2 files changed, 83 insertions, 4 deletions
diff --git a/source/fud_format.cpp b/source/fud_format.cpp
index f3e6894..960a146 100644
--- a/source/fud_format.cpp
+++ b/source/fud_format.cpp
@@ -390,9 +390,6 @@ FudStatus getPrecision(StringView& formatView, FormatSpec& spec)
         return precisionResult.takeError();
     }
     auto precisionValue{precisionResult.takeOkay()};
-    if (precisionValue.value < 1) {
-        return FudStatus::FormatInvalid;
-    }
     spec.precision = precisionValue.value;
     if (formatView.length() < precisionValue.nextIndex) {
         return FudStatus::Failure;
@@ -571,6 +568,87 @@ FudStatus fillUnsignedBuffer(
     return FudStatus::Success;
 }
 
+[[nodiscard]] Result<bool, FudStatus> validateFloatFormatType(FormatType formatType)
+{
+    auto uppercase = false;
+
+    switch (formatType) {
+    case FormatType::Unspecified:
+        break;
+    case FormatType::FloatHexLower:
+        break;
+    case FormatType::FloatHexUpper:
+        uppercase = true;
+        break;
+    case FormatType::ScientificLower:
+        break;
+    case FormatType::ScientificUpper:
+        uppercase = true;
+        break;
+    case FormatType::FixedLower:
+        break;
+    case FormatType::FixedUpper:
+        uppercase = true;
+        break;
+    case FormatType::GeneralLower:
+        break;
+    case FormatType::GeneralUpper:
+        uppercase = true;
+        break;
+    case FormatType::Octal:
+    case FormatType::HexLower:
+    case FormatType::HexUpper:
+    case FormatType::Decimal:
+    case FormatType::Character:
+    case FormatType::BinaryLower:
+    case FormatType::BinaryUpper:
+    case FormatType::String:
+    case FormatType::Escaped:
+        return FudStatus::FormatInvalid;
+        break;
+    default:
+        return FudStatus::Failure;
+    }
+
+    return uppercase;
+}
+
+ExponentBuffer getScientificExponent(int exponent, uint8_t& exponentLength, bool uppercase)
+{
+    IntCharArray buffer{};
+    uint8_t bufferLength = 0;
+    auto exponentStatus = fillSignedBuffer(buffer, exponent, bufferLength, Radix::Decimal, true);
+    fudAssert(exponentStatus == FudStatus::Success);
+    fudAssert(bufferLength <= maxDecimalExpLength);
+    ExponentBuffer exponentBuffer{};
+    exponentBuffer[0] = uppercase ? 'E' : 'e';
+    exponentBuffer[1] = exponent < 0 ? '-' : '+';
+
+    switch (bufferLength) {
+    case 0:
+        fudAssert(bufferLength > 0);
+        break;
+    case 1:
+        exponentBuffer[2] = '0';
+        exponentBuffer[3] = buffer[0];
+        break;
+    case 2:
+        exponentBuffer[2] = buffer[0];
+        exponentBuffer[3] = buffer[1];
+        break;
+    case 3:
+        exponentBuffer[2] = buffer[0];
+        exponentBuffer[3] = buffer[1];
+        exponentBuffer[4] = buffer[2];
+        break;
+    default:
+        fudAssert(bufferLength <= maxDecimalExpLength);
+    }
+
+    exponentLength = bufferLength < 3 ? 4 : 5;
+    return exponentBuffer;
+}
+
 } // namespace impl
 
 } // namespace fud
diff --git a/source/fud_string.cpp b/source/fud_string.cpp
index c444a74..3ba6603 100644
--- a/source/fud_string.cpp
+++ b/source/fud_string.cpp
@@ -500,8 +500,9 @@ DrainResult String::drain(StringView source)
     auto* destPtr = data() + length();
     auto status = copyMem(destPtr, remainingLength(), source.data(), source.length());
     fudAssert(status == FudStatus::Success);
+    result.bytesWritten += source.length();
 
-    m_length += source.length();
+    m_length = newLength;
     status = nullTerminate();
 
     return result;