Package nltk :: Package draw :: Module cfg :: Class CFGEditor

type CFGEditor

object --+
         |
        CFGEditor

A dialog window for creating and editing context free grammars. CFGEditor places the following restrictions on what CFGs can be edited:

All nonterminals must be strings consisting of word characters.
All terminals must be strings consisting of word characters and space characters.

Instance Methods

[hide private]

__init__(self, parent, cfg=None, set_cfg_callback=None)

source code

_init_startframe(self)

source code

_init_buttons(self)

source code

_init_bindings(self)

source code

_init_prodframe(self)

source code

_clear_tags(self, linenum)
Remove all tags (except arrow and sel) from the given line of the text widget used for editing the productions. source code

_check_analyze(self, *e)
Check if we've moved to a new line.

source code

_replace_arrows(self, *e)
Replace any '->' text strings with arrows (char \256, in symbol font). source code

_analyze_token(self, match, linenum)
Given a line number and a regexp match for a token on that line, colorize the token.

source code

_init_nonterminal_tag(self, tag, foreground='blue') source code

_analyze_line(self, linenum)
Colorize a given line.

source code

_mark_error(self, linenum, line)
Mark the location of an error in a line.

source code

_analyze(self, *e)
Replace -> with arrows, and colorize the entire buffer. source code

_parse_productions(self)
Parse the current contents of the textwidget buffer, to create a list of productions.

source code

_destroy(self, *e)

source code

_ok(self, *e)

source code

_apply(self, *e)

source code

_reset(self, *e)

source code

_cancel(self, *e)

source code

_help(self, *e)

source code

Class Variables

[hide private]

ARROW = '\xde'

_LHS_RE = re.compile(r'(^\s*\w+\s*)(->|(\xde))')

_ARROW_RE = re.compile(r'\s*(->|(\xde))\s*')

_PRODUCTION_RE = re.compile(r'(^\s*\w+\s*)(->|(\xde))\s*((\w+|...

_TOKEN_RE = re.compile(r'\w+|->|\'[\w ]+\'|"[\w ]+"|(\xde)')

_BOLD = ('helvetica', -12, 'bold')

Method Details

[hide private]

init(self, parent, cfg=None, set_cfg_callback=None)
(Constructor)

source code

Overrides: object.__init__: (inherited documentation)

_check_analyze(self, *e)

source code

Check if we've moved to a new line. If we have, then remove all colorization from the line we moved to, and re-colorize the line that we moved from.

_replace_arrows(self, *e)

source code

Replace any '->' text strings with arrows (char \256, in symbol font). This searches the whole buffer, but is fast enough to be done anytime they press '>'.

_analyze_token(self, match, linenum)

source code

Given a line number and a regexp match for a token on that line, colorize the token. Note that the regexp match gives us the token's text, start index (on the line), and end index (on the line).

Class Variable Details

[hide private]

_PRODUCTION_RE

Value:

re.compile(r'(^\s*\w+\s*)(->|(\xde))\s*((\w+|\'[\w ]*\'|"[\w ]*"|\|)\s
*)*$')

type CFGEditor

__init__(self, parent, cfg=None, set_cfg_callback=None) (Constructor)

_check_analyze(self, *e)

_replace_arrows(self, *e)

_analyze_token(self, match, linenum)

_PRODUCTION_RE

init(self, parent, cfg=None, set_cfg_callback=None)
(Constructor)