skeleton for uinvert

Author: samukweku

src/core/expr/funary/uinvert.cc

@@ -0,0 +1,88 @@
+//------------------------------------------------------------------------------
+// Copyright 2023 H2O.ai
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//------------------------------------------------------------------------------
+#include "column/const.h"
+#include "documentation.h"
+#include "expr/fexpr_column.h"
+#include "expr/funary/umaker.h"
+#include "expr/eval_context.h"
+#include "expr/workframe.h"
+#include "python/xargs.h"
+namespace dt
+{
+  namespace expr
+  {
+
+    FExpr_UINVERT::FExpr_UINVERT(ptrExpr &&arg) : arg_(std::move(arg))
+    {}
+
+    std::string FExpr_UINVERT::repr() const
+    {
+      std::string out = "uinvert";
+      out += '(';
+      out += arg_->repr();
+      out += ')';
+      return out;
+    }
+
+    static Column make_isna_col(Column &&col)
+    {
+      switch (stype) {
+        case SType::VOID:    return umaker_ptr(new umaker_copy());
+        case SType::BOOL:    return umaker1<int8_t, int8_t>::make(op_invert_bool, SType::AUTO, SType::BOOL);
+        case SType::INT8:    return _uinvert<int8_t>();
+        case SType::INT16:   return _uinvert<int16_t>();
+        case SType::INT32:   return _uinvert<int32_t>();
+        case SType::INT64:   return _uinvert<int64_t>();
+        default:
+        throw TypeError() << "Cannot apply unary `operator ~` to a column with "
+                            "stype `" << stype << "`";
+    }
+    }
+
+    Workframe FExpr_UINVERT::evaluate_n(EvalContext &ctx) const
+    {
+      Workframe wf = arg_->evaluate_n(ctx);
+
+      for (size_t i = 0; i < wf.ncols(); ++i)
+      {
+        Column coli = make_isna_col(wf.retrieve_column(i));
+        wf.replace_column(i, std::move(coli));
+      }
+
+      return wf;
+    }
+
+    static py::oobj pyfn_isna(const py::XArgs &args)
+    {
+      auto uinvert = args[0].to_oobj();
+      return PyFExpr::make(new FExpr_ISNA(as_fexpr(uinvert)));
+    }
+
+    DECLARE_PYFN(&pyfn_isna)
+        ->name("uinvert")
+        ->docs(doc_math_isna)
+        ->arg_names({"cols"})
+        ->n_positional_args(1)
+        ->n_required_args(1);
+
+  }
+} // dt::expr