Fix #2049 (get the current completed argument)

A command argument can now be completed even if it isn’t the last
one in the input.

- Add a new method Input.new_completion
    Almost like the old auto_completion method, except taht it takes
    another argument: argument_position, which is the argument to be
    completed.
- Methods using the old completion method still work
- All completion methods in poezio now use the new one if necessary
- Further details can be found in the docstring of new_completion

1 files changed, 303 insertions, 0 deletions

diff --git a/src/shlex.py b/src/shlex.py
new file mode 100644
index 00000000..87a241ed
--- /dev/null
+++ b/src/shlex.py
@@ -0,0 +1,303 @@
+"""
+A lexical analyzer class for simple shell-like syntaxes.
+
+Tweaked for the specific needs of parsing poezio input.
+
+"""
+
+# Module and documentation by Eric S. Raymond, 21 Dec 1998
+# Input stacking and error message cleanup added by ESR, March 2000
+# push_source() and pop_source() made explicit by ESR, January 2001.
+# Posix compliance, split(), string arguments, and
+# iterator interface by Gustavo Niemeyer, April 2003.
+
+import os
+import re
+import sys
+from collections import deque
+
+from io import StringIO
+
+__all__ = ["shlex", "split", "quote"]
+
+class shlex:
+    """
+    A custom version of the shlex in the stdlib to yield more information
+    """
+    def __init__(self, instream=None, infile=None, posix=True):
+        if isinstance(instream, str):
+            instream = StringIO(instream)
+        if instream is not None:
+            self.instream = instream
+            self.infile = infile
+        else:
+            self.instream = sys.stdin
+            self.infile = None
+        self.posix = posix
+        self.eof = ''
+        self.commenters = ''
+        self.wordchars = ('abcdfeghijklmnopqrstuvwxyz'
+                          'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_')
+        if self.posix:
+            self.wordchars += ('ßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ'
+                               'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞ')
+        self.whitespace = ' \t\r\n'
+        self.whitespace_split = True
+        self.quotes = '"'
+        self.escape = '\\'
+        self.escapedquotes = '"'
+        self.state = ' '
+        self.pushback = deque()
+        self.lineno = 1
+        self.debug = 0
+        self.token = ''
+        self.filestack = deque()
+        self.source = None
+        if self.debug:
+            print('shlex: reading from %s, line %d' \
+                  % (self.instream, self.lineno))
+
+    def push_token(self, tok):
+        "Push a token onto the stack popped by the get_token method"
+        if self.debug >= 1:
+            print("shlex: pushing token " + repr(tok))
+        self.pushback.appendleft(tok)
+
+    def push_source(self, newstream, newfile=None):
+        "Push an input source onto the lexer's input source stack."
+        if isinstance(newstream, str):
+            newstream = StringIO(newstream)
+        self.filestack.appendleft((self.infile, self.instream, self.lineno))
+        self.infile = newfile
+        self.instream = newstream
+        self.lineno = 1
+        if self.debug:
+            if newfile is not None:
+                print('shlex: pushing to file %s' % (self.infile,))
+            else:
+                print('shlex: pushing to stream %s' % (self.instream,))
+
+    def pop_source(self):
+        "Pop the input source stack."
+        self.instream.close()
+        (self.infile, self.instream, self.lineno) = self.filestack.popleft()
+        if self.debug:
+            print('shlex: popping to %s, line %d' \
+                  % (self.instream, self.lineno))
+        self.state = ' '
+
+    def get_token(self):
+        "Get a token from the input stream (or from stack if it's nonempty)"
+        if self.pushback:
+            tok = self.pushback.popleft()
+            if self.debug >= 1:
+                print("shlex: popping token " + repr(tok))
+            return tok
+        # No pushback.  Get a token.
+        start, end,  raw = self.read_token()
+        # Handle inclusions
+        # Maybe we got EOF instead?
+        while raw == self.eof:
+            if not self.filestack:
+                return self.eof
+            else:
+                self.pop_source()
+                start, end, raw = self.get_token()
+        # Neither inclusion nor EOF
+        if self.debug >= 1:
+            if raw != self.eof:
+                print("shlex: token=" + repr(raw))
+            else:
+                print("shlex: token=EOF")
+        return start, end, raw
+
+    def read_token(self):
+        quoted = False
+        escapedstate = ' '
+        token_start = 0
+        token_end = -1
+        while True:
+            nextchar = self.instream.read(1)
+            if nextchar == '\n':
+                self.lineno = self.lineno + 1
+            if self.debug >= 3:
+                print("shlex: in state", repr(self.state), \
+                      "I see character:", repr(nextchar))
+            if self.state is None:
+                self.token = ''        # past end of file
+                token_end = self.instream.tell()
+                break
+            elif self.state == ' ':
+                if not nextchar:
+                    self.state = None  # end of file
+                    token_end = self.instream.tell()
+                    break
+                elif nextchar in self.whitespace:
+                    if self.debug >= 2:
+                        print("shlex: I see whitespace in whitespace state")
+                    if self.token or (self.posix and quoted):
+                        token_end = self.instream.tell() - 1
+                        break   # emit current token
+                    else:
+                        continue
+                elif nextchar in self.commenters:
+                    self.instream.readline()
+                    self.lineno = self.lineno + 1
+                elif self.posix and nextchar in self.escape:
+                    token_start = self.instream.tell() - 1
+                    escapedstate = 'a'
+                    self.state = nextchar
+                elif nextchar in self.wordchars:
+                    token_start = self.instream.tell() - 1
+                    self.token = nextchar
+                    self.state = 'a'
+                elif nextchar in self.quotes:
+                    token_start = self.instream.tell() - 1
+                    self.state = nextchar
+                elif self.whitespace_split:
+                    token_start = self.instream.tell() - 1
+                    self.token = nextchar
+                    self.state = 'a'
+                else:
+                    token_start = self.instream.tell() - 1
+                    self.token = nextchar
+                    if self.token or (self.posix and quoted):
+                        token_end = self.instream.tell() - 1
+                        break   # emit current token
+                    else:
+                        continue
+            elif self.state in self.quotes:
+                quoted = True
+                if not nextchar:      # end of file
+                    if self.debug >= 2:
+                        print("shlex: I see EOF in quotes state")
+                    # XXX what error should be raised here?
+                    token_end = self.instream.tell()
+                    break
+                if nextchar == self.state:
+                    if not self.posix:
+                        self.token = self.token + nextchar
+                        self.state = ' '
+                        token_end = self.instream.tell()
+                        break
+                    else:
+                        self.state = 'a'
+                elif self.posix and nextchar in self.escape and \
+                     self.state in self.escapedquotes:
+                    escapedstate = self.state
+                    self.state = nextchar
+                else:
+                    self.token = self.token + nextchar
+            elif self.state in self.escape:
+                if not nextchar:      # end of file
+                    if self.debug >= 2:
+                        print("shlex: I see EOF in escape state")
+                    # XXX what error should be raised here?
+                    token_end = self.instream.tell()
+                    break
+                # In posix shells, only the quote itself or the escape
+                # character may be escaped within quotes.
+                if escapedstate in self.quotes and \
+                   nextchar != self.state and nextchar != escapedstate:
+                    self.token = self.token + self.state
+                self.token = self.token + nextchar
+                self.state = escapedstate
+            elif self.state == 'a':
+                if not nextchar:
+                    self.state = None   # end of file
+                    token_end = self.instream.tell()
+                    break
+                elif nextchar in self.whitespace:
+                    if self.debug >= 2:
+                        print("shlex: I see whitespace in word state")
+                    self.state = ' '
+                    if self.token or (self.posix and quoted):
+                        token_end = self.instream.tell() - 1
+                        break   # emit current token
+                    else:
+                        continue
+                elif self.posix and nextchar in self.quotes:
+                    self.state = nextchar
+                elif self.posix and nextchar in self.escape:
+                    escapedstate = 'a'
+                    self.state = nextchar
+                elif nextchar in self.wordchars or nextchar in self.quotes \
+                    or self.whitespace_split:
+                    self.token = self.token + nextchar
+                else:
+                    self.pushback.appendleft(nextchar)
+                    if self.debug >= 2:
+                        print("shlex: I see punctuation in word state")
+                    self.state = ' '
+                    if self.token:
+                        token_end = self.instream.tell()
+                        break   # emit current token
+                    else:
+                        continue
+        result = self.token
+        self.token = ''
+        if self.posix and not quoted and result == '':
+            result = None
+        if self.debug > 1:
+            if result:
+                print("shlex: raw token=" + repr(result))
+            else:
+                print("shlex: raw token=EOF")
+        return (token_start, token_end, result)
+
+    def sourcehook(self, newfile):
+        "Hook called on a filename to be sourced."
+        if newfile[0] == '"':
+            newfile = newfile[1:-1]
+        # This implements cpp-like semantics for relative-path inclusion.
+        if isinstance(self.infile, str) and not os.path.isabs(newfile):
+            newfile = os.path.join(os.path.dirname(self.infile), newfile)
+        return (newfile, open(newfile, "r"))
+
+    def error_leader(self, infile=None, lineno=None):
+        "Emit a C-compiler-like, Emacs-friendly error-message leader."
+        if infile is None:
+            infile = self.infile
+        if lineno is None:
+            lineno = self.lineno
+        return "\"%s\", line %d: " % (infile, lineno)
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        token = self.get_token()
+        if token and token[0] == self.eof:
+            raise StopIteration
+        return token
+
+def split(s, comments=False, posix=True):
+    lex = shlex(s, posix=posix)
+    lex.whitespace_split = True
+    if not comments:
+        lex.commenters = ''
+    return list(lex)
+
+
+_find_unsafe = re.compile(r'[^\w@%+=:,./-]', re.ASCII).search
+
+def quote(s):
+    """Return a shell-escaped version of the string *s*."""
+    if not s:
+        return "''"
+    if _find_unsafe(s) is None:
+        return s
+
+    # use single quotes, and put single quotes into double quotes
+    # the string $'b is then quoted as '$'"'"'b'
+    return "'" + s.replace("'", "'\"'\"'") + "'"
+
+
+if __name__ == '__main__':
+    lexer = shlex(instream=sys.argv[1])
+    while 1:
+        tt = lexer.get_token()
+        if tt:
+            print("Token: " + repr(tt))
+        else:
+            break