diff options
Diffstat (limited to 'src/eval_env.h')
| -rw-r--r-- | src/eval_env.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/eval_env.h b/src/eval_env.h index cc61a38..517066d 100644 --- a/src/eval_env.h +++ b/src/eval_env.h @@ -12,6 +12,7 @@ struct Env { // A standard scope, which contains a mapping of variables to values // as well as a pointer to a parent scope. struct BindingEnv : public Env { + BindingEnv() : parent_(NULL) {} virtual string LookupVariable(const string& var) { map<string, string>::iterator i = bindings_.find(var); if (i != bindings_.end()) |