def _cast_expr(ql_type: qlast.TypeName, ir_expr: irast.Base, *,
source_context: parsing.ParserContext,
ctx: context.ContextLevel) -> irast.Base:
try:
orig_type = irutils.infer_type(ir_expr, ctx.schema)
except errors.EdgeQLError:
# It is possible that the source expression is unresolved
# if the expr is an empty set (or a coalesce of empty sets).
orig_type = None
if isinstance(orig_type, s_types.Tuple):
# For tuple-to-tuple casts we generate a new tuple
# to simplify things on sqlgen side.
new_type = typegen.ql_typeref_to_type(ql_type, ctx=ctx)
if not isinstance(new_type, s_types.Tuple):
raise errors.EdgeQLError(f'cannot cast tuple to {new_type.name}',
context=source_context)
if len(orig_type.element_types) != len(new_type.element_types):
raise errors.EdgeQLError(
f'cannot cast to {new_type.name}: '
f'number of elements is not the same',
context=source_context)
new_names = list(new_type.element_types)
elements = []
for i, n in enumerate(orig_type.element_types):
val = setgen.generated_set(irast.TupleIndirection(expr=ir_expr,
name=n),
ctx=ctx)
val.path_id = irutils.tuple_indirection_path_id(
ir_expr.path_id, n, orig_type.element_types[n])
val_type = irutils.infer_type(val, ctx.schema)
new_el_name = new_names[i]
if val_type != new_type.element_types[new_el_name]:
# Element cast
val = _cast_expr(ql_type.subtypes[i],
val,
ctx=ctx,
source_context=source_context)
elements.append(irast.TupleElement(name=new_el_name, val=val))
return irast.Tuple(named=new_type.named, elements=elements)
elif isinstance(ir_expr, irast.EmptySet):
# For the common case of casting an empty set, we simply
# generate a new EmptySet node of the requested type.
scls = typegen.ql_typeref_to_type(ql_type, ctx=ctx)
return irutils.new_empty_set(ctx.schema,
scls=scls,
alias=ir_expr.path_id.target.name.name)
else:
typ = typegen.ql_typeref_to_ir_typeref(ql_type, ctx=ctx)
return setgen.ensure_set(irast.TypeCast(expr=ir_expr, type=typ),
ctx=ctx)
def make_tuple(
elements: typing.List[irast.TupleElement], *,
named: bool,
ctx: context.ContextLevel) -> irast.Tuple:
tup = irast.Tuple(elements=elements, named=named)
tup.stype = inference.infer_type(tup, env=ctx.env)
return tup
def compile_Tuple(expr: qlast.Base, *,
ctx: context.ContextLevel) -> irast.Base:
elements = []
for i, el in enumerate(expr.elements):
element = irast.TupleElement(name=str(i),
val=dispatch.compile(el, ctx=ctx))
elements.append(element)
return setgen.generated_set(irast.Tuple(elements=elements), ctx=ctx)
def compile_NamedTuple(expr: qlast.Base, *,
ctx: context.ContextLevel) -> irast.Base:
elements = [dispatch.compile(e, ctx=ctx) for e in expr.elements]
return setgen.generated_set(irast.Tuple(elements=elements, named=True),
ctx=ctx)
