Spreadsheet: Implement a specialised version of printf for formatting

Now all format values will format a single double, cast to the
appropriate types.

Applications/Spreadsheet/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(SOURCES
     Cell.cpp
     CellSyntaxHighlighter.cpp
+    CellType/Format.cpp
     CellType/Identity.cpp
     CellType/Numeric.cpp
     CellType/String.cpp

Applications/Spreadsheet/CellType/Format.cpp

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Format.h"
+#include <AK/PrintfImplementation.h>
+#include <AK/String.h>
+#include <AK/StringBuilder.h>
+
+namespace Spreadsheet {
+
+template<typename T, typename V>
+struct SingleEntryListNext {
+    ALWAYS_INLINE T operator()(V value) const
+    {
+        return (T)value;
+    }
+};
+
+template<typename PutChFunc, typename ArgumentListRefT, template<typename T, typename U = ArgumentListRefT> typename NextArgument>
+struct PrintfImpl : public PrintfImplementation::PrintfImpl<PutChFunc, ArgumentListRefT, NextArgument> {
+    ALWAYS_INLINE PrintfImpl(PutChFunc& putch, char*& bufptr, const int& nwritten)
+        : PrintfImplementation::PrintfImpl<PutChFunc, ArgumentListRefT, NextArgument>(putch, bufptr, nwritten)
+    {
+    }
+
+    // Disallow pointer formats.
+    ALWAYS_INLINE int format_n(const PrintfImplementation::ModifierState&, ArgumentListRefT&) const
+    {
+        return 0;
+    }
+    ALWAYS_INLINE int format_s(const PrintfImplementation::ModifierState&, ArgumentListRefT&) const
+    {
+        return 0;
+    }
+};
+
+String format_double(const char* format, double value)
+{
+    StringBuilder builder;
+    auto putch = [&](auto, auto ch) { builder.append(ch); };
+    printf_internal<decltype(putch), PrintfImpl, double, SingleEntryListNext>(putch, nullptr, format, value);
+
+    return builder.build();
+}
+
+}

Applications/Spreadsheet/CellType/Format.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/Forward.h>
+
+namespace Spreadsheet {
+
+String format_double(const char* format, double value);
+
+}

Applications/Spreadsheet/CellType/Numeric.cpp

@@ -27,6 +27,7 @@
 #include "Numeric.h"
 #include "../Cell.h"
 #include "../Spreadsheet.h"
+#include "Format.h"
 
 namespace Spreadsheet {
 
@@ -46,7 +47,7 @@ String NumericCell::display(Cell& cell, const CellTypeMetadata& metadata) const
     if (metadata.format.is_null())
         string = value.to_string_without_side_effects();
     else
-        string = String::format(metadata.format.characters(), value.to_double(cell.sheet->interpreter())); // FIXME: Somehow make this format less dependent on 'double'.
+        string = format_double(metadata.format.characters(), value.to_double(cell.sheet->interpreter()));
 
     if (metadata.length >= 0)
         return string.substring(0, metadata.length);