test: enhance comments and clarify lexical scoping test cases in r1

Author: ryan-gang

test_programs/r1/2.lox

@@ -1,8 +1,7 @@
 ---
 expected_error_type: none
 ---
-// The closure should capture the globally defined function and redeclaring
-// a function with the same name should not affect the closure's capture.
+// This function is used in the function `f` below.
 fun global() {
   print "global";
 }
@@ -12,9 +11,12 @@ fun global() {
     global();
   }
 
-  f();
+  f(); // this should print "global"
+
+  // This function declaration shouldn't affect the usage in `f` above.
   fun global() {
     print "local";
   }
-  f();
+
+  f(); // this should also print "global"
 }

test_programs/r1/3.lox

@@ -1,20 +1,23 @@
 ---
 expected_error_type: none
 ---
-// The `inner` function should capture the variable from the closest outer
-// scope, which is the `outer` function's scope.
 var x = "global";
 
 fun outer() {
   var x = "outer";
 
   fun middle() {
+    // The `inner` function should capture the variable from the closest outer
+    // scope, which is the `outer` function's scope.
     fun inner() {
       print x; // Should capture "outer", not "global"
     }
 
-    inner();
+    inner(); // Should print "outer"
+
+    // This variable declaration shouldn't affect the usage in `inner` above.
     var x = "middle";
+
     inner(); // Should still print "outer"
   }
 

test_programs/r1/4.lox

@@ -1,14 +1,14 @@
 ---
 expected_error_type: none
 ---
-// The closure should capture the `count` variable from the global scope
-// and increment it. Reassigning the `count` variable in the local scope
-// should not affect the closure's capture.
 var count = 0;
 
 {
+  // The `counter` function should use the `count` variable from the
+  // global scope.
   fun makeCounter() {
     fun counter() {
+      // This should increment the `count` variable from the global scope.
       count = count + 1;
       print count;
     }
@@ -19,6 +19,8 @@ var count = 0;
   counter1(); // Should print 1
   counter1(); // Should print 2
 
-  var count = 0; // This local variable shouldn't affect our counter
+  // This variable declaration shouldn't affect our counter.
+  var count = 0;
+
   counter1(); // Should print 3
 }