small fixes

src/indent_stack.hpp

@@ -8,11 +8,12 @@ enum class IndentAction
 };
 
 constexpr int TAB_WIDTH = 8;
+constexpr char TAB = '\t';
 
 class IndentStack
 {
     std::stack<int> indent_stack;
-    int pending_dedents = 0;
+    int dedent_queue = 0;
 
 public:
     IndentStack() { indent_stack.push(0); }
@@ -32,15 +33,15 @@ public:
             return IndentAction::Indent;
         }
 
-        while (indent_stack.top() > spaces)
+        while (!indent_stack.empty() && indent_stack.top() > spaces)
         {
             indent_stack.pop();
-            pending_dedents++;
+            dedent_queue++;
         }
 
-        if (pending_dedents > 0)
+        if (dedent_queue > 0)
         {
-            pending_dedents--;
+            dedent_queue--;
             return IndentAction::Dedent;
         }
 
@@ -49,11 +50,11 @@ public:
 
     bool popDedent()
     {
-        if (pending_dedents <= 0)
+        if (dedent_queue <= 0)
         {
             return false;
         }
-        pending_dedents--;
+        dedent_queue--;
         return true;
     }
 
@@ -62,18 +63,24 @@ public:
         int spaces = 0;
         for (int i = 0; i < length; i++)
         {
-            spaces += (text[i] == '\t') ? TAB_WIDTH : 1;
+            if (text[i] == TAB)
+            {
+                spaces += TAB_WIDTH - (spaces % TAB_WIDTH);
+                continue;
+            }
+            spaces++;
         }
         return spaces;
     }
 
     bool hasRemainingDedents()
     {
-        return pending_dedents > 0;
+        return dedent_queue > 0;
     }
 
     IndentAction closeBlock()
     {
+        // Force indentation reset at EOF
         return updateIndentation(0);
     }
 };

src/lexer.l

@@ -13,7 +13,7 @@
 ^[ \t]*\r?\n            { /* Ignore lines containing whitespace only */ }
 ^[ \t]*#.*\n            { /* Ignore comment-only lines */ }
 
-^[ \t]* {
+^[ \t]+ {
     int col = indent_stack.calculateColumn(yytext, yyleng);
     auto action = indent_stack.updateIndentation(col);
 
@@ -38,7 +38,6 @@ in       { return yy::parser::token::TOK_KW_IN; }
 \-                      { return yy::parser::token::TOK_MINUS; }
 
 \"                      { yymore(); BEGIN(STRING); }
-<STRING>\"\" { yymore(); }
 <STRING>\"              { BEGIN(INITIAL); yylval->as<std::string>() = yytext; return yy::parser::token::TOK_STRING; }
 <STRING>.               { yymore(); }
 
@@ -46,4 +45,4 @@ in       { return yy::parser::token::TOK_KW_IN; }
 [A-Za-z_][A-Za-z0-9_]*  { yylval->as<std::string>() = yytext; return yy::parser::token::TOK_IDENTIFIER; }
 
 <<EOF>>                 { return yy::parser::token::TOK_EOF; }
-.           { /* ignore other characters */ }
+.                       { }