def construct(self):
# Accept as a prefix all types that can have a null value
expr = construct(
self.expr,
lambda cls: cls.null_allowed,
'Invalid prefix type for .then: {expr_type}'
)
self.var_expr.set_type(expr.type)
# Create a then-expr specific scope to restrict the span of the "then"
# variable in the debugger.
with PropertyDef.get_scope().new_child() as then_scope:
then_scope.add(self.var_expr.local_var)
then_expr = construct(self.then_expr)
var_expr = construct(self.var_expr)
then_expr = BindingScope(then_expr, [var_expr], scope=then_scope)
# Affect default value to the fallback expression
then_expr, default_expr = expr_or_null(
then_expr, self.default_val,
'Then expression', "function's return type"
)
return Then.Expr(expr, construct(self.var_expr), then_expr,
default_expr, then_scope)
def construct(self):
"""
Construct a resolved expression for this.
:rtype: If.Expr
"""
then, else_then = expr_or_null(self._then, self.else_then,
'If expression', None)
return If.Expr(construct(self.cond, T.Bool), then, else_then,
abstract_expr=self)