def __expression():
return sor(
Grammar.template,
Grammar.link,
Grammar.headings,
Grammar.epsilon,
Grammar.linebreak,
)
def link(parser):
"""Link grammar
Wikimedia EBNF
start link = "[[";
end link = "]]";
internal link = start link, full pagename, ["|", label], end link,
---
Internal
pagename := ε
expression := template
| link
| ε
link := '[[' pagename, { expression } ']]'
The link contain the page name, and 0 or more repetitions of the expression ["|", label]. That is simplified with
an expression that can by any one of the wikimedia non-terminals (text, template, link for now)
Watch out left recursion (a link can contain a link)
TODO add external link too, https://en.wikipedia.org/wiki/Help:Link#External_links
:param parser:
:return:
"""
# expression = sor(expect(Link.end), rep(sor(Grammar.epsilon, Grammar.template, Grammar.link), Link.end))
def extractor(arr):
return (lambda _, c, children, __: (c, children))(*arr)
result = pipe(
parser,
seq(
expect(Link.start), Grammar.epsilon,
rep(
sor(Grammar.epsilon,
Grammar.template,
Grammar.link,
Grammar.formatting,
Grammar.linebreak,
at_least_one=True), Link.end), expect(Link.end)),
extractor)
if result:
(content, nodes) = result
node = p.LinkNode(p.LinkP(content.value))
for n in nodes:
node.add(n)
return node
return None
def heading(start, end):
return seq(
expect(start),
rep(
sor(Grammar.epsilon,
Grammar.template,
Grammar.link,
Grammar.formatting,
at_least_one=True), end),
expect(end),
# expect(LineBreak.start))
Grammar.linebreak)
def headings(parser):
""" Heading
Wikimedia EBNF
header end = [whitespace], line break;
header6 = line break, "======", [whitespace], text, [whitespace], "======", header end;
header5 = line break, "=====", [whitespace], text, [whitespace], "=====", header end;
header4 = line break, "====", [whitespace], text, [whitespace], "====", header end;
header3 = line break, "===", [whitespace], text, [whitespace], "===", header end;
header2 = line break, "==", [whitespace], text, [whitespace], "==", header end;
---
Internal EBNF
header6 = "======", text, "======", linebreak;
header5 = "=====", text, "=====", linebreak;
header4 = "====", text, "====", linebreak;
header3 = "===", text, "===", linebreak;
header2 = "==", text, "==", linebreak;
"""
precedence = [Heading6, Heading5, Heading4, Heading3, Heading]
def extractor(r):
_, arr, __, linebreak = r
return arr
def heading(start, end):
return seq(
expect(start),
rep(
sor(Grammar.epsilon,
Grammar.template,
Grammar.link,
Grammar.formatting,
at_least_one=True), end),
expect(end),
# expect(LineBreak.start))
Grammar.linebreak)
try:
result = pipe(parser,
sor(*[heading(i.start, i.end) for i in precedence]),
extractor)
except ParseError as e:
return Grammar.epsilon(parser)
# return p.TextP()
if result:
nodes = result
node = p.HeadingNode('Heading')
node.children = nodes
return node
return None
def formatting(parser):
match = [ItalicAndBold, Bold, Italic]
def format(start, end):
return seq(expect(start),
rep(sor(Grammar.epsilon, Grammar.link), end),
expect(end))
def extractor(r):
_, arr, __ = r
return arr[0]
try:
result = pipe(parser, sor(*[format(i.start, i.end)
for i in match]), extractor)
if result:
return p.Node(p.FormattingP(result.value))
return None
except ParseError as e:
raise e
def expression(self):
"""
Wikimedia primary expression
ε : = text
expression := template
| heading_2
| link
| ε
:param parser:
:return:
"""
# sor(*Grammar.rules.values())
return sor(
self.template,
self.link,
self.headings,
self.epsilon,
self.linebreak,
self.list,
# self.formatting
)
def list_item(parser):
def extractor(r):
_, arr, _ = r
return arr
result = pipe(
parser,
seq(
expect(List.start),
rep(
sor(Grammar.epsilon,
Grammar.template,
Grammar.link,
Grammar.headings,
Grammar.list,
at_least_one=True), LineBreak.end),
expect(LineBreak.end, False)), extractor)
if result:
# return result
node = p.Node(None)
node.children = result
return node
return None
def format(start, end):
return seq(expect(start),
rep(sor(Grammar.epsilon, Grammar.link), end),
expect(end))