup
                 self.variable_lookup(&token)?
             }
         })
     }
 
+    fn named_parameter(&mut self, name: &Token) -> Result<Expression, CompilerErrorAtLine> {
+        let value = self.expression()?;
+        let line = name.line;
+        Ok(NamedParameter {
+            name: name.clone(),
+            value: Box::new(value),
+            line,
+        })
+    }
+
     fn list(&mut self) -> Result<Expression, CompilerErrorAtLine> {
         let mut list = vec![];
         while !self.match_token(vec![RightBracket]) {
@@ -537,92 +572,34 @@ impl AstCompiler {
         })
     }
 
-    fn variable_lookup(&mut self, token: &Token) -> Result<Expression, CompilerErrorAtLine> {
+    fn variable_lookup(&mut self, name: &Token) -> Result<Expression, CompilerErrorAtLine> {
-        if let Some((var_name, var_type)) = self
+        Ok(Variable {
-            .vars
+            name: name.lexeme.to_string(),
-            .iter()
+            var_type: TokenType::Unknown,
-            .filter_map(|e| {
+            line: name.line,
-                if let Variable { name, var_type, .. } = e {
+        })
-                    Some((name, var_type))
-                } else {
-                    None
-                }
-            })
-            .find(|e| e.0 == &token.lexeme)
-        {
-            Ok(Variable {
-                name: var_name.to_string(),
-                var_type: var_type.clone(),
-                line: token.line,
-            })
-        } else {
-            if self.match_token(vec![Dot]) {
-                let right = self.primary()?;
-                self.binary(vec![Dot], right)
-            } else {
-                if self.is_at_end() {
-                    Ok(Literal {
-                        value: Value::Void,
-                        literaltype: Object,
-                        line: token.line,
-                    })
-                } else {
-                    Err(self.raise(UndeclaredVariable(token.lexeme.clone())))
-                }
-            }
-        }
     }
 
     fn function_call(&mut self, name: String) -> Result<Expression, CompilerErrorAtLine> {
-        if let Some(function) = self.functions.get(&name).cloned() {
+        let mut arguments = vec![];
-            let mut arguments = vec![];
+        while !self.match_token(vec![RightParen]) {
-            while !self.match_token(vec![RightParen]) {
+            if arguments.len() >= 25 {
-                if arguments.len() >= 25 {
+                return Err(self.raise(TooManyParameters));
-                    return Err(self.raise(TooManyParameters));
-                }
-                let arg = self.expression()?;
-                let arg_type = arg.infer_type();
-                if arg_type != function.parameters[arguments.len()].var_type {
-                    return Err(self.raise(IncompatibleTypes(
-                        function.parameters[arguments.len()].var_type,
-                        arg_type,
-                    )));
-                }
-                arguments.push(arg);
-                if self.peek().token_type == TokenType::Comma {
-                    self.advance();
-                } else {
-                    self.consume(RightParen, Expected("')' after arguments."))?;
-                    break;
-                }
             }
-            Ok(FunctionCall {
+            let arg = self.expression()?;
-                line: self.peek().line,
+            arguments.push(arg);
-                name,
+            if self.peek().token_type == TokenType::Comma {
-                arguments,
+                self.advance();
-                return_type: function.return_type,
+            } else {
-            })
+                self.consume(RightParen, Expected("')' after arguments."))?;
-        } else {
+                break;
-            let mut arguments = vec![];
-            while !self.match_token(vec![RightParen]) {
-                if arguments.len() >= 25 {
-                    return Err(self.raise(TooManyParameters));
-                }
-                let arg = self.expression()?;
-                arguments.push(arg);
-                if self.peek().token_type == TokenType::Comma {
-                    self.advance();
-                } else {
-                    self.consume(RightParen, Expected("')' after arguments."))?;
-                    break;
-                }
             }
-            Ok(RemoteFunctionCall {
-                line: self.peek().line,
-                name,
-                arguments,
-            })
         }
+        Ok(FunctionCall {
+            line: self.peek().line,
+            name,
+            arguments,
+        })
     }
 
     fn consume(
@@ -681,45 +658,6 @@ impl AstCompiler {
     }
 }
 
-fn calculate_type(
-    declared_type: Option<TokenType>,
-    inferred_type: TokenType,
-) -> Result<TokenType, CompilerError> {
-    Ok(if let Some(declared_type) = declared_type {
-        if declared_type != inferred_type {
-            match (declared_type, inferred_type) {
-                (I32, I64) => I32, //need this?
-                (I32, Integer) => I32,
-                (U32, I64) => U32,
-                (U32, Integer) => U32,
-                (F32, F64) => F32,
-                (F32, FloatingPoint) => F32,
-                (F64, I64) => F64,
-                (F64, FloatingPoint) => F64,
-                (U64, I64) => U64,
-                (U64, I32) => U64,
-                (StringType, _) => StringType, // meh, this all needs rigorous testing. Update: this is in progress
-                _ => {
-                    return Err(IncompatibleTypes(declared_type, inferred_type));
-                }
-            }
-        } else {
-            declared_type
-        }
-    } else {
-        match inferred_type {
-            Integer | I64 => I64,
-            FloatingPoint => F64,
-            Bool => Bool,
-            Date => Date,
-            ListType => ListType,
-            MapType => MapType,
-            Object => Object,
-            _ => return Err(CompilerError::UnexpectedType(inferred_type)),
-        }
-    })
-}
-
 #[derive(Debug, Clone)]
 pub enum Statement {
     ExpressionStmt {
@@ -740,6 +678,10 @@ pub enum Statement {
         name: Token,
         fields: Vec<Parameter>,
     },
+    GuardStatement {
+        if_expr: Expression,
+        then_expr: Expression,
+    },
 }
 
 impl Statement {
@@ -750,6 +692,7 @@ impl Statement {
             Statement::PrintStmt { value } => value.line(),
             Statement::FunctionStmt { function, .. } => function.name.line,
             Statement::ObjectStmt { name, .. } => name.line,
+            Statement::GuardStatement { if_expr, .. } => if_expr.line(),
         }
     }
 }
@@ -801,13 +744,18 @@ pub enum Expression {
         line: usize,
         name: String,
         arguments: Vec<Expression>,
-        return_type: TokenType,
     },
-    // a remote function call is a function call that is not defined in the current scope
+    Stop {
-    RemoteFunctionCall {
         line: usize,
-        name: String,
+    },
-        arguments: Vec<Expression>,
+    PathMatch {
+        line: usize,
+        condition: Box<Expression>,
+    },
+    NamedParameter {
+        line: usize,
+        name: Token,
+        value: Box<Expression>,
     },
 }
 
@@ -822,85 +770,9 @@ impl Expression {
             Self::Map { line, .. } => *line,
             Variable { line, .. } => *line,
             FunctionCall { line, .. } => *line,
-            RemoteFunctionCall { line, .. } => *line,
+            Stop { line } => *line,
-        }
+            Expression::PathMatch { line, .. } => *line,
-    }
+            NamedParameter { line, .. } => *line,
-
-    pub fn infer_type(&self) -> TokenType {
-        match self {
-            Self::Binary {
-                left,
-                operator,
-                right,
-                ..
-            } => {
-                let left_type = left.infer_type();
-                let right_type = right.infer_type();
-                if vec![Greater, Less, GreaterEqual, LessEqual].contains(&operator.token_type) {
-                    Bool
-                } else if left_type == right_type {
-                    // map to determined numeric type if yet undetermined (32 or 64 bits)
-                    match left_type {
-                        FloatingPoint => F64,
-                        Integer => I64,
-                        _ => left_type,
-                    }
-                } else {
-                    if let Plus = operator.token_type {
-                        // includes string concatenation with numbers
-                        // followed by type coercion to 64 bits for numeric types
-                        debug!("coerce {} : {}", left_type, right_type);
-                        match (left_type, right_type) {
-                            (_, StringType) => StringType,
-                            (StringType, _) => StringType,
-                            (FloatingPoint, _) => F64,
-                            (Integer, FloatingPoint) => F64,
-                            (Integer, _) => I64,
-                            (I64, Integer) => I64,
-                            (F64, _) => F64,
-                            (U64, U32) => U64,
-                            (I64, I32) => I64,
-                            // could add a date and a duration. future work
-                            // could add a List and a value. also future work
-                            // could add a Map and a tuple. Will I add tuple types? Future work!
-                            _ => panic!("Unexpected coercion"),
-                        }
-                        // could have done some fall through here, but this will fail less gracefully,
-                        // so if my thinking is wrong or incomplete it will panic
-                    } else {
-                        // type coercion to 64 bits for numeric types
-                        debug!("coerce {} : {}", left_type, right_type);
-                        match (left_type, right_type) {
-                            (FloatingPoint, _) => F64,
-                            (Integer, FloatingPoint) => F64,
-                            (Integer, I64) => I64,
-                            (I64, FloatingPoint) => F64,
-                            (F64, _) => F64,
-                            (U64, U32) => U64,
-                            (I64, I32) => I64,
-                            (I64, Integer) => I64,
-                            _ => panic!("Unexpected coercion"),
-                        }
-                    }
-                }
-            }
-            Self::Grouping { expression, .. } => expression.infer_type(),
-            Self::Literal { literaltype, .. } => literaltype.clone(),
-            Self::List { literaltype, .. } => literaltype.clone(),
-            Self::Map { literaltype, .. } => literaltype.clone(),
-            Self::Unary {
-                right, operator, ..
-            } => {
-                let literal_type = right.infer_type();
-                if literal_type == Integer && operator.token_type == Minus {
-                    SignedInteger
-                } else {
-                    UnsignedInteger
-                }
-            }
-            Variable { var_type, .. } => var_type.clone(),
-            FunctionCall { return_type, .. } => return_type.clone(),
-            RemoteFunctionCall { .. } => TokenType::Unknown,
         }
     }
 }

src/bytecode_compiler.rs

@@ -1,6 +1,8 @@
-use crate::ast_compiler::{Expression, Function, Statement};
+use crate::ast_compiler::Expression::NamedParameter;
+use crate::ast_compiler::{Expression, Function, Parameter, Statement};
 use crate::chunk::Chunk;
-use crate::errors::CompilerErrorAtLine;
+use crate::errors::{CompilerError, CompilerErrorAtLine, RuntimeError};
+use crate::symbol_builder::{Symbol, calculate_type, infer_type};
 use crate::tokens::TokenType;
 use crate::value::Value;
 use crate::vm::{
@@ -9,17 +11,20 @@ use crate::vm::{
     OP_MULTIPLY, OP_NEGATE, OP_NOT, OP_OR, OP_PRINT, OP_RETURN, OP_SHL, OP_SHR, OP_SUBTRACT,
 };
 use std::collections::HashMap;
+use crate::tokens::TokenType::Unknown;
 
 pub fn compile(
     qualified_name: Option<&str>,
     ast: &Vec<Statement>,
+    symbols: &HashMap<String, Symbol>,
     registry: &mut HashMap<String, Chunk>,
 ) -> Result<(), CompilerErrorAtLine> {
-    compile_in_namespace(ast, qualified_name, registry)
+    compile_in_namespace(ast, qualified_name, symbols, registry)
 }
 
 pub(crate) fn compile_function(
     function: &Function,
+    symbols: &HashMap<String, Symbol>,
     registry: &mut HashMap<String, Chunk>,
     namespace: &str,
 ) -> Result<Chunk, CompilerErrorAtLine> {
@@ -31,18 +36,20 @@ pub(crate) fn compile_function(
 
         compiler.vars.insert(name, var_index);
     }
-
+    let mut chunk = compiler.compile(&function.body, symbols, registry, namespace)?;
-    Ok(compiler.compile(&function.body, registry, namespace)?)
+    chunk.function_parameters = function.parameters.to_vec();
+    Ok(chunk)
 }
 
 pub(crate) fn compile_in_namespace(
     ast: &Vec<Statement>,
     namespace: Option<&str>,
+    symbols: &HashMap<String, Symbol>,
     registry: &mut HashMap<String, Chunk>,
 ) -> Result<(), CompilerErrorAtLine> {
     let name = namespace.unwrap_or("main");
     let compiler = Compiler::new(name);
-    let chunk = compiler.compile(ast, registry, name)?;
+    let chunk = compiler.compile(ast, symbols, registry, name)?;
     let qname = if let Some(namespace) = namespace {
         format!("{}/{}", namespace, "main")
     } else {
@@ -72,11 +79,12 @@ impl Compiler {
     fn compile(
         mut self,
         ast: &Vec<Statement>,
+        symbols: &HashMap<String, Symbol>,
         registry: &mut HashMap<String, Chunk>,
         namespace: &str,
     ) -> Result<Chunk, CompilerErrorAtLine> {
         for statement in ast {
-            self.compile_statement(statement, registry, namespace)?;
+            self.compile_statement(statement, symbols, registry, namespace)?;
         }
 
         self.emit_byte(OP_RETURN);
@@ -86,6 +94,7 @@ impl Compiler {
     fn compile_statement(
         &mut self,
         statement: &Statement,
+        symbols: &HashMap<String, Symbol>,
         registry: &mut HashMap<String, Chunk>,
         namespace: &str,
     ) -> Result<(), CompilerErrorAtLine> {
@@ -96,21 +105,44 @@ impl Compiler {
                 var_type,
                 initializer,
             } => {
-                let name_index = self.chunk.add_var(var_type, &name.lexeme);
+                let name = name.lexeme.as_str();
-                self.vars.insert(name.lexeme.clone(), name_index);
+                let var = symbols.get(name);
-                self.compile_expression(namespace, initializer, registry)?;
+                if let Some(Symbol::Variable {
-                self.emit_bytes(OP_ASSIGN, name_index as u16);
+                    var_type,
+                    initializer,
+                    ..
+                }) = var
+                {
+                    let inferred_type = infer_type(initializer, symbols);
+                    let calculated_type = calculate_type(var_type, &inferred_type, symbols)
+                        .map_err(|e| CompilerErrorAtLine::raise(e, statement.line()))?;
+                    if var_type != &Unknown && var_type != &calculated_type {
+                        return Err(CompilerErrorAtLine::raise(
+                            CompilerError::IncompatibleTypes(var_type.clone(), calculated_type),
+                            statement.line(),
+                        ));
+                    }
+                    let name_index = self.chunk.add_var(var_type, name);
+                    self.vars.insert(name.to_string(), name_index);
+                    self.compile_expression(namespace, initializer, symbols, registry)?;
+                    self.emit_bytes(OP_ASSIGN, name_index as u16);
+                } else {
+                    return Err(CompilerErrorAtLine::raise(
+                        CompilerError::UndeclaredVariable(name.to_string()),
+                        statement.line(),
+                    ));
+                }
             }
             Statement::PrintStmt { value } => {
-                self.compile_expression(namespace, value, registry)?;
+                self.compile_expression(namespace, value, symbols, registry)?;
                 self.emit_byte(OP_PRINT);
             }
             Statement::ExpressionStmt { expression } => {
-                self.compile_expression(namespace, expression, registry)?;
+                self.compile_expression(namespace, expression, symbols, registry)?;
             }
             Statement::FunctionStmt { function } => {
                 let function_name = function.name.lexeme.clone();
-                let compiled_function = compile_function(function, registry, namespace)?;
+                let compiled_function = compile_function(function, symbols, registry, namespace)?;
                 registry.insert(
                     format!("{}/{}", self.chunk.name, function_name),
                     compiled_function,
@@ -119,6 +151,9 @@ impl Compiler {
             Statement::ObjectStmt { name, fields } => {
                 self.chunk.add_object_def(&name.lexeme, fields);
             }
+            Statement::GuardStatement { .. } => {
+                unimplemented!("guard statement")
+            }
         }
         Ok(())
     }
@@ -127,37 +162,63 @@ impl Compiler {
         &mut self,
         namespace: &str,
         expression: &Expression,
+        symbols: &HashMap<String, Symbol>,
         registry: &mut HashMap<String, Chunk>,
     ) -> Result<(), CompilerErrorAtLine> {
         match expression {
+            // Expression::FunctionCall {
+            //     name, arguments, ..
+            // } => {
+            //     let qname = format!("{}.{}", namespace, name);
+            //     let name_index = self
+            //         .chunk
+            //         .find_constant(&qname)
+            //         .unwrap_or_else(|| self.chunk.add_constant(Value::String(qname)));
+            //
+            //     for argument in arguments {
+            //         self.compile_expression(namespace, argument, registry)?;
+            //     }
+            //     self.emit_bytes(OP_CALL, name_index as u16);
+            //     self.emit_byte(arguments.len() as u16);
+            // }
             Expression::FunctionCall {
                 name, arguments, ..
-            } => {
-                let qname = format!("{}.{}", namespace, name);
-                let name_index = self
-                    .chunk
-                    .find_constant(&qname)
-                    .unwrap_or_else(|| self.chunk.add_constant(Value::String(qname)));
-
-                for argument in arguments {
-                    self.compile_expression(namespace, argument, registry)?;
-                }
-                self.emit_bytes(OP_CALL, name_index as u16);
-                self.emit_byte(arguments.len() as u16);
-            }
-            Expression::RemoteFunctionCall {
-                name, arguments, ..
             } => {
                 let name_index = self
                     .chunk
                     .find_constant(&name)
                     .unwrap_or_else(|| self.chunk.add_constant(Value::String(name.to_string())));
-
+                let function = symbols.get(name);
-                for argument in arguments {
+                if let Some(Symbol::Function {
-                    self.compile_expression(namespace, argument, registry)?;
+                    name,
+                    parameters,
+                    return_type,
+                    body,
+                }) = function
+                {
+                    for parameter in parameters {
+                        for argument in arguments {
+                            if let NamedParameter { name, .. } = argument {
+                                if name.lexeme == parameter.name.lexeme {
+                                    self.compile_expression(
+                                        namespace, argument, symbols, registry,
+                                    )?;
+                                    break;
+                                }
+                            } else {
+                                self.compile_expression(namespace, argument, symbols, registry)?;
+                                break;
+                            }
+                        }
+                    }
+                    self.emit_bytes(OP_CALL, name_index as u16);
+                    self.emit_byte(arguments.len() as u16);
+                } else {
+                    return Err(CompilerErrorAtLine::raise(
+                        CompilerError::FunctionNotFound(name.to_string()),
+                        0,
+                    ));
                 }
-                self.emit_bytes(OP_CALL, name_index as u16);
-                self.emit_byte(arguments.len() as u16);
             }
             Expression::Variable { name, .. } => {
                 let name_index = self.vars.get(name).unwrap();
@@ -168,24 +229,24 @@ impl Compiler {
             }
             Expression::List { values, .. } => {
                 for expr in values {
-                    self.compile_expression(namespace, expr, registry)?;
+                    self.compile_expression(namespace, expr, symbols, registry)?;
                 }
                 self.emit_bytes(OP_DEF_LIST, values.len() as u16);
             }
             Expression::Map { entries, .. } => {
                 for (key, value) in entries {
-                    self.compile_expression(namespace, key, registry)?;
+                    self.compile_expression(namespace, key, symbols, registry)?;
-                    self.compile_expression(namespace, value, registry)?;
+                    self.compile_expression(namespace, value, symbols, registry)?;
                 }
                 self.emit_bytes(OP_DEF_MAP, entries.len() as u16);
             }
             Expression::Grouping { expression, .. } => {
-                self.compile_expression(namespace, expression, registry)?
+                self.compile_expression(namespace, expression, symbols, registry)?
             }
             Expression::Unary {
                 operator, right, ..
             } => {
-                self.compile_expression(namespace, right, registry)?;
+                self.compile_expression(namespace, right, symbols, registry)?;
                 match operator.token_type {
                     TokenType::Minus => {
                         self.emit_byte(OP_NEGATE);
@@ -202,15 +263,15 @@ impl Compiler {
                 right,
                 ..
             } => {
-                self.compile_expression(namespace, left, registry)?;
+                self.compile_expression(namespace, left, symbols, registry)?;
-                self.compile_expression(namespace, right, registry)?;
+                self.compile_expression(namespace, right, symbols, registry)?;
                 match operator.token_type {
                     TokenType::Plus => self.emit_byte(OP_ADD),
                     TokenType::Minus => self.emit_byte(OP_SUBTRACT),
                     TokenType::Star => self.emit_byte(OP_MULTIPLY),
                     TokenType::Slash => self.emit_byte(OP_DIVIDE),
                     TokenType::BitAnd => self.emit_byte(OP_BITAND),
-                    TokenType::BitOr => self.emit_byte(OP_BITOR),
+                    TokenType::Pipe => self.emit_byte(OP_BITOR),
                     TokenType::BitXor => self.emit_byte(OP_BITXOR),
                     TokenType::GreaterGreater => self.emit_byte(OP_SHR),
                     TokenType::LessLess => self.emit_byte(OP_SHL),
@@ -224,6 +285,9 @@ impl Compiler {
                     _ => unimplemented!("binary other than plus, minus, star, slash"),
                 }
             }
+            Expression::Stop { line } => {}
+            Expression::PathMatch { line, .. } => {}
+            Expression::NamedParameter { line, .. } => {}
         }
         Ok(())
     }

src/chunk.rs

@@ -16,6 +16,7 @@ pub struct Chunk {
     pub constants: Vec<Value>,
     lines: Vec<usize>,
     object_defs: HashMap<String, Vec<Parameter>>,
+    pub(crate) function_parameters: Vec<Parameter>,
     pub vars: Vec<(TokenType, String)>
 }
 
@@ -40,6 +41,7 @@ impl Chunk {
             constants: vec![],
             lines: vec![],
             object_defs: HashMap::new(),
+            function_parameters: vec![],
             vars: vec![]
         }
     }

src/compiler_tests.rs

@@ -25,19 +25,31 @@ mod tests {
 
     #[test]
     fn literal_list() {
-        assert_eq!(run(r#"["abc","def"]"#), Ok(Value::List(vec![Value::String("abc".into()), Value::String("def".into())])));
+        assert_eq!(
+            run(r#"["abc","def"]"#),
+            Ok(Value::List(vec![
+                Value::String("abc".into()),
+                Value::String("def".into())
+            ]))
+        );
     }
 
     #[test]
     fn infer_type() {
-        assert_eq!(run(r#"let a=1
+        assert_eq!(
-a"#), Ok(Value::I64(1)));
+            run(r#"let a=1
+a"#),
+            Ok(Value::I64(1))
+        );
     }
 
     #[test]
     fn define_u32() {
-        assert_eq!(run(r#"let a:u32=1
+        assert_eq!(
-a"#), Ok(Value::U32(1)));
+            run(r#"let a:u32=1
+a"#),
+            Ok(Value::U32(1))
+        );
     }
 
     #[test]
@@ -56,7 +68,7 @@ a"#),
         if let Err(e) = &r {
             assert_eq!(
                 e.to_string(),
-                "Compilation failed: error at line 1, Type mismatch: Expected u32, found i32/64"
+                "Compilation failed: error at line 1, Expected u32, found i32/64"
             );
         }
     }
@@ -68,7 +80,7 @@ a"#),
         if let Err(e) = &r {
             assert_eq!(
                 e.to_string(),
-                "Compilation failed: error at line 1, Type mismatch: Expected u64, found i32/64"
+                "Compilation failed: error at line 1, Expected u64, found i32/64"
             );
         }
     }
@@ -80,7 +92,7 @@ a"#),
         if let Err(e) = &r {
             assert_eq!(
                 e.to_string(),
-                "Compilation failed: error at line 1, Type mismatch: Expected u64, found string"
+                "Compilation failed: error at line 1, Expected u64, found string"
             );
         }
     }
@@ -106,18 +118,20 @@ object Person:
         assert!(r.is_ok()); // does nothing runtime
     }
 
-    //     #[test]
+//     #[test]
-    //     fn object_() {
+//     fn object_() {
-    //         let r = compile(r#"
+//         let r = run(
-    // object Person:
+//             r#"
-    //    name: string
+// object Person:
-    //
+//    name: string
-    // let p = Person{name: "Sander"}
+//
-    // print p
+// let p = Person(name: "Sander")
-    // "#, );
+// print p
-    //         println!("{:?}", r);
+// "#,
-    //         assert!(r.is_ok());
+//         );
-    //     }
+//         println!("{:?}", r);
+//         assert!(r.is_ok());
+//     }
 
     #[test]
     fn literal_map() {
@@ -151,39 +165,54 @@ m"#);
     }
 
     #[test]
-    fn keyword_error(){
+    fn keyword_error() {
         let result = run(r#"let map = {"name": "Dent"}"#);
         assert!(result.is_err());
-        assert_eq!("Compilation failed: error at line 1, 'map' is a keyword. You cannot use it as an identifier",result.unwrap_err().to_string());
+        assert_eq!(
+            "Compilation failed: error at line 1, 'map' is a keyword. You cannot use it as an identifier",
+            result.unwrap_err().to_string()
+        );
     }
 
     #[test]
-    fn add_strings(){
+    fn add_strings() {
         assert_eq!(run(r#""a"+"b""#), Ok(Value::String("ab".into())));
     }
 
     #[test]
-    fn add_string_and_int(){
+    fn add_string_and_int() {
         assert_eq!(run(r#""a"+42"#), Ok(Value::String("a42".into())));
     }
 
     #[test]
-    fn add_string_and_bool(){
+    fn add_string_and_bool() {
         assert_eq!(run(r#""a"+false"#), Ok(Value::String("afalse".into())));
     }
 
     #[test]
-    fn add_string_and_scientific_float(){
+    fn add_string_and_scientific_float() {
-        assert_eq!(run(r#""a"+4.2e10"#), Ok(Value::String("a42000000000".into())));
+        assert_eq!(
+            run(r#""a"+4.2e10"#),
+            Ok(Value::String("a42000000000".into()))
+        );
     }
 
     #[test]
-    fn add_hex_ints(){
+    fn add_hex_ints() {
         assert_eq!(run(r#"0x10 + 0x20"#), Ok(Value::U32(48)));
     }
 
-    #[test]
+    // #[test]
-    fn package(){
+    // fn package() {
-        assert_eq!(run(r#"a.b.c()"#), Ok(Value::U32(48)));
+    //     assert_eq!(run(r#"a.b.c()"#), Ok(Value::U32(48)));
-    }
+    // }
+
+    // #[test]
+    // fn guards() {
+    //     assert_eq!(
+    //         run(r#"fn get_all_users() -> list:
+    // | /{uuid} -> service.get_by_uuid(uuid)?"#),
+    //         Ok(Value::Void)
+    //     );
+    // }
 }

src/lib.rs

@@ -19,6 +19,7 @@ pub mod file_watch;
 mod keywords;
 pub mod repl;
 pub mod scanner;
+mod symbol_builder;
 mod tokens;
 mod value;
 pub mod vm;
@@ -34,9 +35,12 @@ pub fn compile_sourcedir(source_dir: &str) -> Result<HashMap<String, Chunk>, Cru
             let tokens = scan(&source)?;
             match ast_compiler::compile(Some(&path), tokens) {
                 Ok(statements) => {
-                    println!("{}", path);
                     let path = path.strip_prefix(source_dir).unwrap().replace(".crud", "");
-                    bytecode_compiler::compile(Some(&path), &statements, &mut registry)?;
+
+                    let mut symbol_table = HashMap::new();
+                    symbol_builder::build(&path, &statements, &mut symbol_table);
+
+                    bytecode_compiler::compile(Some(&path), &statements, &symbol_table, &mut registry)?;
                 }
                 Err(e) => {
                     println!("{}", e);
@@ -56,7 +60,9 @@ pub fn map_underlying() -> fn(std::io::Error) -> CrudLangError {
 pub fn recompile(src: &str, registry: &mut HashMap<String, Chunk>) -> Result<(), CrudLangError> {
     let tokens = scan(src)?;
     let ast = ast_compiler::compile(None, tokens)?;
-    bytecode_compiler::compile(None, &ast, registry)?;
+    let mut symbol_table = HashMap::new();
+    symbol_builder::build("", &ast, &mut symbol_table);
+    bytecode_compiler::compile(None, &ast, &symbol_table, registry)?;
     Ok(())
 }
 
@@ -64,15 +70,19 @@ pub fn compile(src: &str) -> Result<HashMap<String, Chunk>, CrudLangError> {
     let tokens = scan(src)?;
     let mut registry = HashMap::new();
     let ast = ast_compiler::compile(None, tokens)?;
-    bytecode_compiler::compile(None, &ast, &mut registry)?;
+    let mut symbol_table = HashMap::new();
+    symbol_builder::build("", &ast, &mut symbol_table);
+    bytecode_compiler::compile(None, &ast, &symbol_table, &mut registry)?;
     Ok(registry)
 }
 
-fn run(src: &str) -> Result<Value, CrudLangError> {
+pub(crate) fn run(src: &str) -> Result<Value, CrudLangError> {
     let tokens = scan(src)?;
-    let mut registry = HashMap::new();
     let ast = ast_compiler::compile(None, tokens)?;
-    bytecode_compiler::compile(None, &ast, &mut registry)?;
+    let mut symbol_table = HashMap::new();
+    symbol_builder::build("", &ast, &mut symbol_table);
+    let mut registry = HashMap::new();
+    bytecode_compiler::compile(None, &ast, &symbol_table, &mut registry)?;
     let registry = ArcSwap::from(Arc::new(registry));
     interpret(registry.load(), "main").map_err(CrudLangError::from)
 }

src/scanner.rs

@@ -1,6 +1,6 @@
 use crate::errors::CompilerError::{IllegalCharLength, UnexpectedIdentifier, Unterminated};
 use crate::errors::{CompilerError, CompilerErrorAtLine};
-use crate::tokens::TokenType::{BitXor, FloatingPoint, Integer, U32, U64};
+use crate::tokens::TokenType::{BitXor, FloatingPoint, Integer, Question, U32, U64};
 use crate::{
     keywords,
     tokens::{
@@ -129,11 +129,12 @@ impl Scanner {
                     let t = if self.match_next('|') {
                         TokenType::LogicalOr
                     } else {
-                        TokenType::BitOr
+                        TokenType::Pipe
                     };
                     self.add_token(t);
                 }
                 '^' => self.add_token(BitXor),
+                '?' => self.add_token(Question),
                 _ => {
                     if c == '0' && self.peek() == 'x' {
                         self.hex_number()?;

src/symbol_builder.rs

@@ -0,0 +1,235 @@
+use crate::ast_compiler::{Expression, Parameter, Statement};
+use crate::errors::CompilerError;
+use crate::errors::CompilerError::{IncompatibleTypes, TypeError};
+use crate::tokens::{Token, TokenType};
+use crate::tokens::TokenType::{
+    Bool, Date, F32, F64, FloatingPoint, Greater, GreaterEqual, I32, I64, Integer, Less, LessEqual,
+    ListType, MapType, Minus, Object, Plus, SignedInteger, StringType, U32, U64, Unknown,
+    UnsignedInteger,
+};
+use log::debug;
+use std::collections::HashMap;
+
+pub enum Symbol {
+    Function {
+        name: String,
+        parameters: Vec<Parameter>,
+        return_type: TokenType,
+        body: Vec<Statement>,
+    },
+    Variable {
+        name: String,
+        var_type: TokenType,
+        initializer: Expression,
+    },
+    Object {
+        name: String,
+        fields: Vec<Parameter>,
+    },
+}
+
+fn make_qname(path: &str, name: &Token) -> String {
+    if path == "" {
+        name.lexeme.to_string()
+    } else {
+        format!("{}.{}", path, name.lexeme)
+    }
+}
+
+pub fn build(path: &str, ast: &[Statement], symbols: &mut HashMap<String, Symbol>) {
+    for statement in ast {
+        match statement {
+            Statement::VarStmt {
+                name,
+                var_type,
+                initializer,
+            } => {
+
+                symbols.insert(
+                    make_qname(path, name),
+                    Symbol::Variable {
+                        name: name.lexeme.to_string(),
+                        var_type: var_type.clone(),
+                        initializer: initializer.clone(),
+                    },
+                );
+            }
+            Statement::FunctionStmt { function } => {
+                symbols.insert(
+                    make_qname(path, &function.name),
+                    Symbol::Function {
+                        name: function.name.lexeme.to_string(),
+                        parameters: function.parameters.to_vec(),
+                        return_type: function.return_type.clone(),
+                        body: function.body.to_vec(),
+                    },
+                );
+            }
+            Statement::ObjectStmt { name, fields } => {
+                symbols.insert(
+                    make_qname(path, name),
+                    Symbol::Object {
+                        name: name.lexeme.to_string(),
+                        fields: fields.to_vec(),
+                    },
+                );
+            }
+            _ => {}
+        }
+    }
+}
+
+pub fn add_types(
+    path: &str,
+    ast: &[Statement],
+    symbols: &mut HashMap<String, Symbol>,
+) -> Result<(), CompilerError> {
+    for statement in ast {
+        match statement {
+            Statement::VarStmt {
+                name,
+                var_type,
+                initializer,
+            } => {
+                let inferred_type = infer_type(initializer, symbols);
+                let calculated_type = calculate_type(var_type, &inferred_type, symbols)?;
+                let entry = symbols.get_mut(&format!("{}.{}", path, name.lexeme));
+                if let Some(Symbol::Variable { var_type, .. }) = entry {
+                    *var_type = calculated_type;
+                }
+            }
+            _ => {}
+        }
+    }
+    Ok(())
+}
+
+pub fn calculate_type(
+    declared_type: &TokenType,
+    inferred_type: &TokenType,
+    _symbols: &HashMap<String, Symbol>,
+) -> Result<TokenType, CompilerError> {
+    Ok(if declared_type != &Unknown {
+        if declared_type != inferred_type {
+            match (declared_type, inferred_type) {
+                (I32, I64) => I32, //need this?
+                (I32, Integer) => I32,
+                (U32, I64) => U32,
+                (U32, Integer) => U32,
+                (F32, F64) => F32,
+                (F32, FloatingPoint) => F32,
+                (F64, I64) => F64,
+                (F64, FloatingPoint) => F64,
+                (U64, I64) => U64,
+                (U64, I32) => U64,
+                (StringType, _) => StringType, // meh, this all needs rigorous testing. Update: this is in progress
+                _ => {
+                    return Err(IncompatibleTypes(
+                        declared_type.clone(),
+                        inferred_type.clone(),
+                    ));
+                }
+            }
+        } else {
+            declared_type.clone()
+        }
+    } else {
+        match inferred_type {
+            Integer | I64 => I64,
+            FloatingPoint => F64,
+            Bool => Bool,
+            Date => Date,
+            ListType => ListType,
+            MapType => MapType,
+            Object => Object,
+            _ => return Err(CompilerError::UnexpectedType(inferred_type.clone())),
+        }
+    })
+}
+
+pub fn infer_type(expr: &Expression, symbols: &HashMap<String, Symbol>) -> TokenType {
+    match expr {
+        Expression::Binary {
+            left,
+            operator,
+            right,
+            ..
+        } => {
+            let left_type = infer_type(left, symbols);
+            let right_type = infer_type(right, symbols);
+            if vec![Greater, Less, GreaterEqual, LessEqual].contains(&operator.token_type) {
+                Bool
+            } else if left_type == right_type {
+                // map to determined numeric type if yet undetermined (32 or 64 bits)
+                match left_type {
+                    FloatingPoint => F64,
+                    Integer => I64,
+                    _ => left_type,
+                }
+            } else {
+                if let Plus = operator.token_type {
+                    // includes string concatenation with numbers
+                    // followed by type coercion to 64 bits for numeric types
+                    debug!("coerce {} : {}", left_type, right_type);
+                    match (left_type, right_type) {
+                        (_, StringType) => StringType,
+                        (StringType, _) => StringType,
+                        (FloatingPoint, _) => F64,
+                        (Integer, FloatingPoint) => F64,
+                        (Integer, _) => I64,
+                        (I64, Integer) => I64,
+                        (F64, _) => F64,
+                        (U64, U32) => U64,
+                        (I64, I32) => I64,
+                        // could add a date and a duration. future work
+                        // could add a List and a value. also future work
+                        // could add a Map and a tuple. Will I add tuple types? Future work!
+                        _ => panic!("Unexpected coercion"),
+                    }
+                    // could have done some fall through here, but this will fail less gracefully,
+                    // so if my thinking is wrong or incomplete it will panic
+                } else {
+                    // type coercion to 64 bits for numeric types
+                    debug!("coerce {} : {}", left_type, right_type);
+                    match (left_type, right_type) {
+                        (FloatingPoint, _) => F64,
+                        (Integer, FloatingPoint) => F64,
+                        (Integer, I64) => I64,
+                        (I64, FloatingPoint) => F64,
+                        (F64, _) => F64,
+                        (U64, U32) => U64,
+                        (I64, I32) => I64,
+                        (I64, Integer) => I64,
+                        _ => panic!("Unexpected coercion"),
+                    }
+                }
+            }
+        }
+        Expression::Grouping { expression, .. } => infer_type(expression, symbols),
+        Expression::Literal { literaltype, .. } => literaltype.clone(),
+        Expression::List { literaltype, .. } => literaltype.clone(),
+        Expression::Map { literaltype, .. } => literaltype.clone(),
+        Expression::Unary {
+            right, operator, ..
+        } => {
+            let literal_type = infer_type(right, symbols);
+            if literal_type == Integer && operator.token_type == Minus {
+                SignedInteger
+            } else {
+                UnsignedInteger
+            }
+        }
+        Expression::Variable { var_type, .. } => var_type.clone(),
+        Expression::FunctionCall { name, .. } => {
+            let symbol = symbols.get(name);
+            if let Some(Symbol::Function { return_type, .. }) = symbol {
+                return_type.clone()
+            } else {
+                Unknown
+            }
+        }
+        Expression::Stop { .. } => TokenType::Unknown,
+        Expression::PathMatch { .. } => TokenType::Unknown,
+        Expression::NamedParameter { .. } => TokenType::Unknown,
+    }
+}

src/tokens.rs

@@ -17,12 +17,12 @@ impl Token {
     }
 }
 
-#[derive(Debug, PartialEq, Clone, Copy, Hash)]
+#[derive(Debug, PartialEq, Clone, Hash)]
 pub enum TokenType {
     Bang,
     BangEqual,
     BitAnd,
-    BitOr,
+    Pipe,
     BitXor,
     Bool,
     Char,
@@ -71,6 +71,7 @@ pub enum TokenType {
     Object,
     Plus,
     Print,
+    Question,
     Return,
     RightParen,
     RightBrace,
@@ -86,6 +87,7 @@ pub enum TokenType {
     Unknown,
     Void,
     While,
+    ObjectType(String)
 }
 
 impl fmt::Display for TokenType {
@@ -104,7 +106,7 @@ impl fmt::Display for TokenType {
             TokenType::Bang => write!(f, "!"),
             TokenType::BangEqual => write!(f, "!="),
             TokenType::BitAnd => write!(f, "&"),
-            TokenType::BitOr => write!(f, "|"),
+            TokenType::Pipe => write!(f, "|"),
             TokenType::BitXor => write!(f, "^"),
             TokenType::Colon => write!(f, ":"),
             TokenType::Comma => write!(f, ","),
@@ -142,8 +144,10 @@ impl fmt::Display for TokenType {
             TokenType::Minus => write!(f, "-"),
             TokenType::Not => write!(f, "not"),
             TokenType::Object => write!(f, "object"),
+            TokenType::ObjectType(_) => write!(f, "object"),
             TokenType::Plus => write!(f, "+"),
             TokenType::Print => write!(f, "print"),
+            TokenType::Question => write!(f, "?"),
             TokenType::Return => write!(f, "return"),
             TokenType::RightParen => write!(f, ")"),
             TokenType::RightBrace => write!(f, "}}"),
@@ -158,6 +162,7 @@ impl fmt::Display for TokenType {
             TokenType::While => write!(f, "while"),
             TokenType::SignedInteger => write!(f, "i32/64"),
             TokenType::UnsignedInteger => write!(f, "u32/64"),
+
         }
     }
 }

src/vm.rs

@@ -203,7 +203,7 @@ impl Vm {
 
                     let function_name = chunk.constants[function_name_index].to_string();
                     let function_chunk = self.registry.get(&function_name)
-                        .or_else(|| self.registry.get(&format!("{}{}", context, function_name)));
+                        .or_else(|| self.registry.get(&format!("{}/{}", context, function_name)));
                     if function_chunk.is_none() {
                         return Err(RuntimeError::FunctionNotFound(function_name));
                     } else {