def visit_Compare(self, n: ast35.Compare) -> Node:
operators = [self.from_comp_operator(o) for o in n.ops]
operands = self.visit_list([n.left] + n.comparators)
return ComparisonExpr(operators, operands)
def visit_Compare(self, n: ast27.Compare) -> ComparisonExpr:
operators = [self.from_comp_operator(o) for o in n.ops]
operands = self.translate_expr_list([n.left] + n.comparators)
e = ComparisonExpr(operators, operands)
return self.set_line(e, n)
def visit_comparison_expr(self, node: ComparisonExpr) -> Node:
new = ComparisonExpr(node.operators, self.nodes(node.operands))
new.method_types = [self.optional_type(t) for t in node.method_types]
return new
def transform_comparison_expr(builder: IRBuilder, e: ComparisonExpr) -> Value:
# x in (...)/[...]
# x not in (...)/[...]
first_op = e.operators[0]
if (first_op in ['in', 'not in']
and len(e.operators) == 1
and isinstance(e.operands[1], (TupleExpr, ListExpr))):
items = e.operands[1].items
n_items = len(items)
# x in y -> x == y[0] or ... or x == y[n]
# x not in y -> x != y[0] and ... and x != y[n]
# 16 is arbitrarily chosen to limit code size
if 1 < n_items < 16:
if e.operators[0] == 'in':
bin_op = 'or'
cmp_op = '=='
else:
bin_op = 'and'
cmp_op = '!='
lhs = e.operands[0]
mypy_file = builder.graph['builtins'].tree
assert mypy_file is not None
bool_type = Instance(cast(TypeInfo, mypy_file.names['bool'].node), [])
exprs = []
for item in items:
expr = ComparisonExpr([cmp_op], [lhs, item])
builder.types[expr] = bool_type
exprs.append(expr)
or_expr: Expression = exprs.pop(0)
for expr in exprs:
or_expr = OpExpr(bin_op, or_expr, expr)
builder.types[or_expr] = bool_type
return builder.accept(or_expr)
# x in [y]/(y) -> x == y
# x not in [y]/(y) -> x != y
elif n_items == 1:
if e.operators[0] == 'in':
cmp_op = '=='
else:
cmp_op = '!='
e.operators = [cmp_op]
e.operands[1] = items[0]
# x in []/() -> False
# x not in []/() -> True
elif n_items == 0:
if e.operators[0] == 'in':
return builder.false()
else:
return builder.true()
if first_op in ('is', 'is not') and len(e.operators) == 1:
right = e.operands[1]
if isinstance(right, NameExpr) and right.fullname == 'builtins.None':
# Special case 'is None' / 'is not None'.
return translate_is_none(builder, e.operands[0], negated=first_op != 'is')
# TODO: Don't produce an expression when used in conditional context
# All of the trickiness here is due to support for chained conditionals
# (`e1 < e2 > e3`, etc). `e1 < e2 > e3` is approximately equivalent to
# `e1 < e2 and e2 > e3` except that `e2` is only evaluated once.
expr_type = builder.node_type(e)
# go(i, prev) generates code for `ei opi e{i+1} op{i+1} ... en`,
# assuming that prev contains the value of `ei`.
def go(i: int, prev: Value) -> Value:
if i == len(e.operators) - 1:
return transform_basic_comparison(
builder, e.operators[i], prev, builder.accept(e.operands[i + 1]), e.line)
next = builder.accept(e.operands[i + 1])
return builder.builder.shortcircuit_helper(
'and', expr_type,
lambda: transform_basic_comparison(
builder, e.operators[i], prev, next, e.line),
lambda: go(i + 1, next),
e.line)
return go(0, builder.accept(e.operands[0]))
def visit_comparison_expr(self, node: ComparisonExpr) -> Node:
new = ComparisonExpr(node.operators, self.nodes(node.operands))
new.method_types = [self.optional_type(t) for t in node.method_types]
return new
def visit_Compare(self, n):
operators = [self.from_comp_operator(o) for o in n.ops]
operands = self.visit([n.left] + n.comparators)
return ComparisonExpr(operators, operands)