From 9a711c28b977d01b1b1b79ab1f16f3c1dbe9e343 Mon Sep 17 00:00:00 2001
From: Per Lundberg <perlun@gmail.com>
Date: Fri, 13 Oct 2023 21:59:12 +0300
Subject: [PATCH] WIP: Let's try to extract this to a separate PR another day.

---
 src/Perlang.Parser/NumberParser.cs                  | 13 +++++++++++--
 .../Operator/Binary/BinaryOperatorData.cs           |  2 +-
 src/stdlib/test/print.cc                            | 10 +++++++---
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/Perlang.Parser/NumberParser.cs b/src/Perlang.Parser/NumberParser.cs
index 9caa8bc1..395fe725 100644
--- a/src/Perlang.Parser/NumberParser.cs
+++ b/src/Perlang.Parser/NumberParser.cs
@@ -22,8 +22,17 @@ public static INumericLiteral Parse(NumericToken numericToken)
                     {
                         // The explicit IFormatProvider is required to ensure we use 123.45 format, regardless of host OS
                         // language/region settings. See #263 for more details.
-                        float value = Single.Parse(numberCharacters, CultureInfo.InvariantCulture);
-                        return new FloatingPointLiteral<float>(value);
+                        //
+                        // An interesting detail: despite this being a `float` value, we parse it as a double since we
+                        // might otherwise loose valuable precision. This is critical for working with numbers like
+                        // 340282349999999991754788743781432688640.0f; parsing it as a Single at this point will round
+                        // it to 3.4028235E+38 which looses a significant amount of precision. This is particularly
+                        // important to get proper semantics for `double + float` operations.
+
+                        // TODO: Try to extract this change + changes to BinaryOperatorData to a PR of its own. Should
+                        // work, and help provide smaller, more maintainable PRs.
+                        double value = Double.Parse(numberCharacters, CultureInfo.InvariantCulture);
+                        return new FloatingPointLiteral<double>(value);
                     }
 
                     case 'd':
diff --git a/src/Perlang.Tests.Integration/Operator/Binary/BinaryOperatorData.cs b/src/Perlang.Tests.Integration/Operator/Binary/BinaryOperatorData.cs
index ec79de7c..f855ed24 100644
--- a/src/Perlang.Tests.Integration/Operator/Binary/BinaryOperatorData.cs
+++ b/src/Perlang.Tests.Integration/Operator/Binary/BinaryOperatorData.cs
@@ -341,7 +341,7 @@ public static class BinaryOperatorData
         {
             new object[] { "12", "34", "false" },
             new object[] { "12", "12", "true" },
-            new object[] { "12", "12.0", "false" }, // Same value but different types. Note: this is truthy in C# AND Java.
+            new object[] { "12", "12.0", "false" }, // Same value but different types. Note: this is truthy in C# AND Java. AND C++! We want to
             new object[] { "12.0", "12", "false" }, // Same value but different types. Note: this is truthy in C# AND Java.
             new object[] { "12.345", "12.345", "true" },
             new object[] { "12.345", "67.890", "false" },
diff --git a/src/stdlib/test/print.cc b/src/stdlib/test/print.cc
index ba2658af..a043eef5 100644
--- a/src/stdlib/test/print.cc
+++ b/src/stdlib/test/print.cc
@@ -86,7 +86,11 @@ TEST(PrintDouble_4294967283)
 
 TEST(PrintDouble_9223372036854775807)
 {
-    fwrite_mocked = true;
-    perlang::print(9223372036854775807.0);
-    fwrite_mocked = false;
+    float f = 12.0;
+    int i = 12;
+    perlang::print(f == i);
+
+//    fwrite_mocked = true;
+//    perlang::print(9223372036854775807.0);
+//    fwrite_mocked = false;
 }
\ No newline at end of file