fix lexing, sort of

1 files changed, 49 insertions, 0 deletions

diff --git a/mitmproxy/command_lexer.py b/mitmproxy/command_lexer.py
new file mode 100644
index 00000000..f042f3c9
--- /dev/null
+++ b/mitmproxy/command_lexer.py
@@ -0,0 +1,49 @@
+import ast
+import re
+
+import pyparsing
+
+# TODO: There is a lot of work to be done here.
+# The current implementation is written in a way that _any_ input is valid,
+# which does not make sense once things get more complex.
+
+PartialQuotedString = pyparsing.Regex(
+    re.compile(
+        r'''
+            (["'])  # start quote
+            (?:
+                (?!\1)[^\\]  # unescaped character that is not our quote nor the begin of an escape sequence. We can't use \1 in []
+                |
+                (?:\\.)  # escape sequence
+            )*
+            (?:\1|$)  # end quote
+        ''',
+        re.VERBOSE
+    )
+)
+
+expr = pyparsing.ZeroOrMore(
+    PartialQuotedString
+    | pyparsing.Word(" \r\n\t")
+    | pyparsing.CharsNotIn("""'" \r\n\t""")
+).leaveWhitespace()
+
+
+def quote(val: str) -> str:
+    if val and all(char not in val for char in "'\" \r\n\t"):
+        return val
+    return repr(val)  # TODO: More of a hack.
+
+
+def unquote(x: str) -> str:
+    quoted = (
+            (x.startswith('"') and x.endswith('"'))
+            or
+            (x.startswith("'") and x.endswith("'"))
+    )
+    if quoted:
+        try:
+            x = ast.literal_eval(x)
+        except Exception:
+            x = x[1:-1]
+    return x