def visit_If(self, ast_if: If):
if_node = IfNode()
# coord = coordinate(ast_if.col_offset, ast_if.lineno)
# self.set_coordinate(if_node, coord)
# condition
if_node.condition = self.visit(ast_if.test)
# convert pyc true statement to list
if type(ast_if.body) is not list:
ast_if.body = [ast_if.body]
self.parent = if_node.true_stmt
for child in ast_if.body or []:
child_node = self.visit(child)
if child_node:
if type(child_node) is list:
if_node.true_stmt.extend(child_node)
else:
if_node.true_stmt.append(child_node)
# convert pyc false statement to list
if ast_if.orelse:
if type(ast_if.orelse) is not list:
ast_if.orelse = [ast_if.orelse]
self.parent = if_node.false_stmt
for child in ast_if.orelse or []:
child_node = self.visit(child)
if child_node:
if type(child_node) is list:
if_node.false_stmt.extend(child_node)
else:
if_node.false_stmt.append(child_node)
return if_node
def compile_ifnode(self, srcnode, parent):
comparison = get_comparison('{}'.format(srcnode.test))
if_ = If(test=comparison, body=[], orelse=[])
parent.body.append(self.annotate_runtime_errors(if_, srcnode))
for item in srcnode.children:
self._compile(item, if_)
if srcnode.else_:
m = Module(body=[])
for item in srcnode.else_.children:
self._compile(item, m)
if_.orelse = m.body
if if_.body == []:
if_.body = [Pass()]
def compile_choosenode(self, srcnode, parent):
if srcnode.test is None or srcnode.test.strip() == '':
srcnode.test = 'True'
choosevar = self.unique_id('choose')
chooseflag = self.unique_id('chosen')
parent.body.append(self.annotate_runtime_errors(
parse_and_strip(u'{} = False\n'
u'{} = {}\n'.format(chooseflag,
choosevar,
srcnode.test)),
srcnode))
for item in srcnode.children:
if isinstance(item, im.WhenNode):
comparison = get_comparison(u'{} is False and {} == ({})'
.format(chooseflag,
choosevar,
item.test))
if_ = If(test=comparison, body=[], orelse=[])
if_.body.extend(
parse_and_strip('{} = True'.format(chooseflag)))
set_pos(if_, item)
parent.body.append(self.annotate_runtime_errors(if_, srcnode))
for sub in item.children:
self._compile(sub, if_)
elif isinstance(item, im.OtherwiseNode):
comparison = get_comparison('{} is False'.format(chooseflag))
if_ = If(test=comparison, body=[], orelse=[])
set_pos(if_, item)
parent.body.append(if_)
for sub in item.children:
self._compile(sub, if_)
if if_.body == []:
if_.body = [Pass()]
else:
self._compile(item, parent)
def parseIfStatement(parser):
parser.check(lexeme=keywords['IF'])
lineo = parser.currentToken[2]
parser.next(lexeme='(')
parser.next()
predicate = parsePredicate(parser)
parser.check(lexeme=')')
parser.next()
stm = parseStatement(parser)
elsestm = ""
if parser.matchLexeme(keywords['ELSE']):
parser.next()
elsestm = parseStatement(parser)
ifstm = If(predicate, stm, elsestm, lineo=lineo)
return ifstm
def handle_when(self, when, *others):
test, body = when.get_source_expressions()
if others:
if others[0].__class__.__name__ == "When":
orelse = [self.handle_when(*others)]
else:
# Can we ever have other expressions after the default?
orelse = [
Return(value=self.build_expression(others[0]), **self.file)
]
else:
orelse = []
return If(
test=self.build_expression(test),
body=[Return(value=self.build_expression(body), **self.file)],
orelse=orelse,
**self.file,
)
def command(self):
""" c ::=
skip
| x := e
| if b then c1 else c2
| while b do c
"""
if self.current_token.type == '{':
self.eat('{')
c = self.comma_command()
self.eat('}')
return c
if self.current_token.type == 'skip':
self.eat('skip')
return Skip()
if self.current_token.type == 'if':
self.eat('if')
b = self.b_or()
self.eat('then')
c1 = self.comma_command()
self.eat('else')
c2 = self.comma_command()
return If(b, c1, c2)
if self.current_token.type == 'while':
# print("current token:", self.current_token.type, self.current_token.value)
self.eat('while')
# print("current token:", self.current_token.type, self.current_token.value)
b = self.b_or()
# print(b, b.token, b.value)
# print("current token:", self.current_token.type, self.current_token.value)
self.eat('do')
# print("current token:", self.current_token.type, self.current_token.value)
c = self.command()
# print(c)
# print("current token:", self.current_token.type, self.current_token.value)
return While(b, c)
if self.current_token.type == VAR:
x = Var(self.current_token.value)
self.eat(VAR)
self.eat(':=')
e = self.aexp()
return Assign(x, e)
def register_binding(withstmt, mode, kind):
assert mode in ("block", "expr")
assert kind in ("barename", "template")
ctxmanager = withstmt.items[0].context_expr
optvars = withstmt.items[0].optional_vars
if not optvars:
assert False, "'with {}:': expected an as-part".format(
mode) # pragma: no cover
if type(optvars) is not Name:
assert False, "'with {}:': expected exactly one name in the as-part".format(
mode) # pragma: no cover
name = optvars.id
if name in names_seen:
assert False, "duplicate '{}'; as-parts in the same let_syntax block must be unique".format(
name) # pragma: no cover
if kind == "template":
_, args = _analyze_lhs(
ctxmanager
) # syntactic limitation, can't place formal parameter list on the as-part
else: # kind == "barename":
args = []
if mode == "block":
value = If(
test=Num(n=1), # TODO: Python 3.8+: ast.Constant, no ast.Num
body=withstmt.body,
orelse=[],
lineno=stmt.lineno,
col_offset=stmt.col_offset)
else: # mode == "expr":
if len(withstmt.body) != 1:
assert False, "'with expr:' expected a one-item body (use a do[] if need more)" # pragma: no cover
theexpr = withstmt.body[0]
if type(theexpr) is not Expr:
assert False, "'with expr:' expected an expression body, got a statement" # pragma: no cover
value = theexpr.value # discard Expr wrapper in definition
names_seen.add(name)
target = templates if args else barenames
target.append((name, args, value, mode))
def visit_If(self, node: ast.If) -> str:
body_vars: Set[str] = set(
[get_id(v) for v in node.scopes[-1].body_vars])
orelse_vars: Set[str] = set(
[get_id(v) for v in node.scopes[-1].orelse_vars])
node.common_vars = body_vars.intersection(orelse_vars)
body: str = "\n".join([
self.indent(self.visit(child), level=node.level + 1)
for child in node.body
])
orelse: str = "\n".join([
self.indent(self.visit(child), level=node.level + 1)
for child in node.orelse
])
test: str = self.visit(node.test)
if node.orelse:
orelse = self.indent(f"else {{\n{orelse}\n}}", level=node.level)
else:
orelse = ""
return f"if {test} {{\n{body}\n}}\n{orelse}"
def p_if_statement(self, p):
'''if_statement : IF LPAREN logical_expression RPAREN block_statement %prec IFX'''
p[0] = If(p[3], p[5], None)
