6 files changed, 53 insertions, 38 deletions
diff --git a/cpp/build_and_test_until b/cpp/build_and_test_until
index d23de2e1..cd0db64b 100755
--- a/cpp/build_and_test_until
+++ b/cpp/build_and_test_until
@@ -5,7 +5,8 @@
 set -e
 set -v
 make tangle/tangle
-./tangle/tangle --until $* |grep -v "^\s*//:" > mu.cc
+make enumerate/enumerate
+./tangle/tangle $(./enumerate/enumerate --until $* |grep -v '.mu$') |grep -v "^\s*//:" > mu.cc
 make autogenerated_lists
 g++ -g -Wall -Wextra -fno-strict-aliasing mu.cc -o mu
 ./mu test
diff --git a/cpp/enumerate/enumerate.cc b/cpp/enumerate/enumerate.cc
new file mode 100644
index 00000000..02349213
--- /dev/null
+++ b/cpp/enumerate/enumerate.cc
@@ -0,0 +1,35 @@
+#include<cstdlib>
+#include<dirent.h>
+#include<vector>
+using std::vector;
+#include<string>
+using std::string;
+#include<iostream>
+using std::cout;
+
+int enumerate_files_in_cwd_until(string last_file);
+string flag_value(const string& flag, int argc, const char* argv[]);
+
+int main(int argc, const char* argv[]) {
+  return enumerate_files_in_cwd_until(flag_value("--until", argc, argv));
+}
+
+int enumerate_files_in_cwd_until(string last_file) {
+  dirent** files;
+  int num_files = scandir(".", &files, NULL, alphasort);
+  for (int i = 0; i < num_files; ++i) {
+    string curr_file = files[i]->d_name;
+    if (!isdigit(curr_file[0])) continue;
+    if (!last_file.empty() && curr_file > last_file) break;
+    cout << curr_file << '\n';
+  }
+  // don't bother freeing files
+  return 0;
+}
+
+string flag_value(const string& flag, int argc, const char* argv[]) {
+  for (int i = 1; i < argc-1; ++i)
+    if (string(argv[i]) == flag)
+      return argv[i+1];
+  return "";
+}
diff --git a/cpp/enumerate/makefile b/cpp/enumerate/makefile
new file mode 100644
index 00000000..2c685cd4
--- /dev/null
+++ b/cpp/enumerate/makefile
@@ -0,0 +1,5 @@
+tangle: makefile
+	g++ -O3 -Wall -Wextra -fno-strict-aliasing enumerate.cc -o enumerate
+
+clean:
+	rm -rf enumerate
diff --git a/cpp/makefile b/cpp/makefile
index d49d8887..a42667c9 100644
--- a/cpp/makefile
+++ b/cpp/makefile
@@ -1,14 +1,17 @@
-mu: makefile tangle/tangle mu.cc
+mu: makefile enumerate/enumerate tangle/tangle mu.cc
 	g++ -g -Wall -Wextra -fno-strict-aliasing mu.cc -o mu
 
 # To see what the program looks like after all layers have been applied, read
 # mu.cc
 mu.cc: 0*
-	./tangle/tangle --until 999 |grep -v "^\s*//:" > mu.cc
+	./tangle/tangle $$(./enumerate/enumerate --until 999 |grep -v '.mu$$') |grep -v "^\s*//:" > mu.cc
 	@make autogenerated_lists >/dev/null
 
+enumerate/enumerate:
+	cd enumerate && make && ./enumerate test
+
 tangle/tangle:
-	cd tangle && make && tangle test
+	cd tangle && make && ./tangle test
 
 # auto-generated files; by convention they end in '_list'.
 .PHONY: autogenerated_lists test clena 
@@ -27,5 +30,6 @@ test_list: mu.cc
 
 clena: clean
 clean:
+	cd enumerate && make clean
 	cd tangle && make clean
 	rm -rf mu.cc mu *_list
diff --git a/cpp/tangle/002main.cc b/cpp/tangle/002main.cc
index 04d10c8d..aaa91e6f 100644
--- a/cpp/tangle/002main.cc
+++ b/cpp/tangle/002main.cc
@@ -1,14 +1,7 @@
-string Last_file = "";
 int main(int argc, const char* argv[]) {
-  Last_file = flag_value("--until", argc, argv);
   if (flag("test", argc, argv))
     return run_tests();
-  return tangle_files_in_cwd();
-}
-
-bool eof(istream& in) {
-  in.peek();
-  return in.eof();
+  return tangle(argc, argv);
 }
 
 bool flag(const string& flag, int argc, const char* argv[]) {
diff --git a/cpp/tangle/030tangle.cc b/cpp/tangle/030tangle.cc
index 52bf4c61..ec34c944 100644
--- a/cpp/tangle/030tangle.cc
+++ b/cpp/tangle/030tangle.cc
@@ -1,12 +1,9 @@
 #include<sys/param.h>
 
-int tangle_files_in_cwd() {
+int tangle(int argc, const char* argv[]) {
   list<string> result;
-  vector<char*> files = sorted_files(".", /*no extension*/ "");
-  for (vector<char*>::iterator p = files.begin(); p != files.end(); ++p) {
-    if ((*p)[0] < '0' || (*p)[0] > '9') continue;
-    if (!Last_file.empty() && *p > Last_file) break;
-    ifstream in(*p);
+  for (int i = 1; i < argc; ++i) {
+    ifstream in(argv[i]);
     tangle(in, result);
   }
   for (list<string>::iterator p = result.begin(); p != result.end(); ++p)
@@ -367,23 +364,3 @@ string trim(const string& s) {
   ++last;
   return string(first, last);
 }
-
-#include<dirent.h>
-
-vector<char*> sorted_files(const char* dirname, const char* ext) {
-  vector<char*> result;
-  dirent** files;
-  int num_files = scandir(dirname, &files, NULL, alphasort);
-  for (int i = 0; i < num_files; ++i) {
-    unsigned long n = strlen(files[i]->d_name), extn = strlen(ext);
-    if (n < extn) continue;
-    if (strncmp(&files[i]->d_name[n-extn], ext, extn)) continue;
-    if (!isdigit(files[i]->d_name[0])) continue;
-    char* s = new char[n+1];
-    strncpy(s, files[i]->d_name, n+1);
-    result.push_back(s);
-    free(files[i]);
-  }
-  free(files);
-  return result;
-}