def iterator(self, type: Type, values: bool = False) -> "FieldIteratorT":
"""Get an iterator function for a given type, if possible."""
if ismappingtype(type):
iter = _valuescaller if values else _itemscaller
return iter
if isiterabletype(type):
return _iter
fields = self.get_fields(type, as_source=True) or {}
if fields:
func_name = get_defname("iterator", (type, values))
oname = "o"
ctx: dict = {}
with Block(ctx) as main:
with main.f(func_name, Block.p(oname)) as func:
if values:
for f in fields:
func.l(f"{Keyword.YLD} {oname}.{f}")
else:
for f in fields:
func.l(f"{Keyword.YLD} {f!r}, {oname}.{f}")
return main.compile(name=func_name, ns=ctx)
raise TranslatorTypeError(
f"Cannot get iterator for type {type!r}, unable to determine fields."
) from None
def _compile_iterable_translator(self, source: Type, target: Type) -> TranslatorT:
func_name = self._get_name(source, target)
target_name = get_name(target)
oname = "o"
ismapping = ismappingtype(target)
iterator = self.iterator(source, not ismapping)
ctx = {"iterator": iterator, target_name: target}
with Block(ctx) as main:
with main.f(func_name, Block.p(oname)) as func:
retval = f"iterator({oname})"
if not isiteratortype(target):
retval = f"{target_name}({retval})"
func.l(f"{Keyword.RET} {retval}")
return main.compile(name=func_name)
def iterator(
self,
type: Type,
values: bool = False,
relaxed: bool = False,
exclude: Tuple[str, ...] = (),
) -> IteratorT:
"""Get an iterator function for a given type, if possible."""
mapping, iterable, builtin, namedtuple, typicklass = (
ismappingtype(type),
isiterabletype(type),
isbuiltinsubtype(type),
isnamedtuple(type),
istypicklass(type),
)
if mapping:
return _valuescaller if values else _itemscaller
if (iterable, namedtuple, typicklass) == (True, False, False):
return iter if values else enumerate
if (builtin, iterable) == (True, False):
raise TranslatorTypeError(
f"Cannot get iterator for type {type.__name__!r}."
) from None
fields = self.get_fields(type, as_source=True, exclude=exclude) or {}
if not fields and not relaxed:
raise TranslatorTypeError(
f"Cannot get iterator for type {type.__name__!r}, "
f"unable to determine fields."
) from None
func_name = get_defname("iterator", (type, values))
oname = "o"
ctx: dict = {}
with Block(ctx) as main:
with main.f(func_name, Block.p(oname)) as func:
if fields:
if values:
for f in fields:
func.l(f"{Keyword.YLD} {oname}.{f}")
else:
for f in fields:
func.l(f"{Keyword.YLD} {f!r}, {oname}.{f}")
else:
func.l(f"{Keyword.YLD}")
return main.compile(name=func_name, ns=ctx)
def _compile_translator(
self, source: Type, target: Type, exclude: Tuple[str, ...] = ()
) -> TranslatorT:
if isliteral(target):
raise TranslatorTypeError(
f"Cannot translate to literal type: {target!r}. "
) from None
if isliteral(source):
raise TranslatorTypeError(
f"Cannot translate from literal type: {source!r}. "
) from None
# Get the target fields for translation.
target_fields = self.get_fields(target)
if target_fields is None:
if isiterabletype(target):
return self._compile_iterable_translator(source, target)
raise TranslatorTypeError(
f"Cannot translate to type {target!r}. "
f"Unable to determine target fields."
) from None
# Ensure that the target fields are a subset of the source fields.
# We treat the target fields as the parameters for the target,
# so this must be true.
fields = self.get_fields(source, as_source=True, exclude=exclude) or {}
fields_to_pass = {x: fields[x] for x in fields.keys() & target_fields.keys()}
required = self.required_fields(target_fields)
if not required.issubset(fields_to_pass.keys()):
diff = (*(required - fields.keys()),)
raise TranslatorValueError(
f"{source!r} can't be translated to {target!r}. "
f"Source is missing required fields: {diff}."
) from None
protocols = self.resolver.protocols(target)
# Build the translator.
anno_name = get_unique_name(source)
target_name = get_unique_name(target)
func_name = self._get_name(source, target)
oname = "o"
ctx: Dict[str, Any] = {target_name: target, anno_name: source}
with Block(ctx) as main:
with main.f(func_name, Block.p(oname)) as func:
args = ", ".join(
self._iter_field_assigns(fields_to_pass, oname, protocols, ctx)
)
func.l(f"{Keyword.RET} {target_name}({args})")
trans = main.compile(name=func_name, ns=ctx)
return trans
