def visit_DecompFor(self, node):
if (isinstance(node.iter, L.Name) and node.iter.id in self.rels):
if len(node.vars) != 1:
raise L.TransformationError(
'Singleton unwrapping requires all DecompFor loops '
'over relation to have exactly one target variable')
return L.For(node.vars[0], node.iter, node.body)
return node
def get_code(self, cl, bindenv, body):
vars = self.lhs_vars(cl)
assert_unique(vars)
mask = L.mask_from_bounds(vars, bindenv)
if L.mask_is_allbound(mask):
comparison = L.Compare(L.Name(cl.elem), L.In(), L.Name(cl.set))
code = (L.If(comparison, body, ()), )
needs_typecheck = True
elif mask == L.mask('bu'):
code = (L.For(cl.elem, L.Name(cl.set), body), )
needs_typecheck = True
else:
code = super().get_code(cl, bindenv, body)
needs_typecheck = False
if needs_typecheck and self.use_typecheck:
code = (L.If(L.IsSet(L.Name(cl.set)), code, ()), )
return code
def get_code(self, cl, bindenv, body):
vars = self.lhs_vars(cl)
rel = self.rhs_rel(cl)
assert_unique(vars)
mask = L.mask_from_bounds(vars, bindenv)
if L.mask_is_allbound(mask):
comparison = L.Compare(L.tuplify(vars), L.In(), L.Name(rel))
code = (L.If(comparison, body, ()), )
elif L.mask_is_allunbound(mask):
code = (L.DecompFor(vars, L.Name(rel), body), )
else:
bvars, uvars = L.split_by_mask(mask, vars)
lookup = L.ImgLookup(L.Name(rel), mask, bvars)
# Optimize in the case where there's only one unbound.
if len(uvars) == 1:
code = (L.For(uvars[0], L.Unwrap(lookup), body), )
else:
code = (L.DecompFor(uvars, lookup, body), )
return code
