def _check_link(source, target, length, start):
""" check inline link, link reference or link definition
link :: <!>?<lb><whitespace>*<link_name>whitespace*<rb>[link_definition|link_url]
link_name :: span_element
"""
index, is_img = start, False
if source[index] == '!':
is_img = True
index += 1
if index >= length or source[index] != '[':
return start
index += 1
(index, content) = helper.forward_until(source, index, ']')
brackets = helper.elimate_whitespace_around(content)
index += 1
jumps = helper.elimate_leading_whitespace(source[index:], '[')
index += jumps
if index >= length or source[index] not in ':[(':
return start
if source[index] == ':':
new_index = _split_link_definition(source, target, length, index + 1,
brackets)
else:
new_index = _split_link(source, target, length, index,
(brackets, is_img))
return new_index if new_index > index else start
def _check_emphasis(source, target, length, start):
""" emphasis :: [bold_emphasis|italic_emphasis]
bold_emphasis :: [*|_][2]<whitespace>*<span_element><whitespace>*[*|_][2]
italic_emphasis :: [*|_]<whitespace>*<span_element><whitespace>*[*|_]
"""
if source[start] not in '_*':
return start
symbol = source[start]
index, emp_type, content = start, 'italic', []
if index + 1 < length and source[index + 1] == symbol:
index += 1
emp_type = 'bold'
index += 1
(index, content) = helper.forward_until(source, index, symbol)
if index >= length:
return start
content = helper.elimate_whitespace_around(content)
if emp_type == 'bold' and (index + 1 >= length
or source[index + 1] != symbol):
target.append({'span_type': 'text', 'content': [symbol]})
emp_type = 'italic'
target.append({'span_type': emp_type, 'content': parse_span(content, [])})
if emp_type == 'italic':
index += 1
else:
index += 2
return index
def _split_link(source, target, length, start, prev_info):
"""
link_url :: [regular_link_url|reference_link_url]
regular_link_url :: <lp><whitespace>*<url_and_title><whitespace>*<rp>
reference_link_url :: <whitespace>*<lb><whitespace>*<url_and_title><whitespace>*<rb>
url_and_title :: <text_element><whitespace>+<text_element>*
"""
index = start
inner, is_img = prev_info
link_type = 'inline' if source[index] == '(' else 'refer'
end = ')' if link_type == 'inline' else ']'
index += 1
(index, content) = helper.forward_until(source, index, end)
if index >= length:
return start
content = helper.elimate_whitespace_around(content)
if link_type == 'inline':
_check_inline_link(target, content, inner, is_img)
else:
target.append({
'span_type': 'ref_link',
'inner': parse_span(inner, []),
'content': content,
'is_img': is_img
})
return index + 1
def _check_strike_out(source, target, length, start):
""" strike_out :: <~>[2]<span_element><~>[2]
"""
if source[:2] != '~~':
return start
index = start + 2
(index, content) = helper.forward_until(source, index, '~~')
if index + 1 >= length:
return start
content = helper.elimate_whitespace_around(content)
target.append({
'span_type': 'strike_out',
'content': parse_span(content, [])
})
return index + 2
def _check_script(source, target, length, start):
"""
script :: [~|^]<whitespace>*<span_element><whitespace>*[~|^]
"""
if source[start] not in '~^':
return start
symbol = source[start]
index, content = start, []
script_type = 'super_script' if source[start] == '^' else 'sub_script'
index += 1
(index, content) = helper.forward_until(source, index, symbol)
if index >= length:
return start
content = helper.elimate_whitespace_around(content)
target.append({
'span_type': script_type,
'content': parse_span(content, [])
})
return index + 1