Fix errors with eval/use of scripts

cheatsheet.md

@@ -269,4 +269,6 @@ use("filename") // evals file exactly once and returns value of last statement
                 // if the file had already been 'used' nothing happens and undefined is returned
 ```
 
+Both `use` and `eval_file` search the 'usepaths' passed to the ChaiScript constructor
+
 

include/chaiscript/language/chaiscript_engine.hpp

@@ -297,13 +297,23 @@ namespace chaiscript
       }
     }
 
-    /// Evaluates the given string, used during eval() inside of a script
+    /// Evaluates the given file and looks in the 'use' paths
     const Boxed_Value internal_eval_file(const std::string &t_filename) {
-      try {
-        return do_eval(load_file(t_filename), t_filename, true);
-      } catch (const exception::eval_error &t_ee) {
-        throw Boxed_Value(t_ee);
+      for (const auto &path : m_usepaths)
+      {
+        try {
+          const auto appendedpath = path + t_filename;
+          return do_eval(load_file(appendedpath), appendedpath, true);
+        } catch (const exception::file_not_found_error &) {
+          // failed to load, try the next path
+        } catch (const exception::eval_error &t_ee) {
+          throw Boxed_Value(t_ee);
+        }
       }
+
+      // failed to load by any name
+      throw exception::file_not_found_error(t_filename);
+
     }
 
 

unittests/eval_file.chai

@@ -1,10 +1,19 @@
 
 try {
   eval_file("use.inc")
-  assert(true)
+  assert_true(true)
+  print("used use.inc")
+} catch (e) {
+  print("error: " + e.what())
+  assert_true(false)
+}
 
+
+try {
   //we expect this second eval_file to fail because of a function redefinition
   eval_file("use.inc")
-  assert(false)
+  assert_true(false)
+  print("used use.inc x2")
 } catch (e) {
+  assert_true(true)
 }

unittests/logical_short_circuiting.chai

@@ -1,7 +1,7 @@
 
 def shouldnt_execute()
 {
-  assert(false)
+  assert_true(false)
 }