def container_of(inner, arg, *, type, min_length=0, flatten=False, **kwargs):
if not is_iterable(arg):
raise IbisTypeError('Argument must be a sequence')
if len(arg) < min_length:
raise IbisTypeError(
f'Arg must have at least {min_length} number of elements')
if flatten:
arg = flatten_iterable(arg)
return type(inner(item, **kwargs) for item in arg)
def one_of(inners, arg, **kwargs):
"""At least one of the inner validators must pass"""
for inner in inners:
with suppress(IbisTypeError, ValueError):
return inner(arg, **kwargs)
raise IbisTypeError("argument passes none of the following rules: "
f"{', '.join(map(repr, inners))}")
def cast(source: str | DataType, target: str | DataType, **kwargs) -> DataType:
"""Attempts to implicitly cast from source dtype to target dtype"""
source, target = dtype(source), dtype(target)
if not castable(source, target, **kwargs):
raise IbisTypeError(
f'Datatype {source} cannot be implicitly casted to {target}'
)
return target
def higher_precedence(left: DataType, right: DataType) -> DataType:
if castable(left, right, upcast=True):
return right
elif castable(right, left, upcast=True):
return left
raise IbisTypeError(
f'Cannot compute precedence for {left} and {right} types'
)
def from_string(value: str) -> DataType:
try:
return parse(value)
except SyntaxError:
raise IbisTypeError(f'{value!r} cannot be parsed as a datatype')
def default(value, **kwargs) -> DataType:
raise IbisTypeError(f'Value {value!r} is not a valid datatype')
def instance_of(klasses, arg, **kwargs):
"""Require that a value has a particular Python type."""
if not isinstance(arg, klasses):
raise IbisTypeError(f'Given argument with type {type(arg)} '
f'is not an instance of {klasses}')
return arg