Lex (WIP)

1 files changed, 46 insertions, 5 deletions

diff --git a/minicc.cpp b/minicc.cpp
index 07090a8..f0f4e4c 100644
--- a/minicc.cpp
+++ b/minicc.cpp
@@ -35,6 +35,20 @@ BNF Reverse(BNF bnf){
  return {}; // TODO
 }
 
+using index_t = size_t;
+
+struct TreeNode {
+ index_t parent;
+ std::vector<index_t> childs;
+ std::string name;
+};
+
+using Tree = std::map<index_t, TreeNode>;
+
+bool ValidTree(const Tree& tree) {
+ return true; // TODO
+}
+
 std::vector<std::string> Lex(std::string s, std::string Top, BNF bnf)
 {
  std::vector<std::string> result;
@@ -43,13 +57,39 @@ std::vector<std::string> Lex(std::string s, std::string Top, BNF bnf)
  BNF ReverseBNF{ Reverse(bnf)};
 
  std::string Whitespace{"\t \n\r"};
+ std::deque<Tree> candidates;
 
  for (size_t pos{0}; pos < s.size(); pos++) {
   char c{s[pos]};
-  if (token.empty() and Whitespace.find(c) != std::string::npos)
-   continue; // skip whitespace between tokens
-
-  auto Path = GetPath(std::string{1, c}, ReverseBNF, Top);
+  if (Whitespace.find(c) != std::string::npos) {
+   if (candidates.empty()) { // skip
+    if (!token.empty())
+     throw std::runtime_error("Expected empty token, got "s + token);
+   } else { // check candidates
+    bool valid{false};
+    for (const auto& ct : candidates) {
+     if (ValidTree(ct)) {
+      result.push_back(token);
+      token.clear();
+      valid = true;
+     }
+    }
+    if (!valid)
+     throw std::runtime_error("Invalid token: "s + token);
+
+    candidates.clear();
+   }
+  } else { // no whitespace: try to add to tree
+   for (const auto& ct : candidates) {
+    if (!TryAdd(cti, c)) {
+     candidates.erase(i); // no candidate anymore
+    }
+   }
+   if (candidates.empty()) { // no candidates anymore
+   } else {
+   }
+   //token.push_back(c);
+  }
  }
 
  return result;
@@ -95,7 +135,8 @@ TEST_F(Test, BNF) {
   {"digit", {{"0", "1", "2", "3", "4", "5", "6", "7", "8", "9" }}},
   {"identifier-nondigit", {{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",
                             "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "_"}}},
-  {"preprocessing-op-or-punc", {{";"}}},
+  {"preprocessing-op-or-punc", {{";"},
+                                {"="}}},
   {"pp-number", {{"digit"},
                  {"pp-number", "digit"}}}
  };