move src into subdir

1 files changed, 43 insertions, 0 deletions

diff --git a/src/eval_env.h b/src/eval_env.h
new file mode 100644
index 0000000..a630e7a
--- /dev/null
+++ b/src/eval_env.h
@@ -0,0 +1,43 @@
+#ifndef NINJA_EVAL_ENV_H_
+#define NINJA_EVAL_ENV_H_
+
+// A scope for variable lookups.
+struct Env {
+  virtual string LookupVariable(const string& var) = 0;
+};
+
+// A standard scope, which contains a mapping of variables to values
+// as well as a pointer to a parent scope.
+struct BindingEnv : public Env {
+  virtual string LookupVariable(const string& var) {
+    map<string, string>::iterator i = bindings_.find(var);
+    if (i != bindings_.end())
+      return i->second;
+    if (parent_)
+      return parent_->LookupVariable(var);
+    return "";
+  }
+  void AddBinding(const string& key, const string& val) {
+    bindings_[key] = val;
+  }
+
+  map<string, string> bindings_;
+  Env* parent_;
+};
+
+// A tokenized string that contains variable references.
+// Can be evaluated relative to an Env.
+struct EvalString {
+  bool Parse(const string& input, string* err);
+  string Evaluate(Env* env) const;
+
+  const string& unparsed() const { return unparsed_; }
+  const bool empty() const { return unparsed_.empty(); }
+
+  string unparsed_;
+  enum TokenType { RAW, SPECIAL };
+  typedef vector<pair<string, TokenType> > TokenList;
+  TokenList parsed_;
+};
+
+#endif  // NINJA_EVAL_ENV_H_