Simple semantic analysis structure

semantic/src/top_level.rs

@@ -0,0 +1,18 @@
+use std::collections::HashMap;
+
+pub struct TypeSymbol {
+    export: bool,
+    name: String,
+}
+
+pub struct FunctionSymbol {
+    export: bool,
+    name: String,
+    params: HashMap<String, TypeSymbol>,
+}
+
+pub struct StructSymbol {
+    export: bool,
+    name: String,
+    fields: HashMap<String, TypeSymbol>,
+}