330 lines
13 KiB
Python
Executable File
330 lines
13 KiB
Python
Executable File
# -*- coding: utf-8 -*-
|
|
# lexer.py
|
|
# Copyright (C) 2006, 2007, 2008 Michael Bayer mike_mp@zzzcomputing.com
|
|
#
|
|
# This module is part of Mako and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""provides the Lexer class for parsing template strings into parse trees."""
|
|
|
|
import re, codecs
|
|
from mako import parsetree, exceptions
|
|
from mako.pygen import adjust_whitespace
|
|
|
|
_regexp_cache = {}
|
|
|
|
class Lexer(object):
|
|
def __init__(self, text, filename=None, disable_unicode=False, input_encoding=None, preprocessor=None):
|
|
self.text = text
|
|
self.filename = filename
|
|
self.template = parsetree.TemplateNode(self.filename)
|
|
self.matched_lineno = 1
|
|
self.matched_charpos = 0
|
|
self.lineno = 1
|
|
self.match_position = 0
|
|
self.tag = []
|
|
self.control_line = []
|
|
self.disable_unicode = disable_unicode
|
|
self.encoding = input_encoding
|
|
if preprocessor is None:
|
|
self.preprocessor = []
|
|
elif not hasattr(preprocessor, '__iter__'):
|
|
self.preprocessor = [preprocessor]
|
|
else:
|
|
self.preprocessor = preprocessor
|
|
|
|
exception_kwargs = property(lambda self:{'source':self.text, 'lineno':self.matched_lineno, 'pos':self.matched_charpos, 'filename':self.filename})
|
|
|
|
def match(self, regexp, flags=None):
|
|
"""match the given regular expression string and flags to the current text position.
|
|
|
|
if a match occurs, update the current text and line position."""
|
|
mp = self.match_position
|
|
try:
|
|
reg = _regexp_cache[(regexp, flags)]
|
|
except KeyError:
|
|
if flags:
|
|
reg = re.compile(regexp, flags)
|
|
else:
|
|
reg = re.compile(regexp)
|
|
_regexp_cache[(regexp, flags)] = reg
|
|
|
|
match = reg.match(self.text, self.match_position)
|
|
if match:
|
|
(start, end) = match.span()
|
|
if end == start:
|
|
self.match_position = end + 1
|
|
else:
|
|
self.match_position = end
|
|
self.matched_lineno = self.lineno
|
|
lines = re.findall(r"\n", self.text[mp:self.match_position])
|
|
cp = mp - 1
|
|
while (cp >= 0 and cp<self.textlength and self.text[cp] != '\n'):
|
|
cp -=1
|
|
self.matched_charpos = mp - cp
|
|
self.lineno += len(lines)
|
|
#print "MATCHED:", match.group(0), "LINE START:", self.matched_lineno, "LINE END:", self.lineno
|
|
#print "MATCH:", regexp, "\n", self.text[mp : mp + 15], (match and "TRUE" or "FALSE")
|
|
return match
|
|
|
|
def parse_until_text(self, *text):
|
|
startpos = self.match_position
|
|
while True:
|
|
match = self.match(r'#.*\n')
|
|
if match:
|
|
continue
|
|
match = self.match(r'(\"\"\"|\'\'\'|\"|\')')
|
|
if match:
|
|
m = self.match(r'.*?%s' % match.group(1), re.S)
|
|
if not m:
|
|
raise exceptions.SyntaxException("Unmatched '%s'" % match.group(1), **self.exception_kwargs)
|
|
else:
|
|
match = self.match(r'(%s)' % r'|'.join(text))
|
|
if match:
|
|
return (self.text[startpos:self.match_position-len(match.group(1))], match.group(1))
|
|
else:
|
|
match = self.match(r".*?(?=\"|\'|#|%s)" % r'|'.join(text), re.S)
|
|
if not match:
|
|
raise exceptions.SyntaxException("Expected: %s" % ','.join(text), **self.exception_kwargs)
|
|
|
|
def append_node(self, nodecls, *args, **kwargs):
|
|
kwargs.setdefault('source', self.text)
|
|
kwargs.setdefault('lineno', self.matched_lineno)
|
|
kwargs.setdefault('pos', self.matched_charpos)
|
|
kwargs['filename'] = self.filename
|
|
node = nodecls(*args, **kwargs)
|
|
if len(self.tag):
|
|
self.tag[-1].nodes.append(node)
|
|
else:
|
|
self.template.nodes.append(node)
|
|
if isinstance(node, parsetree.Tag):
|
|
if len(self.tag):
|
|
node.parent = self.tag[-1]
|
|
self.tag.append(node)
|
|
elif isinstance(node, parsetree.ControlLine):
|
|
if node.isend:
|
|
self.control_line.pop()
|
|
elif node.is_primary:
|
|
self.control_line.append(node)
|
|
elif len(self.control_line) and not self.control_line[-1].is_ternary(node.keyword):
|
|
raise exceptions.SyntaxException("Keyword '%s' not a legal ternary for keyword '%s'" % (node.keyword, self.control_line[-1].keyword), **self.exception_kwargs)
|
|
|
|
def escape_code(self, text):
|
|
if not self.disable_unicode and self.encoding:
|
|
return text.encode('ascii', 'backslashreplace')
|
|
else:
|
|
return text
|
|
|
|
def parse(self):
|
|
for preproc in self.preprocessor:
|
|
self.text = preproc(self.text)
|
|
if not isinstance(self.text, unicode) and self.text.startswith(codecs.BOM_UTF8):
|
|
self.text = self.text[len(codecs.BOM_UTF8):]
|
|
parsed_encoding = 'utf-8'
|
|
me = self.match_encoding()
|
|
if me is not None and me != 'utf-8':
|
|
raise exceptions.CompileException("Found utf-8 BOM in file, with conflicting magic encoding comment of '%s'" % me, self.text.decode('utf-8', 'ignore'), 0, 0, self.filename)
|
|
else:
|
|
parsed_encoding = self.match_encoding()
|
|
if parsed_encoding:
|
|
self.encoding = parsed_encoding
|
|
if not self.disable_unicode and not isinstance(self.text, unicode):
|
|
if self.encoding:
|
|
try:
|
|
self.text = self.text.decode(self.encoding)
|
|
except UnicodeDecodeError, e:
|
|
raise exceptions.CompileException("Unicode decode operation of encoding '%s' failed" % self.encoding, self.text.decode('utf-8', 'ignore'), 0, 0, self.filename)
|
|
else:
|
|
try:
|
|
self.text = self.text.decode()
|
|
except UnicodeDecodeError, e:
|
|
raise exceptions.CompileException("Could not read template using encoding of 'ascii'. Did you forget a magic encoding comment?", self.text.decode('utf-8', 'ignore'), 0, 0, self.filename)
|
|
|
|
self.textlength = len(self.text)
|
|
|
|
while (True):
|
|
if self.match_position > self.textlength:
|
|
break
|
|
|
|
if self.match_end():
|
|
break
|
|
if self.match_expression():
|
|
continue
|
|
if self.match_control_line():
|
|
continue
|
|
if self.match_comment():
|
|
continue
|
|
if self.match_tag_start():
|
|
continue
|
|
if self.match_tag_end():
|
|
continue
|
|
if self.match_python_block():
|
|
continue
|
|
if self.match_text():
|
|
continue
|
|
|
|
if self.match_position > self.textlength:
|
|
break
|
|
raise exceptions.CompileException("assertion failed")
|
|
|
|
if len(self.tag):
|
|
raise exceptions.SyntaxException("Unclosed tag: <%%%s>" % self.tag[-1].keyword, **self.exception_kwargs)
|
|
if len(self.control_line):
|
|
raise exceptions.SyntaxException("Unterminated control keyword: '%s'" % self.control_line[-1].keyword, self.text, self.control_line[-1].lineno, self.control_line[-1].pos, self.filename)
|
|
return self.template
|
|
|
|
def match_encoding(self):
|
|
match = self.match(r'#.*coding[:=]\s*([-\w.]+).*\r?\n')
|
|
if match:
|
|
return match.group(1)
|
|
else:
|
|
return None
|
|
|
|
def match_tag_start(self):
|
|
match = self.match(r'''
|
|
\<% # opening tag
|
|
|
|
([\w\.\:]+) # keyword
|
|
|
|
((?:\s+\w+|=|".*?"|'.*?')*) # attrname, = sign, string expression
|
|
|
|
\s* # more whitespace
|
|
|
|
(/)?> # closing
|
|
|
|
''',
|
|
|
|
re.I | re.S | re.X)
|
|
|
|
if match:
|
|
(keyword, attr, isend) = (match.group(1).lower(), match.group(2), match.group(3))
|
|
self.keyword = keyword
|
|
attributes = {}
|
|
if attr:
|
|
for att in re.findall(r"\s*(\w+)\s*=\s*(?:'([^']*)'|\"([^\"]*)\")", attr):
|
|
(key, val1, val2) = att
|
|
text = val1 or val2
|
|
text = text.replace('\r\n', '\n')
|
|
attributes[key] = self.escape_code(text)
|
|
self.append_node(parsetree.Tag, keyword, attributes)
|
|
if isend:
|
|
self.tag.pop()
|
|
else:
|
|
if keyword == 'text':
|
|
match = self.match(r'(.*?)(?=\</%text>)', re.S)
|
|
if not match:
|
|
raise exceptions.SyntaxException("Unclosed tag: <%%%s>" % self.tag[-1].keyword, **self.exception_kwargs)
|
|
self.append_node(parsetree.Text, match.group(1))
|
|
return self.match_tag_end()
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_tag_end(self):
|
|
match = self.match(r'\</%[\t ]*(.+?)[\t ]*>')
|
|
if match:
|
|
if not len(self.tag):
|
|
raise exceptions.SyntaxException("Closing tag without opening tag: </%%%s>" % match.group(1), **self.exception_kwargs)
|
|
elif self.tag[-1].keyword != match.group(1):
|
|
raise exceptions.SyntaxException("Closing tag </%%%s> does not match tag: <%%%s>" % (match.group(1), self.tag[-1].keyword), **self.exception_kwargs)
|
|
self.tag.pop()
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_end(self):
|
|
match = self.match(r'\Z', re.S)
|
|
if match:
|
|
string = match.group()
|
|
if string:
|
|
return string
|
|
else:
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_text(self):
|
|
match = self.match(r"""
|
|
(.*?) # anything, followed by:
|
|
(
|
|
(?<=\n)(?=[ \t]*(?=%|\#\#)) # an eval or line-based comment preceded by a consumed \n and whitespace
|
|
|
|
|
(?=\${) # an expression
|
|
|
|
|
(?=\#\*) # multiline comment
|
|
|
|
|
(?=</?[%&]) # a substitution or block or call start or end
|
|
# - don't consume
|
|
|
|
|
(\\\r?\n) # an escaped newline - throw away
|
|
|
|
|
\Z # end of string
|
|
)""", re.X | re.S)
|
|
|
|
if match:
|
|
text = match.group(1)
|
|
self.append_node(parsetree.Text, text)
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_python_block(self):
|
|
match = self.match(r"<%(!)?")
|
|
if match:
|
|
(line, pos) = (self.matched_lineno, self.matched_charpos)
|
|
(text, end) = self.parse_until_text(r'%>')
|
|
text = adjust_whitespace(text) + "\n" # the trailing newline helps compiler.parse() not complain about indentation
|
|
self.append_node(parsetree.Code, self.escape_code(text), match.group(1)=='!', lineno=line, pos=pos)
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_expression(self):
|
|
match = self.match(r"\${")
|
|
if match:
|
|
(line, pos) = (self.matched_lineno, self.matched_charpos)
|
|
(text, end) = self.parse_until_text(r'\|', r'}')
|
|
if end == '|':
|
|
(escapes, end) = self.parse_until_text(r'}')
|
|
else:
|
|
escapes = ""
|
|
text = text.replace('\r\n', '\n')
|
|
self.append_node(parsetree.Expression, self.escape_code(text), escapes.strip(), lineno=line, pos=pos)
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_control_line(self):
|
|
match = self.match(r"(?<=^)[\t ]*(%|##)[\t ]*((?:(?:\\r?\n)|[^\r\n])*)(?:\r?\n|\Z)", re.M)
|
|
if match:
|
|
operator = match.group(1)
|
|
text = match.group(2)
|
|
if operator == '%':
|
|
m2 = re.match(r'(end)?(\w+)\s*(.*)', text)
|
|
if not m2:
|
|
raise exceptions.SyntaxException("Invalid control line: '%s'" % text, **self.exception_kwargs)
|
|
(isend, keyword) = m2.group(1, 2)
|
|
isend = (isend is not None)
|
|
|
|
if isend:
|
|
if not len(self.control_line):
|
|
raise exceptions.SyntaxException("No starting keyword '%s' for '%s'" % (keyword, text), **self.exception_kwargs)
|
|
elif self.control_line[-1].keyword != keyword:
|
|
raise exceptions.SyntaxException("Keyword '%s' doesn't match keyword '%s'" % (text, self.control_line[-1].keyword), **self.exception_kwargs)
|
|
self.append_node(parsetree.ControlLine, keyword, isend, self.escape_code(text))
|
|
else:
|
|
self.append_node(parsetree.Comment, text)
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def match_comment(self):
|
|
"""matches the multiline version of a comment"""
|
|
match = self.match(r"<%doc>(.*?)</%doc>", re.S)
|
|
if match:
|
|
self.append_node(parsetree.Comment, match.group(1))
|
|
return True
|
|
else:
|
|
return False
|
|
|