Added basic implentation for where

src/core/tokenizer.py

@@ -266,10 +266,10 @@ class Tokenizer:
                 self.column = 1
                 self.line += 1
             elif c == "c" and self.i + 1 < self.text_len and self.text[self.i + 1] == ":":
-                concept_name = self.eat_concept_name(self.i + 2, self.line, self.column)
-                yield Token(TokenKind.CONCEPT, concept_name, self.i, self.line, self.column)
-                self.i += len(concept_name) + 3
-                self.column += len(concept_name) + 3
+                name, id, length = self.eat_concept(self.i + 2, self.line, self.column + 2)
+                yield Token(TokenKind.CONCEPT, (name, id), self.i, self.line, self.column)
+                self.i += length + 2
+                self.column += length + 2
             elif c.isalpha() or c == "_":
                 identifier = self.eat_identifier(self.i)
                 token_type = TokenKind.KEYWORD if identifier in self.KEYWORDS else TokenKind.IDENTIFIER
@@ -297,31 +297,41 @@ class Tokenizer:
 
         yield Token(TokenKind.EOF, "", self.i, self.line, self.column)
 
-    def eat_concept_name(self, start, line, column):
-        result = ""
+    def eat_concept(self, start, line, column):
+        key, id, buffer = None, None, ""
         i = start
-        end_colon_found = False
+        processing_key = True
 
         while i < self.text_len:
-            c = self.text[i]
 
+            c = self.text[i]
             if c == "\n":
-                raise LexerError(f"New line is forbidden in concept name", result, i, line, column + 2 + len(result))
+                raise LexerError(f"New line in concept name", self.text[start:i], i, line, column + i - start)
 
             if c == ":":
-                end_colon_found = True
+                if processing_key:
+                    key = buffer if buffer else None
+                else:
+                    id = buffer if buffer else None
+                i += 1  # eat the colon
                 break
 
-            result += c
+            if c == "|":
+                key = buffer if buffer else None
+                buffer = ""
+                processing_key = False
+                i += 1
+                continue
+
+            buffer += c
             i += 1
+        else:
+            raise LexerError(f"Missing ending colon", self.text[start:i], i, line, column + i - start)
 
-        if not end_colon_found:
-            raise LexerError(f"Missing ending colon", result, i, line, column + 2 + len(result))
+        if (key, id) == (None, None):
+            raise LexerError(f"Concept identifiers not found", "", start, line, column)
 
-        if result == "":
-            raise LexerError(f"Concept name not found", result, start, line, column + 2 + len(result))
-
-        return result
+        return key, id, i - start
 
     def eat_whitespace(self, start):
         result = self.text[start]