Update docs for escaping

docs/syntax.md

@@ -78,17 +78,7 @@ Chat IDs are actually variables that contain an entire chat history [(example us
 
 # Escaping
 
-Normally, you would not need escaping, e.g. `[:foo` will evaluate to `[:foo` as text. But if you want to specify a MetaPrompt expression literally, use `\` before the `[` character: `\[:foo]` will evaluate to `[:foo]` as text, without special meaning. You can escape `\` with another `\`, but only if it is positioned before a `[`:
-
-`\foo` → (text `\foo`)
-
-`\\` → (text `\\`)
-
-`\[:foo]` → (text `[:foo]`)
-
-`\\[:foo]` → (text `\\`) (variable `foo`)
-
-`\[some text` -> (text `[some text`) - note that in this case the `\` character disappears, although escaping does not happen because `[some text` is not a special MetaPrompt construct.
+`[` and `]` must be escaped using `\\`.
 
 # Modules
 

python/tests/test_parser.py

@@ -1,3 +1,4 @@
+# TODO: add negative tests
 from parse_metaprompt import (
     parse_metaprompt,
     extract_tokens,
@@ -160,6 +161,11 @@ def test_absence_of_comment():
     assert result == [t("# asd")]
 
 
+def test_bslash():
+    result = parse("\\")
+    assert result == [t("\\")]
+
+
 def test_kw_EQ_KW():
     result = parse("==")
     assert result == [t("==")]