AK+Format: Do some housekeeping in the format implementation.

11 files changed, 464 insertions, 623 deletions

diff --git a/AK/Format.cpp b/AK/Format.cpp
index e9211cc570..5331b7621b 100644
--- a/AK/Format.cpp
+++ b/AK/Format.cpp
@@ -26,174 +26,97 @@
 
 #include <AK/Format.h>
 #include <AK/GenericLexer.h>
-#include <AK/PrintfImplementation.h>
 #include <AK/String.h>
 #include <AK/StringBuilder.h>
 #include <ctype.h>
 
+namespace AK {
+
 namespace {
 
 constexpr size_t use_next_index = NumericLimits<size_t>::max();
 
-struct FormatSpecifier {
-    StringView flags;
-    size_t index;
-};
-
-class FormatStringParser : public GenericLexer {
-public:
-    explicit FormatStringParser(StringView input)
-        : GenericLexer(input)
-    {
-    }
-
-    StringView consume_literal()
-    {
-        const auto begin = tell();
-
-        while (!is_eof()) {
-            if (consume_specific("{{"))
-                continue;
-
-            if (consume_specific("}}"))
-                continue;
-
-            if (next_is(is_any_of("{}")))
-                return m_input.substring_view(begin, tell() - begin);
-
-            consume();
-        }
-
-        return m_input.substring_view(begin);
-    }
-
-    bool consume_number(size_t& value)
-    {
-        value = 0;
+// The worst case is that we have the largest 64-bit value formatted as binary number, this would take
+// 65 bytes. Choosing a larger power of two won't hurt and is a bit of mitigation against out-of-bounds accesses.
+inline size_t convert_unsigned_to_string(u64 value, Array<u8, 128>& buffer, u8 base, bool upper_case)
+{
+    ASSERT(base >= 2 && base <= 16);
 
-        bool consumed_at_least_one = false;
-        while (next_is(isdigit)) {
-            value *= 10;
-            value += consume() - '0';
-            consumed_at_least_one = true;
-        }
+    static constexpr const char* lowercase_lookup = "0123456789abcdef";
+    static constexpr const char* uppercase_lookup = "0123456789ABCDEF";
 
-        return consumed_at_least_one;
+    if (value == 0) {
+        buffer[0] = '0';
+        return 1;
     }
 
-    bool consume_specifier(FormatSpecifier& specifier)
-    {
-        ASSERT(!next_is('}'));
-
-        if (!consume_specific('{'))
-            return false;
-
-        if (!consume_number(specifier.index))
-            specifier.index = use_next_index;
-
-        if (consume_specific(':')) {
-            const auto begin = tell();
-
-            size_t level = 1;
-            while (level > 0) {
-                ASSERT(!is_eof());
-
-                if (consume_specific('{')) {
-                    ++level;
-                    continue;
-                }
-
-                if (consume_specific('}')) {
-                    --level;
-                    continue;
-                }
-
-                consume();
-            }
-
-            specifier.flags = m_input.substring_view(begin, tell() - begin - 1);
-        } else {
-            if (!consume_specific('}'))
-                ASSERT_NOT_REACHED();
-
-            specifier.flags = "";
-        }
+    size_t used = 0;
+    while (value > 0) {
+        if (upper_case)
+            buffer[used++] = uppercase_lookup[value % base];
+        else
+            buffer[used++] = lowercase_lookup[value % base];
 
-        return true;
+        value /= base;
     }
 
-    bool consume_replacement_field(size_t& index)
-    {
-        if (!consume_specific('{'))
-            return false;
-
-        if (!consume_number(index))
-            index = use_next_index;
+    for (size_t i = 0; i < used / 2; ++i)
+        swap(buffer[i], buffer[used - i - 1]);
 
-        if (!consume_specific('}'))
-            ASSERT_NOT_REACHED();
-
-        return true;
-    }
-};
-
-void write_escaped_literal(StringBuilder& builder, StringView literal)
-{
-    for (size_t idx = 0; idx < literal.length(); ++idx) {
-        builder.append(literal[idx]);
-        if (literal[idx] == '{' || literal[idx] == '}')
-            ++idx;
-    }
+    return used;
 }
 
-void vformat_impl(StringBuilder& builder, FormatStringParser& parser, AK::FormatterContext& context)
+void vformat_impl(TypeErasedFormatParams& params, FormatBuilder& builder, FormatParser& parser)
 {
     const auto literal = parser.consume_literal();
-    write_escaped_literal(builder, literal);
+    builder.put_literal(literal);
 
-    FormatSpecifier specifier;
+    FormatParser::FormatSpecifier specifier;
     if (!parser.consume_specifier(specifier)) {
         ASSERT(parser.is_eof());
         return;
     }
 
     if (specifier.index == use_next_index)
-        specifier.index = context.take_next_index();
-
-    ASSERT(specifier.index < context.parameter_count());
+        specifier.index = params.take_next_index();
 
-    context.set_flags(specifier.flags);
+    auto& parameter = params.parameters().at(specifier.index);
 
-    auto& parameter = context.parameter_at(specifier.index);
-    parameter.formatter(builder, parameter.value, context);
+    FormatParser argparser { specifier.flags };
+    parameter.formatter(params, builder, argparser, parameter.value);
 
-    vformat_impl(builder, parser, context);
+    vformat_impl(params, builder, parser);
 }
 
-size_t decode_value(size_t value, AK::FormatterContext& context)
+} // namespace AK::{anonymous}
+
+size_t TypeErasedFormatParams::decode(size_t value, size_t default_value)
 {
-    if (value == AK::StandardFormatter::value_from_next_arg)
-        value = AK::StandardFormatter::value_from_arg + context.take_next_index();
+    if (value == StandardFormatter::value_not_set)
+        return default_value;
 
-    if (value >= AK::StandardFormatter::value_from_arg) {
-        const auto parameter = context.parameter_at(value - AK::StandardFormatter::value_from_arg);
+    if (value == StandardFormatter::value_from_next_arg)
+        value = StandardFormatter::value_from_arg + take_next_index();
+
+    if (value >= StandardFormatter::value_from_arg) {
+        const auto parameter = parameters().at(value - StandardFormatter::value_from_arg);
 
         Optional<i64> svalue;
-        if (parameter.type == AK::TypeErasedParameter::Type::UInt8)
+        if (parameter.type == TypeErasedParameter::Type::UInt8)
             value = *reinterpret_cast<const u8*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::UInt16)
+        else if (parameter.type == TypeErasedParameter::Type::UInt16)
             value = *reinterpret_cast<const u16*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::UInt32)
+        else if (parameter.type == TypeErasedParameter::Type::UInt32)
             value = *reinterpret_cast<const u32*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::UInt64)
+        else if (parameter.type == TypeErasedParameter::Type::UInt64)
             value = *reinterpret_cast<const u64*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::Int8)
+        else if (parameter.type == TypeErasedParameter::Type::Int8)
             svalue = *reinterpret_cast<const i8*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::Int16)
+        else if (parameter.type == TypeErasedParameter::Type::Int16)
             svalue = *reinterpret_cast<const i16*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::Int32)
+        else if (parameter.type == TypeErasedParameter::Type::Int32)
             svalue = *reinterpret_cast<const i32*>(parameter.value);
-        else if (parameter.type == AK::TypeErasedParameter::Type::Int64)
+        else if (parameter.type == TypeErasedParameter::Type::Int64)
             svalue = *reinterpret_cast<const i64*>(parameter.value);
         else
             ASSERT_NOT_REACHED();
@@ -207,47 +130,274 @@ size_t decode_value(size_t value, AK::FormatterContext& context)
     return value;
 }
 
-} // namespace
+FormatParser::FormatParser(StringView input)
+    : GenericLexer(input)
+{
+}
+StringView FormatParser::consume_literal()
+{
+    const auto begin = tell();
 
-namespace AK {
+    while (!is_eof()) {
+        if (consume_specific("{{"))
+            continue;
+
+        if (consume_specific("}}"))
+            continue;
+
+        if (next_is(is_any_of("{}")))
+            return m_input.substring_view(begin, tell() - begin);
+
+        consume();
+    }
+
+    return m_input.substring_view(begin);
+}
+bool FormatParser::consume_number(size_t& value)
+{
+    value = 0;
+
+    bool consumed_at_least_one = false;
+    while (next_is(isdigit)) {
+        value *= 10;
+        value += consume() - '0';
+        consumed_at_least_one = true;
+    }
+
+    return consumed_at_least_one;
+}
+bool FormatParser::consume_specifier(FormatSpecifier& specifier)
+{
+    ASSERT(!next_is('}'));
+
+    if (!consume_specific('{'))
+        return false;
+
+    if (!consume_number(specifier.index))
+        specifier.index = use_next_index;
+
+    if (consume_specific(':')) {
+        const auto begin = tell();
+
+        size_t level = 1;
+        while (level > 0) {
+            ASSERT(!is_eof());
+
+            if (consume_specific('{')) {
+                ++level;
+                continue;
+            }
+
+            if (consume_specific('}')) {
+                --level;
+                continue;
+            }
+
+            consume();
+        }
+
+        specifier.flags = m_input.substring_view(begin, tell() - begin - 1);
+    } else {
+        if (!consume_specific('}'))
+            ASSERT_NOT_REACHED();
+
+        specifier.flags = "";
+    }
+
+    return true;
+}
+bool FormatParser::consume_replacement_field(size_t& index)
+{
+    if (!consume_specific('{'))
+        return false;
+
+    if (!consume_number(index))
+        index = use_next_index;
+
+    if (!consume_specific('}'))
+        ASSERT_NOT_REACHED();
+
+    return true;
+}
 
-void vformat(StringBuilder& builder, StringView fmtstr, Span<const TypeErasedParameter> parameters)
+void FormatBuilder::put_padding(char fill, size_t amount)
 {
-    FormatStringParser parser { fmtstr };
-    FormatterContext context { parameters };
-    vformat_impl(builder, parser, context);
+    for (size_t i = 0; i < amount; ++i)
+        m_builder.append(fill);
 }
-void vformat(const LogStream& stream, StringView fmtstr, Span<const TypeErasedParameter> parameters)
+void FormatBuilder::put_literal(StringView value)
+{
+    for (size_t i = 0; i < value.length(); ++i) {
+        m_builder.append(value[i]);
+        if (value[i] == '{' || value[i] == '}')
+            ++i;
+    }
+}
+void FormatBuilder::put_string(
+    StringView value,
+    Align align,
+    size_t min_width,
+    size_t max_width,
+    char fill)
+{
+    const auto used_by_string = min(max_width, value.length());
+    const auto used_by_padding = max(min_width, used_by_string) - used_by_string;
+
+    if (used_by_string < value.length())
+        value = value.substring_view(0, used_by_string);
+
+    if (align == Align::Left || align == Align::Default) {
+        m_builder.append(value);
+        put_padding(fill, used_by_padding);
+    } else if (align == Align::Center) {
+        const auto used_by_left_padding = used_by_padding / 2;
+        const auto used_by_right_padding = ceil_div<size_t, size_t>(used_by_padding, 2);
+
+        put_padding(fill, used_by_left_padding);
+        m_builder.append(value);
+        put_padding(fill, used_by_right_padding);
+    } else if (align == Align::Right) {
+        put_padding(fill, used_by_padding);
+        m_builder.append(value);
+    }
+}
+void FormatBuilder::put_u64(
+    u64 value,
+    u8 base,
+    bool prefix,
+    bool upper_case,
+    bool zero_pad,
+    Align align,
+    size_t min_width,
+    char fill,
+    SignMode sign_mode,
+    bool is_negative)
+{
+    Array<u8, 128> buffer;
+
+    const auto used_by_digits = convert_unsigned_to_string(value, buffer, base, upper_case);
+
+    auto used_by_prefix = sign_mode == SignMode::OnlyIfNeeded ? static_cast<size_t>(is_negative) : 1;
+    if (prefix) {
+        if (base == 8)
+            used_by_prefix += 1;
+        else if (base == 16)
+            used_by_prefix += 2;
+        else if (base == 2)
+            used_by_prefix += 2;
+    }
+
+    const auto used_by_field = used_by_prefix + used_by_digits;
+    const auto used_by_padding = max(used_by_field, min_width) - used_by_field;
+
+    const auto put_prefix = [&]() {
+        if (is_negative)
+            m_builder.append('-');
+        else if (sign_mode == SignMode::Always)
+            m_builder.append('+');
+        else if (sign_mode == SignMode::Reserved)
+            m_builder.append(' ');
+
+        if (prefix) {
+            if (base == 2) {
+                if (upper_case)
+                    m_builder.append("0B");
+                else
+                    m_builder.append("0b");
+            } else if (base == 8) {
+                m_builder.append("0");
+            } else if (base == 16) {
+                if (upper_case)
+                    m_builder.append("0X");
+                else
+                    m_builder.append("0x");
+            }
+        }
+    };
+    const auto put_digits = [&]() {
+        for (size_t i = 0; i < used_by_digits; ++i)
+            m_builder.append(buffer[i]);
+    };
+
+    if (align == Align::Left) {
+        const auto used_by_right_padding = used_by_padding;
+
+        put_prefix();
+        put_digits();
+        put_padding(fill, used_by_right_padding);
+    } else if (align == Align::Center) {
+        const auto used_by_left_padding = used_by_padding / 2;
+        const auto used_by_right_padding = ceil_div<size_t, size_t>(used_by_padding, 2);
+
+        put_padding(fill, used_by_left_padding);
+        put_prefix();
+        put_digits();
+        put_padding(fill, used_by_right_padding);
+    } else if (align == Align::Right || align == Align::Default) {
+        const auto used_by_left_padding = used_by_padding;
+
+        if (zero_pad) {
+            put_prefix();
+            put_padding('0', used_by_left_padding);
+            put_digits();
+        } else {
+            put_padding(fill, used_by_left_padding);
+            put_prefix();
+            put_digits();
+        }
+    }
+}
+void FormatBuilder::put_i64(
+    i64 value,
+    u8 base,
+    bool prefix,
+    bool upper_case,
+    bool zero_pad,
+    Align align,
+    size_t min_width,
+    char fill,
+    SignMode sign_mode)
+{
+    const auto is_negative = value < 0;
+    value = is_negative ? -value : value;
+
+    put_u64(static_cast<size_t>(value), base, prefix, upper_case, zero_pad, align, min_width, fill, sign_mode, is_negative);
+}
+
+void vformat(StringBuilder& builder, StringView fmtstr, TypeErasedFormatParams params)
+{
+    FormatBuilder fmtbuilder { builder };
+    FormatParser parser { fmtstr };
+
+    vformat_impl(params, fmtbuilder, parser);
+}
+void vformat(const LogStream& stream, StringView fmtstr, TypeErasedFormatParams params)
 {
     StringBuilder builder;
-    FormatStringParser parser { fmtstr };
-    FormatterContext context { parameters };
-    vformat_impl(builder, parser, context);
+    vformat(builder, fmtstr, params);
     stream << builder.to_string();
 }
 
-void StandardFormatter::parse(FormatterContext& context)
+void StandardFormatter::parse(TypeErasedFormatParams& params, FormatParser& parser)
 {
-    FormatStringParser parser { context.flags() };
-
     if (StringView { "<^>" }.contains(parser.peek(1))) {
         ASSERT(!parser.next_is(is_any_of("{}")));
         m_fill = parser.consume();
     }
 
     if (parser.consume_specific('<'))
-        m_align = Align::Left;
+        m_align = FormatBuilder::Align::Left;
     else if (parser.consume_specific('^'))
-        m_align = Align::Center;
+        m_align = FormatBuilder::Align::Center;
     else if (parser.consume_specific('>'))
-        m_align = Align::Right;
+        m_align = FormatBuilder::Align::Right;
 
     if (parser.consume_specific('-'))
-        m_sign = Sign::NegativeOnly;
+        m_sign_mode = FormatBuilder::SignMode::OnlyIfNeeded;
     else if (parser.consume_specific('+'))
-        m_sign = Sign::PositiveAndNegative;
+        m_sign_mode = FormatBuilder::SignMode::Always;
     else if (parser.consume_specific(' '))
-        m_sign = Sign::ReserveSpace;
+        m_sign_mode = FormatBuilder::SignMode::Reserved;
 
     if (parser.consume_specific('#'))
         m_alternative_form = true;
@@ -257,7 +407,7 @@ void StandardFormatter::parse(FormatterContext& context)
 
     if (size_t index = 0; parser.consume_replacement_field(index)) {
         if (index == use_next_index)
-            index = context.take_next_index();
+            index = params.take_next_index();
 
         m_width = value_from_arg + index;
     } else if (size_t width = 0; parser.consume_number(width)) {
@@ -267,7 +417,7 @@ void StandardFormatter::parse(FormatterContext& context)
     if (parser.consume_specific('.')) {
         if (size_t index = 0; parser.consume_replacement_field(index)) {
             if (index == use_next_index)
-                index = context.take_next_index();
+                index = params.take_next_index();
 
             m_precision = value_from_arg + index;
         } else if (size_t precision = 0; parser.consume_number(precision)) {
@@ -300,9 +450,9 @@ void StandardFormatter::parse(FormatterContext& context)
     ASSERT(parser.is_eof());
 }
 
-void Formatter<StringView>::format(StringBuilder& builder, StringView value, FormatterContext& context)
+void Formatter<StringView>::format(TypeErasedFormatParams& params, FormatBuilder& builder, StringView value)
 {
-    if (m_sign != Sign::Default)
+    if (m_sign_mode != FormatBuilder::SignMode::Default)
         ASSERT_NOT_REACHED();
     if (m_alternative_form)
         ASSERT_NOT_REACHED();
@@ -313,64 +463,32 @@ void Formatter<StringView>::format(StringBuilder& builder, StringView value, For
     if (m_width != value_not_set && m_precision != value_not_set)
         ASSERT_NOT_REACHED();
 
-    if (m_align == Align::Default)
-        m_align = Align::Left;
-
-    const auto width = decode_value(m_width, context);
-    const auto precision = decode_value(m_precision, context);
-
-    const auto put_padding = [&](size_t amount, char fill) {
-        for (size_t i = 0; i < amount; ++i)
-            builder.append(fill);
-    };
-    const auto put_bytes = [&](ReadonlyBytes bytes) {
-        for (size_t i = 0; i < bytes.size(); ++i)
-            builder.append(static_cast<char>(bytes[i]));
-    };
-
-    auto used_by_string = value.length();
-    if (precision != value_not_set)
-        used_by_string = min(used_by_string, precision);
-
-    const auto used_by_padding = width < used_by_string ? 0 : width - used_by_string;
+    const auto width = params.decode(m_width);
+    const auto precision = params.decode(m_precision, NumericLimits<size_t>::max());
 
-    if (m_align == Align::Left) {
-        const auto used_by_right_padding = used_by_padding;
+    builder.put_string(value, m_align, width, precision, m_fill);
+}
 
-        put_bytes(value.bytes().trim(used_by_string));
-        put_padding(used_by_right_padding, m_fill);
-        return;
-    }
-    if (m_align == Align::Center) {
-        const auto used_by_left_padding = used_by_padding / 2;
-        const auto used_by_right_padding = ceil_div<size_t, size_t>(used_by_padding, 2);
+template<typename T>
+void Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type>::format(TypeErasedFormatParams& params, FormatBuilder& builder, T value)
+{
+    if (m_mode == Mode::Character) {
+        // FIXME: We just support ASCII for now, in the future maybe unicode?
+        ASSERT(value >= 0 && value <= 127);
 
-        put_padding(used_by_left_padding, m_fill);
-        put_bytes(value.bytes().trim(used_by_string));
-        put_padding(used_by_right_padding, m_fill);
-        return;
-    }
-    if (m_align == Align::Right) {
-        const auto used_by_left_padding = used_by_padding;
+        m_mode = Mode::String;
 
-        put_padding(used_by_left_padding, m_fill);
-        put_bytes(value.bytes().trim(used_by_string));
-        return;
+        Formatter<StringView> formatter { *this };
+        return formatter.format(params, builder, StringView { reinterpret_cast<const char*>(&value), 1 });
     }
 
-    ASSERT_NOT_REACHED();
-}
-
-template<typename T>
-void Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type>::format(StringBuilder& builder, T value, FormatterContext& context)
-{
-    if (m_precision != value_not_set)
+    if (m_precision != NumericLimits<size_t>::max())
         ASSERT_NOT_REACHED();
 
     if (m_mode == Mode::Pointer) {
-        if (m_sign != Sign::Default)
+        if (m_sign_mode != FormatBuilder::SignMode::Default)
             ASSERT_NOT_REACHED();
-        if (m_align != Align::Default)
+        if (m_align != FormatBuilder::Align::Default)
             ASSERT_NOT_REACHED();
         if (m_alternative_form)
             ASSERT_NOT_REACHED();
@@ -399,91 +517,26 @@ void Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type>::format(StringB
     } else if (m_mode == Mode::HexadecimalUppercase) {
         base = 16;
         upper_case = true;
-    } else if (m_mode == Mode::Character) {
-        // special case
     } else {
         ASSERT_NOT_REACHED();
     }
 
-    const auto width = decode_value(m_width, context);
-
-    const auto put_padding = [&](size_t amount, char fill) {
-        for (size_t i = 0; i < amount; ++i)
-            builder.append(fill);
-    };
-
-    if (m_mode == Mode::Character) {
-        // FIXME: We just support ASCII for now, in the future maybe unicode?
-        ASSERT(value >= 0 && value <= 127);
-
-        const size_t used_by_value = 1;
-        const auto used_by_padding = width < used_by_value ? 0 : width - used_by_value;
-
-        if (m_align == Align::Left || m_align == Align::Default) {
-            const auto used_by_right_padding = used_by_padding;
-
-            builder.append(static_cast<char>(value));
-            put_padding(used_by_right_padding, m_fill);
-            return;
-        }
-        if (m_align == Align::Center) {
-            const auto used_by_left_padding = used_by_padding / 2;
-            const auto used_by_right_padding = ceil_div<size_t, size_t>(used_by_padding, 2);
-
-            put_padding(used_by_left_padding, m_fill);
-            builder.append(static_cast<char>(value));
-            put_padding(used_by_right_padding, m_fill);
-            return;
-        }
-        if (m_align == Align::Right) {
-            const auto used_by_left_padding = used_by_padding;
-
-            put_padding(used_by_left_padding, m_fill);
-            builder.append(static_cast<char>(value));
-            return;
-        }
-
-        ASSERT_NOT_REACHED();
-    }
-
-    PrintfImplementation::Align align;
-    if (m_align == Align::Left)
-        align = PrintfImplementation::Align::Left;
-    else if (m_align == Align::Right)
-        align = PrintfImplementation::Align::Right;
-    else if (m_align == Align::Center)
-        align = PrintfImplementation::Align::Center;
-    else if (m_align == Align::Default)
-        align = PrintfImplementation::Align::Right;
-    else
-        ASSERT_NOT_REACHED();
-
-    PrintfImplementation::SignMode sign_mode;
-    if (m_sign == Sign::Default)
-        sign_mode = PrintfImplementation::SignMode::OnlyIfNeeded;
-    else if (m_sign == Sign::NegativeOnly)
-        sign_mode = PrintfImplementation::SignMode::OnlyIfNeeded;
-    else if (m_sign == Sign::PositiveAndNegative)
-        sign_mode = PrintfImplementation::SignMode::Always;
-    else if (m_sign == Sign::ReserveSpace)
-        sign_mode = PrintfImplementation::SignMode::Reserved;
-    else
-        ASSERT_NOT_REACHED();
+    const auto width = params.decode(m_width);
 
     if (IsSame<typename MakeUnsigned<T>::Type, T>::value)
-        PrintfImplementation::convert_unsigned_to_string(value, builder, base, m_alternative_form, upper_case, m_zero_pad, align, width, m_fill, sign_mode);
+        builder.put_u64(value, base, m_alternative_form, upper_case, m_zero_pad, m_align, width, m_fill, m_sign_mode);
     else
-        PrintfImplementation::convert_signed_to_string(value, builder, base, m_alternative_form, upper_case, m_zero_pad, align, width, m_fill, sign_mode);
+        builder.put_i64(value, base, m_alternative_form, upper_case, m_zero_pad, m_align, width, m_fill, m_sign_mode);
 }
 
-void Formatter<bool>::format(StringBuilder& builder, bool value, FormatterContext& context)
+void Formatter<bool>::format(TypeErasedFormatParams& params, FormatBuilder& builder, bool value)
 {
     if (m_mode == Mode::Binary || m_mode == Mode::BinaryUppercase || m_mode == Mode::Decimal || m_mode == Mode::Octal || m_mode == Mode::Hexadecimal || m_mode == Mode::HexadecimalUppercase) {
         Formatter<u8> formatter { *this };
-        return formatter.format(builder, static_cast<u8>(value), context);
+        return formatter.format(params, builder, static_cast<u8>(value));
     } else {
         Formatter<StringView> formatter { *this };
-        formatter.format(builder, value ? "true" : "false", context);
+        return formatter.format(params, builder, value ? "true" : "false");
     }
 }
 
diff --git a/AK/Format.h b/AK/Format.h
index cf20ae942c..a8b479d6f9 100644
--- a/AK/Format.h
+++ b/AK/Format.h
@@ -27,6 +27,7 @@
 #pragma once
 
 #include <AK/Array.h>
+#include <AK/GenericLexer.h>
 #include <AK/StringView.h>
 
 // FIXME: I would really love to merge the format_value and make_type_erased_parameters functions,
@@ -35,9 +36,15 @@
 
 namespace AK {
 
+class TypeErasedFormatParams;
+class FormatParser;
+class FormatBuilder;
+
 template<typename T, typename = void>
 struct Formatter;
 
+constexpr size_t max_format_arguments = 256;
+
 struct TypeErasedParameter {
     enum class Type {
         UInt8,
@@ -76,65 +83,131 @@ struct TypeErasedParameter {
 
     const void* value;
     Type type;
-    void (*formatter)(StringBuilder& builder, const void* value, class FormatterContext&);
+    void (*formatter)(TypeErasedFormatParams&, FormatBuilder&, FormatParser&, const void* value);
 };
 
-class FormatterContext {
+class FormatParser : public GenericLexer {
 public:
-    FormatterContext(Span<const TypeErasedParameter> parameters)
-        : m_parameters(parameters)
+    struct FormatSpecifier {
+        StringView flags;
+        size_t index;
+    };
+
+    explicit FormatParser(StringView input);
+
+    StringView consume_literal();
+    bool consume_number(size_t& value);
+    bool consume_specifier(FormatSpecifier& specifier);
+    bool consume_replacement_field(size_t& index);
+};
+
+class FormatBuilder {
+public:
+    enum class Align {
+        Default,
+        Left,
+        Center,
+        Right,
+    };
+    enum class SignMode {
+        OnlyIfNeeded,
+        Always,
+        Reserved,
+        Default = OnlyIfNeeded,
+    };
+
+    explicit FormatBuilder(StringBuilder& builder)
+        : m_builder(builder)
     {
     }
 
-    const TypeErasedParameter& parameter_at(size_t index) const { return m_parameters.at(index); }
-    size_t parameter_count() const { return m_parameters.size(); }
+    void put_padding(char fill, size_t amount);
+
+    void put_literal(StringView value);
+
+    void put_string(
+        StringView value,
+        Align align = Align::Left,
+        size_t min_width = 0,
+        size_t max_width = NumericLimits<size_t>::max(),
+        char fill = ' ');
+
+    void put_u64(
+        u64 value,
+        u8 base = 10,
+        bool prefix = false,
+        bool upper_case = false,
+        bool zero_pad = false,
+        Align align = Align::Right,
+        size_t min_width = 0,
+        char fill = ' ',
+        SignMode sign_mode = SignMode::OnlyIfNeeded,
+        bool is_negative = false);
+
+    void put_i64(
+        i64 value,
+        u8 base = 10,
+        bool prefix = false,
+        bool upper_case = false,
+        bool zero_pad = false,
+        Align align = Align::Right,
+        size_t min_width = 0,
+        char fill = ' ',
+        SignMode sign_mode = SignMode::OnlyIfNeeded);
+
+    const StringBuilder& builder() const { return m_builder; }
+    StringBuilder& builder() { return m_builder; }
+
+private:
+    StringBuilder& m_builder;
+};
+
+class TypeErasedFormatParams {
+public:
+    explicit TypeErasedFormatParams(Span<const TypeErasedParameter> parameters)
+        : m_parameters(parameters)
+    {
+    }
 
-    StringView flags() const { return m_flags; }
-    void set_flags(StringView value) { m_flags = value; }
+    Span<const TypeErasedParameter> parameters() const { return m_parameters; }
 
     size_t take_next_index() { return m_next_index++; }
 
+    size_t decode(size_t value, size_t default_value = 0);
+
 private:
     Span<const TypeErasedParameter> m_parameters;
-    StringView m_flags;
     size_t m_next_index { 0 };
 };
 
-} // namespace AK
-
-namespace AK::Detail::Format {
-
 template<typename T>
-void format_value(StringBuilder& builder, const void* value, FormatterContext& context)
+void __format_value(TypeErasedFormatParams& params, FormatBuilder& builder, FormatParser& parser, const void* value)
 {
     Formatter<T> formatter;
 
-    formatter.parse(context);
-    formatter.format(builder, *static_cast<const T*>(value), context);
+    formatter.parse(params, parser);
+    formatter.format(params, builder, *static_cast<const T*>(value));
 }
 
-} // namespace AK::Detail::Format
+template<typename... Parameters>
+class VariadicFormatParams : public TypeErasedFormatParams {
+public:
+    static_assert(sizeof...(Parameters) <= max_format_arguments);
 
-namespace AK {
+    explicit VariadicFormatParams(const Parameters&... parameters)
+        : TypeErasedFormatParams(m_data)
+        , m_data({ TypeErasedParameter { &parameters, TypeErasedParameter::get_type<Parameters>(), __format_value<Parameters> }... })
+    {
+    }
 
-constexpr size_t max_format_arguments = 256;
+private:
+    Array<TypeErasedParameter, sizeof...(Parameters)> m_data;
+};
 
 // We use the same format for most types for consistency. This is taken directly from std::format.
 // Not all valid options do anything yet.
 // https://en.cppreference.com/w/cpp/utility/format/formatter#Standard_format_specification
 struct StandardFormatter {
-    enum class Align {
-        Default,
-        Left,
-        Right,
-        Center,
-    };
-    enum class Sign {
-        NegativeOnly,
-        PositiveAndNegative,
-        ReserveSpace,
-        Default = NegativeOnly
-    };
     enum class Mode {
         Default,
         Binary,
@@ -148,12 +221,12 @@ struct StandardFormatter {
         Pointer,
     };
 
-    static constexpr size_t value_not_set = 0;
-    static constexpr size_t value_from_next_arg = NumericLimits<size_t>::max();
-    static constexpr size_t value_from_arg = NumericLimits<size_t>::max() - max_format_arguments - 1;
+    static constexpr size_t value_not_set = NumericLimits<size_t>::max();
+    static constexpr size_t value_from_next_arg = NumericLimits<size_t>::max() - 1;
+    static constexpr size_t value_from_arg = NumericLimits<size_t>::max() - max_format_arguments - 2;
 
-    Align m_align = Align::Default;
-    Sign m_sign = Sign::NegativeOnly;
+    FormatBuilder::Align m_align = FormatBuilder::Align::Default;
+    FormatBuilder::SignMode m_sign_mode = FormatBuilder::SignMode::OnlyIfNeeded;
     Mode m_mode = Mode::Default;
     bool m_alternative_form = false;
     char m_fill = ' ';
@@ -161,7 +234,7 @@ struct StandardFormatter {
     size_t m_width = value_not_set;
     size_t m_precision = value_not_set;
 
-    void parse(FormatterContext&);
+    void parse(TypeErasedFormatParams&, FormatParser&);
 };
 
 template<>
@@ -172,7 +245,7 @@ struct Formatter<StringView> : StandardFormatter {
     {
     }
 
-    void format(StringBuilder& builder, StringView value, FormatterContext&);
+    void format(TypeErasedFormatParams&, FormatBuilder&, StringView value);
 };
 template<>
 struct Formatter<const char*> : Formatter<StringView> {
@@ -195,32 +268,24 @@ struct Formatter<T, typename EnableIf<IsIntegral<T>::value>::Type> : StandardFor
     {
     }
 
-    void format(StringBuilder&, T value, FormatterContext&);
+    void format(TypeErasedFormatParams&, FormatBuilder&, T value);
 };
 
 template<typename T>
 struct Formatter<T*> : StandardFormatter {
-    void format(StringBuilder& builder, T* value, FormatterContext& context)
+    void format(TypeErasedFormatParams& params, FormatBuilder& builder, T* value)
     {
         Formatter<FlatPtr> formatter { *this };
-        formatter.format(builder, reinterpret_cast<FlatPtr>(value), context);
+        formatter.format(params, builder, reinterpret_cast<FlatPtr>(value));
     }
 };
 
 template<>
 struct Formatter<bool> : StandardFormatter {
-    void format(StringBuilder&, bool value, FormatterContext&);
+    void format(TypeErasedFormatParams&, FormatBuilder&, bool value);
 };
 
-template<typename... Parameters>
-Array<TypeErasedParameter, sizeof...(Parameters)> make_type_erased_parameters(const Parameters&... parameters)
-{
-    static_assert(sizeof...(Parameters) <= max_format_arguments);
-
-    return { TypeErasedParameter { &parameters, TypeErasedParameter::get_type<Parameters>(), Detail::Format::format_value<Parameters> }... };
-}
-
-void vformat(StringBuilder& builder, StringView fmtstr, Span<const TypeErasedParameter>);
-void vformat(const LogStream& stream, StringView fmtstr, Span<const TypeErasedParameter>);
+void vformat(StringBuilder& builder, StringView fmtstr, TypeErasedFormatParams);
+void vformat(const LogStream& stream, StringView fmtstr, TypeErasedFormatParams);
 
 } // namespace AK
diff --git a/AK/GenericLexer.cpp b/AK/GenericLexer.cpp
index ff78aa9f9e..582ccf9a45 100644
--- a/AK/GenericLexer.cpp
+++ b/AK/GenericLexer.cpp
@@ -26,6 +26,7 @@
 
 #include <AK/Assertions.h>
 #include <AK/GenericLexer.h>
+#include <AK/String.h>
 #include <AK/StringBuilder.h>
 
 namespace AK {
diff --git a/AK/GenericLexer.h b/AK/GenericLexer.h
index bac642b828..0e0ffa9bc4 100644
--- a/AK/GenericLexer.h
+++ b/AK/GenericLexer.h
@@ -26,7 +26,6 @@
 
 #pragma once
 
-#include <AK/String.h>
 #include <AK/StringView.h>
 
 namespace AK {
diff --git a/AK/LogStream.h b/AK/LogStream.h
index 5cbafccadf..b68925465e 100644
--- a/AK/LogStream.h
+++ b/AK/LogStream.h
@@ -211,22 +211,19 @@ void dump_bytes(ReadonlyBytes);
 template<typename... Parameters>
 void outf(StringView fmtstr, const Parameters&... parameters)
 {
-    const auto type_erased_parameters = make_type_erased_parameters(parameters...);
-    vformat(out(), fmtstr, type_erased_parameters);
+    vformat(out(), fmtstr, VariadicFormatParams { parameters... });
 }
 template<typename... Parameters>
 void warnf(StringView fmtstr, const Parameters&... parameters)
 {
-    const auto type_erased_parameters = make_type_erased_parameters(parameters...);
-    vformat(warn(), fmtstr, type_erased_parameters);
+    vformat(warn(), fmtstr, VariadicFormatParams { parameters... });
 }
 #endif
 
 template<typename... Parameters>
 void dbgf(StringView fmtstr, const Parameters&... parameters)
 {
-    const auto type_erased_parameters = make_type_erased_parameters(parameters...);
-    vformat(dbg(), fmtstr, type_erased_parameters);
+    vformat(dbg(), fmtstr, VariadicFormatParams { parameters... });
 }
 
 }
diff --git a/AK/PrintfImplementation.h b/AK/PrintfImplementation.h
index f7926968c2..fc4179feef 100644
--- a/AK/PrintfImplementation.h
+++ b/AK/PrintfImplementation.h
@@ -38,172 +38,6 @@ namespace PrintfImplementation {
 static constexpr const char* printf_hex_digits_lower = "0123456789abcdef";
 static constexpr const char* printf_hex_digits_upper = "0123456789ABCDEF";
 
-enum class Align {
-    Left,
-    Center,
-    Right,
-};
-
-enum class SignMode {
-    OnlyIfNeeded,
-    Always,
-    Reserved
-};
-
-// The worst case is that we have the largest 64-bit value formatted as binary number, this would take
-// 65 bytes. Choosing a larger power of two won't hurt and is a bit of mitigation against out-of-bounds accesses.
-inline size_t convert_unsigned_to_string(u64 value, Array<u8, 128>& buffer, u8 base, bool upper_case)
-{
-    ASSERT(base >= 2 && base <= 16);
-
-    static constexpr const char* lowercase_lookup = "0123456789abcdef";
-    static constexpr const char* uppercase_lookup = "0123456789ABCDEF";
-
-    if (value == 0) {
-        buffer[0] = '0';
-        return 1;
-    }
-
-    size_t used = 0;
-    while (value > 0) {
-        if (upper_case)
-            buffer[used++] = uppercase_lookup[value % base];
-        else
-            buffer[used++] = lowercase_lookup[value % base];
-
-        value /= base;
-    }
-
-    // Reverse the list; I came up with this logic in like three seconds so it's probably wrong in some edge case.
-    for (size_t i = 0; i < used / 2; ++i)
-        swap(buffer[i], buffer[used - i - 1]);
-
-    return used;
-}
-
-inline size_t convert_unsigned_to_string(
-    u64 value,
-    StringBuilder& builder,
-    u8 base = 10,
-    bool prefix = false,
-    bool upper_case = false,
-    bool zero_pad = false,
-    Align align = Align::Right,
-    size_t width = 0,
-    char fill = ' ',
-    SignMode sign_mode = SignMode::OnlyIfNeeded,
-    bool is_negative = false)
-{
-    Array<u8, 128> buffer;
-
-    const auto used_by_significant_digits = convert_unsigned_to_string(value, buffer, base, upper_case);
-    size_t used_by_prefix = sign_mode == SignMode::OnlyIfNeeded ? static_cast<size_t>(is_negative) : 1;
-
-    if (prefix) {
-        if (base == 8)
-            used_by_prefix += 1;
-        else if (base == 16)
-            used_by_prefix += 2;
-        else if (base == 2)
-            used_by_prefix += 2;
-    }
-
-    const auto put_prefix = [&]() {
-        if (is_negative)
-            builder.append('-');
-        else if (sign_mode == SignMode::Always)
-            builder.append('+');
-        else if (sign_mode == SignMode::Reserved)
-            builder.append(' ');
-
-        if (prefix) {
-            if (base == 2) {
-                if (upper_case)
-                    builder.append("0B");
-                else
-                    builder.append("0b");
-            } else if (base == 8) {
-                builder.append("0");
-            } else if (base == 16) {
-                if (upper_case)
-                    builder.append("0X");
-                else
-                    builder.append("0x");
-            }
-        }
-    };
-    const auto put_padding = [&](size_t amount, char fill) {
-        for (size_t i = 0; i < amount; ++i)
-            builder.append(fill);
-    };
-    const auto put_digits = [&]() {
-        builder.append(StringView { buffer.span().trim(used_by_significant_digits) });
-    };
-
-    const auto used_by_field = used_by_significant_digits + used_by_prefix;
-    const auto used_by_padding = width < used_by_field ? 0 : width - used_by_field;
-
-    if (align == Align::Left) {
-        const auto used_by_right_padding = used_by_padding;
-
-        put_prefix();
-        put_digits();
-        put_padding(used_by_right_padding, fill);
-
-        return used_by_field + used_by_right_padding;
-    }
-
-    if (align == Align::Center) {
-        const auto used_by_left_padding = used_by_padding / 2;
-        const auto used_by_right_padding = ceil_div<size_t, size_t>(used_by_padding, 2);
-
-        put_padding(used_by_left_padding, fill);
-        put_prefix();
-        put_digits();
-        put_padding(used_by_right_padding, fill);
-
-        return used_by_left_padding + used_by_field + used_by_right_padding;
-    }
-
-    if (align == Align::Right) {
-        const auto used_by_left_padding = used_by_padding;
-
-        if (zero_pad) {
-            put_prefix();
-            put_padding(used_by_left_padding, '0');
-            put_digits();
-        } else {
-            put_padding(used_by_left_padding, fill);
-            put_prefix();
-            put_digits();
-        }
-
-        return used_by_field + used_by_left_padding;
-    }
-
-    ASSERT_NOT_REACHED();
-}
-
-inline size_t convert_signed_to_string(
-    i64 value,
-    StringBuilder& builder,
-    u8 base = 10,
-    bool common_prefix = false,
-    bool upper_case = false,
-    bool zero_pad = false,
-    Align align = Align::Right,
-    size_t width = 0,
-    char fill = ' ',
-    SignMode sign_mode = SignMode::OnlyIfNeeded)
-{
-    bool is_negative = value < 0;
-
-    if (value < 0)
-        value = -value;
-
-    return convert_unsigned_to_string(static_cast<size_t>(value), builder, base, common_prefix, upper_case, zero_pad, align, width, fill, sign_mode, is_negative);
-}
-
 #ifdef __serenity__
 extern "C" size_t strlen(const char*);
 #else
diff --git a/AK/String.cpp b/AK/String.cpp
index ebb5c70dbc..177844fb61 100644
--- a/AK/String.cpp
+++ b/AK/String.cpp
@@ -441,10 +441,10 @@ InputStream& operator>>(InputStream& stream, String& string)
     }
 }
 
-String String::vformatted(StringView fmtstr, Span<const TypeErasedParameter> parameters)
+String String::vformatted(StringView fmtstr, TypeErasedFormatParams params)
 {
     StringBuilder builder;
-    vformat(builder, fmtstr, parameters);
+    vformat(builder, fmtstr, params);
     return builder.to_string();
 }
 
diff --git a/AK/String.h b/AK/String.h
index e5b0d1ef0d..0d2cb3386a 100644
--- a/AK/String.h
+++ b/AK/String.h
@@ -239,13 +239,12 @@ public:
 
     static String format(const char*, ...);
 
-    static String vformatted(StringView fmtstr, Span<const TypeErasedParameter>);
+    static String vformatted(StringView fmtstr, TypeErasedFormatParams);
 
     template<typename... Parameters>
     static String formatted(StringView fmtstr, const Parameters&... parameters)
     {
-        const auto type_erased_parameters = make_type_erased_parameters(parameters...);
-        return vformatted(fmtstr, type_erased_parameters);
+        return vformatted(fmtstr, VariadicFormatParams { parameters... });
     }
 
     template<typename T>
diff --git a/AK/StringBuilder.h b/AK/StringBuilder.h
index 54515a81bd..2ef784b29a 100644
--- a/AK/StringBuilder.h
+++ b/AK/StringBuilder.h
@@ -52,8 +52,7 @@ public:
     template<typename... Parameters>
     void appendff(StringView fmtstr, const Parameters&... parameters)
     {
-        const auto type_erased_parameters = make_type_erased_parameters(parameters...);
-        vformat(*this, fmtstr, type_erased_parameters);
+        vformat(*this, fmtstr, VariadicFormatParams { parameters... });
     }
 
     String build() const;
diff --git a/AK/Tests/TestFormat.cpp b/AK/Tests/TestFormat.cpp
index 2441303e6d..fca71b7451 100644
--- a/AK/Tests/TestFormat.cpp
+++ b/AK/Tests/TestFormat.cpp
@@ -162,4 +162,22 @@ TEST_CASE(pointers)
     }
 }
 
+// If the format implementation did absolutely nothing, all tests would pass. This
+// is because when a test fails we only write "FAIL" to stdout using format.
+//
+// This is a bit scary, thus this test. At least this test should fail in this case.
+TEST_CASE(ensure_that_format_works)
+{
+
+    if (String::formatted("FAIL") != "FAIL") {
+        fprintf(stderr, "FAIL\n");
+        exit(1);
+    }
+
+    if (String::formatted("{} FAIL {}", 1, 2) != "1 FAIL 2") {
+        fprintf(stderr, "FAIL\n");
+        exit(1);
+    }
+}
+
 TEST_MAIN(Format)
diff --git a/AK/Tests/TestPrintf.cpp b/AK/Tests/TestPrintf.cpp
deleted file mode 100644
index 84c455d744..0000000000
--- a/AK/Tests/TestPrintf.cpp
+++ /dev/null
@@ -1,124 +0,0 @@
-/*
- * 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 <AK/TestSuite.h>
-
-#include <AK/PrintfImplementation.h>
-#include <AK/StringBuilder.h>
-
-TEST_CASE(format_unsigned_with_internal_implementation)
-{
-    Array<u8, 128> buffer;
-    size_t used = 0;
-
-    used = PrintfImplementation::convert_unsigned_to_string(12341234, buffer, 10, false);
-    EXPECT_EQ(StringView { buffer.span().trim(used) }, "12341234");
-
-    used = PrintfImplementation::convert_unsigned_to_string(12341234, buffer, 16, false);
-    EXPECT_EQ(StringView { buffer.span().trim(used) }, "bc4ff2");
-
-    used = PrintfImplementation::convert_unsigned_to_string(12341234, buffer, 16, true);
-    EXPECT_EQ(StringView { buffer.span().trim(used) }, "BC4FF2");
-
-    used = PrintfImplementation::convert_unsigned_to_string(0, buffer, 10, true);
-    EXPECT_EQ(StringView { buffer.span().trim(used) }, "0");
-
-    used = PrintfImplementation::convert_unsigned_to_string(NumericLimits<u64>::max(), buffer, 10, true);
-    EXPECT_EQ(StringView { buffer.span().trim(used) }, "18446744073709551615");
-}
-
-TEST_CASE(format_unsigned_just_pass_through)
-{
-    StringBuilder builder;
-    size_t used = 0;
-
-    builder.clear();
-    used = PrintfImplementation::convert_unsigned_to_string(12341234, builder);
-    EXPECT_EQ(used, 8u);
-    EXPECT_EQ(builder.to_string(), "12341234");
-
-    builder.clear();
-    used = PrintfImplementation::convert_unsigned_to_string(12341234, builder, 16);
-    EXPECT_EQ(used, 6u);
-    EXPECT_EQ(builder.to_string(), "bc4ff2");
-
-    builder.clear();
-    used = PrintfImplementation::convert_unsigned_to_string(12341234, builder, 16, false, true);
-    EXPECT_EQ(used, 6u);
-    EXPECT_EQ(builder.to_string(), "BC4FF2");
-}
-
-TEST_CASE(format_unsigned)
-{
-    StringBuilder builder;
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Right, 4, '*', PrintfImplementation::SignMode::OnlyIfNeeded);
-    EXPECT_EQ(builder.to_string(), "0042");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Left, 4, '*', PrintfImplementation::SignMode::OnlyIfNeeded);
-    EXPECT_EQ(builder.to_string(), "42**");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Center, 4, '*', PrintfImplementation::SignMode::OnlyIfNeeded);
-    EXPECT_EQ(builder.to_string(), "*42*");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Center, 9, '*', PrintfImplementation::SignMode::OnlyIfNeeded);
-    EXPECT_EQ(builder.to_string(), "***42****");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Center, 9, '*', PrintfImplementation::SignMode::Reserved);
-    EXPECT_EQ(builder.to_string(), "*** 42***");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Left, 4, '*', PrintfImplementation::SignMode::Always, true);
-    EXPECT_EQ(builder.to_string(), "-42*");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Center, 4, '*', PrintfImplementation::SignMode::Reserved, true);
-    EXPECT_EQ(builder.to_string(), "-42*");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(42, builder, 10, false, false, true, PrintfImplementation::Align::Right, 4, '*', PrintfImplementation::SignMode::OnlyIfNeeded, true);
-    EXPECT_EQ(builder.to_string(), "-042");
-
-    builder.clear();
-    PrintfImplementation::convert_unsigned_to_string(32, builder, 16, true, false, true, PrintfImplementation::Align::Right, 8, '*', PrintfImplementation::SignMode::OnlyIfNeeded, true);
-    EXPECT_EQ(builder.to_string(), "-0x00020");
-}
-
-TEST_CASE(format_signed)
-{
-    StringBuilder builder;
-
-    builder.clear();
-    PrintfImplementation::convert_signed_to_string(42, builder, 10, false, false, false, PrintfImplementation::Align::Right, 8, '/', PrintfImplementation::SignMode::OnlyIfNeeded);
-    EXPECT_EQ(builder.to_string(), "//////42");
-}
-
-TEST_MAIN(Printf)