feat: function call checks

lib/edlang_check/src/lib.rs

@@ -182,5 +182,21 @@ pub fn lowering_error_to_report(
                 )
                 .finish()
         }
+        LoweringError::ParamCountMismatch {
+            span,
+            has_args,
+            needs,
+            file_id,
+        } => {
+            let path = session.file_paths[file_id].display().to_string();
+            Report::build(ReportKind::Error, path.clone(), span.lo)
+                .with_code("ParamCountMismatch")
+                .with_label(
+                    Label::new((path, span.into()))
+                        .with_message(format!("function call parameter count mismatch: has {}, needs {}.", has_args, needs))
+                        .with_color(colors.next()),
+                )
+                .finish()
+        },
     }
 }

lib/edlang_lowering/src/errors.rs

@@ -63,4 +63,11 @@ pub enum LoweringError {
         name: String,
         file_id: usize,
     },
+    #[error("parameter count mismatch to function call")]
+    ParamCountMismatch {
+        span: Span,
+        has_args: usize,
+        needs: usize,
+        file_id: usize,
+    },
 }

lib/edlang_lowering/src/lib.rs

@@ -1000,12 +1000,29 @@ fn lower_fn_call(
         }
     };
 
-    let mut args = Vec::new();
+    if args_ty.len() != info.params.len() {
+        return Err(LoweringError::ParamCountMismatch {
+            span: info.span,
+            has_args: info.params.len(),
+            needs: args_ty.len(),
+            file_id: builder.file_id,
+        });
+    }
 
-    assert_eq!(args_ty.len(), info.params.len(), "param length mismatch");
+    let mut args = Vec::new();
 
     for (arg, arg_ty) in info.params.iter().zip(args_ty) {
-        let (rvalue, _rvalue_ty, _span) = lower_expr(builder, arg, Some(&arg_ty))?;
+        let (rvalue, rvalue_ty, arg_span) = lower_expr(builder, arg, Some(&arg_ty))?;
+
+        if rvalue_ty != arg_ty.kind {
+            return Err(LoweringError::UnexpectedType {
+                span: arg_span,
+                found: rvalue_ty,
+                expected: arg_ty,
+                file_id: builder.file_id,
+            });
+        }
+
         args.push(rvalue);
     }