def eta_expand_tuple(
path: qlast.Path,
stype: s_types.Tuple,
*,
ctx: context.ContextLevel,
) -> qlast.Expr:
"""η-expansion of tuples
η-expansion of tuple types is straightforward and traditional:
EXPAND(tuple<t, s>, p) = (EXPAND(t, p.0), EXPAND(s, p.1))
is the case for pairs. n-ary and named cases are generalized in the
obvious way.
The one exception is that the expansion of the empty tuple type is
`p` and not `()`, to ensure that the path appears in the output.
"""
if not stype.get_subtypes(ctx.env.schema):
return path
els = [
qlast.TupleElement(
name=qlast.ObjectRef(name=name),
val=eta_expand(astutils.extend_path(path, name), subtype, ctx=ctx),
) for name, subtype in stype.iter_subtypes(ctx.env.schema)
]
if stype.is_named(ctx.env.schema):
return qlast.NamedTuple(elements=els)
else:
return qlast.Tuple(elements=[el.val for el in els])
def visit_Tuple(self, node):
if node.named:
result = qlast.NamedTuple(elements=[
qlast.TupleElement(name=el.name, val=self.visit(el.val))
for el in node.elements
])
else:
result = qlast.Tuple(
elements=[self.visit(e.val) for e in node.elements])
return result
def reduce_LPAREN_NamedTupleElementList_COMMA_RPAREN(self, *kids):
self.val = qlast.NamedTuple(elements=kids[1].val)
