def show(s, reduced=True, dot_path=None, pdf_path=None, fmt='pretty'):
"""Generates a graphviz diagram of the AST for the given path. Since this
is mostly debug functionality, there are also options to print various
significant values.
:param s: The regular expression to parse
:param reduced: If True, includes only productions used for generating code
in the diagram. If False, includes all productions in the
diagram. Defaults to True.
:param dot_path: Where to write dot file, if any
:param pdf_path: Where to write PDF file. Requires dot_file to also be set.
:param format: 'pretty' or 'json'
"""
ALLOWED_FORMATS = ('pretty', 'json')
if fmt not in ALLOWED_FORMATS:
raise ValueError('fmt must be one of %r' % ALLOWED_FORMATS)
log.info('dot path: %s' % dot_path)
if fmt == 'pretty':
log.info('Tokens:')
lexer.lexer.input(s)
for tok in iter(lexer.lexer.token, None):
log.info('%r %r' % (tok.type, tok.value))
root = parser.parse(s, (not reduced))
if dot_path:
visualize.ast_dot(root, dot_path)
log.info("Graphviz written to %s" % dot_path)
if pdf_path:
pdf_path = os.path.abspath(pdf_path)
try:
p = subprocess.Popen(
["dot", "-Tpdf", dot_path, "-o", pdf_path],
stderr=subprocess.PIPE,
stdout=subprocess.PIPE)
_, stderr = p.communicate()
if p.returncode != 0:
raise OSError(stderr)
log.info("PDF written to %s" % pdf_path)
except OSError:
log.error("PDF could not be written. Graphviz does not appear"
" to be installed or some other error occurred.")
instr_list = root.generate_instructions()
instr_list.append(instructions.Instruction('match'))
# Print instructions after the AST is drawn in case instruction printing
# fails
program = instructions.serialize(instr_list)
if fmt == 'json':
program = [(opcode_to_cmd[inst[0]].upper(), inst[1], inst[2])
for inst in program]
json.dump(program, sys.stdout)
elif fmt == 'pretty':
log.info("Instructions for VM:")
instructions.prettyprint_program(program)
def parse(s):
"""
Converts a regular expression into bytecode for the VM
:param s: A regular expression
:return: A list of opcode tuples in the form `[(opcode, arg1, arg2)]`
"""
instr_list = parser.parse(s).generate_instructions()
instr_list.append(instructions.Instruction('match'))
return instructions.serialize(instr_list)
