semantic: separate assignments from definitions

Variables are no longer implicitly defined

compiler/__main__.py

@@ -6,9 +6,9 @@ from pprint import pprint
 
 from . import semantic
 from .errors import CompilationError
+from .lexer import Lexer, Tokens
 from .logger import rootLogger, LogLevel
 from .parser import Parser
-from .lexer import Lexer, Tokens
 
 
 def main():
@@ -19,14 +19,17 @@ def main():
 
     data = """
             {
-                byte = 42;
+                let byte: uint32 = 42;
             }
+            let byte: uint32;
+            
             2 + 8 - 1 * (byte = 3 + 5)
             / (byte = 255) + byte;
             byte = byte + byte;
             {
-                a = byte;
+                let a: uint32 = byte;
             }
+            { let b: uint32; }
             """
     if not args.mock:
         data = sys.stdin.read().strip()

compiler/nodes.py

@@ -370,6 +370,13 @@ class Definition(Assignment):
     def pure(self) -> bool:
         return self.value is None
 
+    def semantic_analysis(self, context: semantic.Context):
+        super(Assignment, self).semantic_analysis(context)
+        name = self.identifier.value
+        variable = context.define_variable(name, type_identifier=self.type_identifier, value=self.value)
+        self.variable = variable
+        logger.debug(f"Added variable {variable} to context {context.fully_qualified_name()}")
+
 
 Number = Float | Integer
 Value = BinaryOperation | Number | Variable | Expression

compiler/semantic.py

@@ -4,6 +4,7 @@ import abc
 from typing import Literal
 
 from . import nodes
+from .errors import SemanticAnalysisError
 from .logger import Logger
 from .typechecking import typecheck
 
@@ -39,11 +40,12 @@ class Type(SymbolABC):
 
 class Variable(SymbolABC):
     @typecheck
-    def __init__(self, context: Context, name: str, value: nodes.Value | None = None):
+    def __init__(self, context: Context, name: str, value: nodes.Value | None = None, typedef: Type | None = None):
         super().__init__(context, name, value)
+        self.type = typedef if typedef is not None else context.get_type("__unknown")
 
     def __str__(self):
-        return f"{self.__class__.__name__}({self.name})"
+        return f"{self.__class__.__name__}({self.name} : {self.type.fully_qualified_name()})"
 
 
 class Context:
@@ -79,13 +81,29 @@ class Context:
     def get_variable(self, name: str) -> Variable | None:
         return self._resolve_symbol("variables", name)
 
-    def set_variable(self, name: str, value: nodes.Value) -> Variable:
+    def define_variable(self, name: str, type_identifier: nodes.Identifier, value: nodes.Value) -> Variable:
-        variable: Variable
         if name in self.variables:
+            raise SemanticAnalysisError(value.location())
+
+        typedef = self.get_type(type_identifier.value)
+        if typedef is None:
+            raise SemanticAnalysisError(location=type_identifier.location(),
+                                        message=f"Unknown type '{type_identifier.value}'")
+
+        variable = Variable(self, name, value, typedef)
+
+        self.variables[name] = variable
+
+        return variable
+
+    def set_variable(self, name: str, value: nodes.Value) -> Variable:
+        assert value is not None
+
+        if name not in self.variables:
+            raise SemanticAnalysisError(value.location(),
+                                        message=f"Can't assign a value to undeclared variable '{name}'")
         variable = self.variables[name]
         variable.definitions += [value]
-        else:
-            variable = Variable(self, name, value)
 
         self.variables[name] = variable