jupyter

packages/python/yap_kernel/yap_ipython/terminal/ptutils.py

@@ -0,0 +1,160 @@
+"""prompt-toolkit utilities
+
+Everything in this module is a private API,
+not to be used outside yap_ipython.
+"""
+
+# Copyright (c) yap_ipython Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+import unicodedata
+from wcwidth import wcwidth
+
+from yap_ipython.core.completer import (
+    provisionalcompleter, cursor_to_position,
+    _deduplicate_completions)
+from prompt_toolkit.completion import Completer, Completion
+from prompt_toolkit.layout.lexers import Lexer
+from prompt_toolkit.layout.lexers import PygmentsLexer
+
+import pygments.lexers as pygments_lexers
+
+_completion_sentinel = object()
+
+def _elide(string, *, min_elide=30):
+    """
+    If a string is long enough, and has at least 2 dots,
+    replace the middle part with ellipses.
+
+    If three consecutive dots, or two consecutive dots are encountered these are
+    replaced by the equivalents HORIZONTAL ELLIPSIS or TWO DOT LEADER unicode
+    equivalents
+    """
+    string = string.replace('...','\N{HORIZONTAL ELLIPSIS}')
+    string = string.replace('..','\N{TWO DOT LEADER}')
+    if len(string) < min_elide:
+        return string
+
+    parts = string.split('.')
+
+    if len(parts) <= 3:
+        return string
+
+    return '{}.{}\N{HORIZONTAL ELLIPSIS}{}.{}'.format(parts[0], parts[1][0], parts[-2][-1], parts[-1])
+
+
+def _adjust_completion_text_based_on_context(text, body, offset):
+    if text.endswith('=') and len(body) > offset and body[offset] is '=':
+        return text[:-1]
+    else:
+        return text
+
+
+class IPythonPTCompleter(Completer):
+    """Adaptor to provide yap_ipython completions to prompt_toolkit"""
+    def __init__(self, ipy_completer=None, shell=None, patch_stdout=None):
+        if shell is None and ipy_completer is None:
+            raise TypeError("Please pass shell=an InteractiveShell instance.")
+        self._ipy_completer = ipy_completer
+        self.shell = shell
+        if patch_stdout is None:
+            raise TypeError("Please pass patch_stdout")
+        self.patch_stdout = patch_stdout
+
+    @property
+    def ipy_completer(self):
+        if self._ipy_completer:
+            return self._ipy_completer
+        else:
+            return self.shell.Completer
+
+    def get_completions(self, document, complete_event):
+        if not document.current_line.strip():
+            return
+        # Some bits of our completion system may print stuff (e.g. if a module
+        # is imported). This context manager ensures that doesn't interfere with
+        # the prompt.
+
+        with self.patch_stdout(), provisionalcompleter():
+            body = document.text
+            cursor_row = document.cursor_position_row
+            cursor_col = document.cursor_position_col
+            cursor_position = document.cursor_position
+            offset = cursor_to_position(body, cursor_row, cursor_col)
+            yield from self._get_completions(body, offset, cursor_position, self.ipy_completer)
+
+    @staticmethod
+    def _get_completions(body, offset, cursor_position, ipyc):
+        """
+        Private equivalent of get_completions() use only for unit_testing.
+        """
+        debug = getattr(ipyc, 'debug', False)
+        completions = _deduplicate_completions(
+            body, ipyc.completions(body, offset))
+        for c in completions:
+            if not c.text:
+                # Guard against completion machinery giving us an empty string.
+                continue
+            text = unicodedata.normalize('NFC', c.text)
+            # When the first character of the completion has a zero length,
+            # then it's probably a decomposed unicode character. E.g. caused by
+            # the "\dot" completion. Try to compose again with the previous
+            # character.
+            if wcwidth(text[0]) == 0:
+                if cursor_position + c.start > 0:
+                    char_before = body[c.start - 1]
+                    fixed_text = unicodedata.normalize(
+                        'NFC', char_before + text)
+
+                    # Yield the modified completion instead, if this worked.
+                    if wcwidth(text[0:1]) == 1:
+                        yield Completion(fixed_text, start_position=c.start - offset - 1)
+                        continue
+
+            # TODO: Use Jedi to determine meta_text
+            # (Jedi currently has a bug that results in incorrect information.)
+            # meta_text = ''
+            # yield Completion(m, start_position=start_pos,
+            #                  display_meta=meta_text)
+            display_text = c.text
+
+            adjusted_text = _adjust_completion_text_based_on_context(c.text, body, offset)
+            if c.type == 'function':
+                yield Completion(adjusted_text, start_position=c.start - offset, display=_elide(display_text+'()'), display_meta=c.type+c.signature)
+            else:
+                yield Completion(adjusted_text, start_position=c.start - offset, display=_elide(display_text), display_meta=c.type)
+
+class IPythonPTLexer(Lexer):
+    """
+    Wrapper around PythonLexer and BashLexer.
+    """
+    def __init__(self):
+        l = pygments_lexers
+        self.python_lexer = PygmentsLexer(l.Python3Lexer)
+        self.shell_lexer = PygmentsLexer(l.BashLexer)
+
+        self.magic_lexers = {
+            'HTML': PygmentsLexer(l.HtmlLexer),
+            'html': PygmentsLexer(l.HtmlLexer),
+            'javascript': PygmentsLexer(l.JavascriptLexer),
+            'js': PygmentsLexer(l.JavascriptLexer),
+            'perl': PygmentsLexer(l.PerlLexer),
+            'ruby': PygmentsLexer(l.RubyLexer),
+            'latex': PygmentsLexer(l.TexLexer),
+        }
+
+    def lex_document(self, cli, document):
+        text = document.text.lstrip()
+
+        lexer = self.python_lexer
+
+        if text.startswith('!') or text.startswith('%%bash'):
+            lexer = self.shell_lexer
+
+        elif text.startswith('%%'):
+            for magic, l in self.magic_lexers.items():
+                if text.startswith('%%' + magic):
+                    lexer = l
+                    break
+
+        return lexer.lex_document(cli, document)