1 files changed, 198 insertions, 0 deletions
diff --git a/ptpython/utils.py b/ptpython/utils.py
new file mode 100644
index 0000000..2fb24a4
--- /dev/null
+++ b/ptpython/utils.py
@@ -0,0 +1,198 @@
+"""
+For internal use only.
+"""
+import re
+from typing import Callable, Iterable, Type, TypeVar, cast
+
+from prompt_toolkit.formatted_text import to_formatted_text
+from prompt_toolkit.formatted_text.utils import fragment_list_to_text
+from prompt_toolkit.mouse_events import MouseEvent, MouseEventType
+
+__all__ = [
+    "has_unclosed_brackets",
+    "get_jedi_script_from_document",
+    "document_is_multiline_python",
+    "unindent_code",
+]
+
+
+def has_unclosed_brackets(text: str) -> bool:
+    """
+    Starting at the end of the string. If we find an opening bracket
+    for which we didn't had a closing one yet, return True.
+    """
+    stack = []
+
+    # Ignore braces inside strings
+    text = re.sub(r"""('[^']*'|"[^"]*")""", "", text)  # XXX: handle escaped quotes.!
+
+    for c in reversed(text):
+        if c in "])}":
+            stack.append(c)
+
+        elif c in "[({":
+            if stack:
+                if (
+                    (c == "[" and stack[-1] == "]")
+                    or (c == "{" and stack[-1] == "}")
+                    or (c == "(" and stack[-1] == ")")
+                ):
+                    stack.pop()
+            else:
+                # Opening bracket for which we didn't had a closing one.
+                return True
+
+    return False
+
+
+def get_jedi_script_from_document(document, locals, globals):
+    import jedi  # We keep this import in-line, to improve start-up time.
+
+    # Importing Jedi is 'slow'.
+
+    try:
+        return jedi.Interpreter(
+            document.text,
+            path="input-text",
+            namespaces=[locals, globals],
+        )
+    except ValueError:
+        # Invalid cursor position.
+        # ValueError('`column` parameter is not in a valid range.')
+        return None
+    except AttributeError:
+        # Workaround for #65: https://github.com/jonathanslenders/python-prompt-toolkit/issues/65
+        # See also: https://github.com/davidhalter/jedi/issues/508
+        return None
+    except IndexError:
+        # Workaround Jedi issue #514: for https://github.com/davidhalter/jedi/issues/514
+        return None
+    except KeyError:
+        # Workaroud for a crash when the input is "u'", the start of a unicode string.
+        return None
+    except Exception:
+        # Workaround for: https://github.com/jonathanslenders/ptpython/issues/91
+        return None
+
+
+_multiline_string_delims = re.compile("""[']{3}|["]{3}""")
+
+
+def document_is_multiline_python(document):
+    """
+    Determine whether this is a multiline Python document.
+    """
+
+    def ends_in_multiline_string() -> bool:
+        """
+        ``True`` if we're inside a multiline string at the end of the text.
+        """
+        delims = _multiline_string_delims.findall(document.text)
+        opening = None
+        for delim in delims:
+            if opening is None:
+                opening = delim
+            elif delim == opening:
+                opening = None
+        return bool(opening)
+
+    if "\n" in document.text or ends_in_multiline_string():
+        return True
+
+    def line_ends_with_colon() -> bool:
+        return document.current_line.rstrip()[-1:] == ":"
+
+    # If we just typed a colon, or still have open brackets, always insert a real newline.
+    if (
+        line_ends_with_colon()
+        or (
+            document.is_cursor_at_the_end
+            and has_unclosed_brackets(document.text_before_cursor)
+        )
+        or document.text.startswith("@")
+    ):
+        return True
+
+    # If the character before the cursor is a backslash (line continuation
+    # char), insert a new line.
+    elif document.text_before_cursor[-1:] == "\\":
+        return True
+
+    return False
+
+
+_T = TypeVar("_T", bound=Callable[[MouseEvent], None])
+
+
+def if_mousedown(handler: _T) -> _T:
+    """
+    Decorator for mouse handlers.
+    Only handle event when the user pressed mouse down.
+
+    (When applied to a token list. Scroll events will bubble up and are handled
+    by the Window.)
+    """
+
+    def handle_if_mouse_down(mouse_event: MouseEvent):
+        if mouse_event.event_type == MouseEventType.MOUSE_DOWN:
+            return handler(mouse_event)
+        else:
+            return NotImplemented
+
+    return cast(_T, handle_if_mouse_down)
+
+
+_T_type = TypeVar("_T_type", bound=Type)
+
+
+def ptrepr_to_repr(cls: _T_type) -> _T_type:
+    """
+    Generate a normal `__repr__` method for classes that have a `__pt_repr__`.
+    """
+    if not hasattr(cls, "__pt_repr__"):
+        raise TypeError(
+            "@ptrepr_to_repr can only be applied to classes that have a `__pt_repr__` method."
+        )
+
+    def __repr__(self) -> str:
+        return fragment_list_to_text(to_formatted_text(cls.__pt_repr__(self)))
+
+    cls.__repr__ = __repr__  # type:ignore
+    return cls
+
+
+def unindent_code(text: str) -> str:
+    """
+    Remove common leading whitespace when all lines are indented.
+    """
+    lines = text.splitlines(keepends=True)
+
+    # Look for common prefix.
+    common_prefix = _common_whitespace_prefix(lines)
+
+    # Remove indentation.
+    lines = [line[len(common_prefix) :] for line in lines]
+
+    return "".join(lines)
+
+
+def _common_whitespace_prefix(strings: Iterable[str]) -> str:
+    """
+    Return common prefix for a list of lines.
+    This will ignore lines that contain whitespace only.
+    """
+    # Ignore empty lines and lines that have whitespace only.
+    strings = [s for s in strings if not s.isspace() and not len(s) == 0]
+
+    if not strings:
+        return ""
+
+    else:
+        s1 = min(strings)
+        s2 = max(strings)
+
+        for i, c in enumerate(s1):
+            if c != s2[i] or c not in " \t":
+                return s1[:i]
+
+        return s1