Allow multi-character parameters

kalk/src/analysis.rs

@@ -484,6 +484,13 @@ fn analyse_var(
         with_adjacent(Expr::Var(identifier), adjacent_factor, adjacent_exponent)
     } else if context.symbol_table.contains_var(&identifier.pure_name)
         || (identifier.pure_name.len() == 1 && !context.in_equation)
+        || context.current_function_parameters.is_some()
+            && context
+                .current_function_parameters
+                .as_ref()
+                .unwrap()
+                .iter()
+                .any(|param| param[2..] == identifier.pure_name)
     {
         with_adjacent(
             build_var(context, &identifier.full_name),

tests/functions.kalker

@@ -1,5 +1,5 @@
 x = 3
 f(x) = 2*x
-g(x, y) = 2*x*y
+g(x, long_name) = 2*x*long_name
 
 f(x) = 6 and fx = 6 and x = 3 and g(x, x + 1) = 24 and sqrt4 = 2