1133 - more reorg of commandline parsing

1. Drop the ability to run just some C++ tests. It's a lousy interface
to use line numbers, we can't selectively run mu tests, we haven't used
it in a while because our tests run plenty fast, and it's complicating
other parts, like Next_recipe_number and test space handling.

2. Create a new layer right up top to show the usage message and all the
different forms that are possible. Good for documentation until we come
up with a way to put the different forms in their own layers. At least
it's out of the test layer now.

3. Strengthen the assertion that no recipes exist in test space before
we start running any sorts of tests. Earlier it was possible for
files loaded explicitly to overflow into test space because we were
asserting before load, not after. Now we check if we need to run tests,
load all files, then make the assertion, run tests, and exit if
necessary.

Now we don't need to mess with commandline args at all in layer 50.
That's a sign that we're on the right track.

1 files changed, 17 insertions, 55 deletions

diff --git a/cpp/002test b/cpp/002test
index f704f7f0..6f0fcaa8 100644
--- a/cpp/002test
+++ b/cpp/002test
@@ -16,6 +16,7 @@ const test_fn Tests[] = {
   #include "test_list"  // auto-generated; see makefile
 };
 
+bool Run_tests = false;
 bool Passed = true;  // set this to false inside any test to indicate failure
 long Num_failures = 0;
 
@@ -36,40 +37,24 @@ long Num_failures = 0;
     return;  /* Currently we stop at the very first failure. */ \
   }
 
-:(before "End Main")
-if (argc <= 1 || is_equal(argv[1], "--help")) {
-  // need some way to distribute this across layers
-  cerr << "To load files and run 'main': mu file1.mu file2.mu ...\n"
-       << "To run all core tests: mu test\n"
-       << "To load files and run tests defined in them: mu test file1.mu file2.mu ...\n"
-       << "To run just some C++ tests in `test_list` file: mu test n1 n2 ...\n"
-       << "  (look up n1 n2 ... by running `grep -n` on test_list`)\n"
-       ;
-  return 0;
-}
+:(before "End Commandline Parsing")
 if (argc > 1 && is_equal(argv[1], "test")) {
-  // End Test Run Initialization
-  if (argc == 2) {
-    run_tests();
-    cerr << '\n';
-    if (Num_failures > 0)
-      cerr << Num_failures << " failure"
-           << (Num_failures > 1 ? "s" : "")
-           << '\n';
-    return 0;
-  }
-  if (is_number(argv[2])) {
-    // all args are line numbers in test_file specifying tests to run
-    run_tests(argc, argv);
-    cerr << '\n';
-    if (Num_failures > 0)
-      cerr << Num_failures << " failure"
-           << (Num_failures > 1 ? "s" : "")
-           << '\n';
-    return 0;
-  }
+  Run_tests = true;  --argc;  ++argv;  // shift 'test' out of commandline args
+}
+
+:(before "End Main")
+if (Run_tests) {
+  // Test Runs
+  // we run some tests and then exit; assume no state need be maintained afterward
 
-  // End Test Runs
+  // End Test Run Initialization
+  run_tests();
+  cerr << '\n';
+  if (Num_failures > 0)
+    cerr << Num_failures << " failure"
+         << (Num_failures > 1 ? "s" : "")
+         << '\n';
+  return 0;
 }
 
 :(code)
@@ -82,12 +67,6 @@ void run_tests() {
   // End Tests
 }
 
-void run_tests(int argc, char* argv[]) {
-  for (int i = 2; i < argc; ++i) {
-    run_test(to_int(argv[i])-1);
-  }
-}
-
 void run_test(size_t i) {
   if (i >= sizeof(Tests)/sizeof(Tests[0])) {
     cerr << "no test " << i << '\n';
@@ -102,10 +81,6 @@ void run_test(size_t i) {
   // End Test Teardown
 }
 
-bool is_equal(char* s, const char* lit) {
-  return strncmp(s, lit, strlen(lit)) == 0;
-}
-
 bool is_number(const string& s) {
   return s.find_first_not_of("0123456789-.") == string::npos;
 }
@@ -120,16 +95,3 @@ int to_int(string n) {
 :(before "End Includes")
 #include<assert.h>
 #include<cstdlib>
-
-#include<iostream>
-using std::istream;
-using std::ostream;
-using std::iostream;
-using std::cin;
-using std::cout;
-using std::cerr;
-
-#include<cstring>
-#include<string>
-using std::string;
-#define NOT_FOUND string::npos  // macro doesn't complain about redef