Clarify that Float does not include NaN or infinity

glasser · leebyron · commit 00dcf974a116 · 2021-04-05T23:30:54.000-07:00
Fixes #778. This matches the fact that you cannot represent these values in text as FloatValue, as well as the graphql-js implementation (https://github.com/graphql/graphql-js/blob/16009cbcb0109da03f2157a868817b886801095a/src/type/scalars.js#L108-L112). This was perhaps already implied by the word "fractional", but "finite" seems to be a more standard term for "IEEE 754 floats that are not infinity or NaN".
diff --git a/spec/Section 3 -- Type System.md b/spec/Section 3 -- Type System.md
@@ -450,10 +450,11 @@ encoding integer numbers larger than 32-bit.
 
 ### Float
 
-The Float scalar type represents signed double-precision fractional values
-as specified by [IEEE 754](https://en.wikipedia.org/wiki/IEEE_floating_point).
-Response formats that support an appropriate double-precision number type
-should use that type to represent this scalar.
+The Float scalar type represents signed double-precision finite (i.e., not {NaN}
+or infinity) fractional values as specified by
+[IEEE 754](https://en.wikipedia.org/wiki/IEEE_floating_point).  Response formats
+that support an appropriate double-precision number type should use that type to
+represent this scalar.
 
 **Result Coercion**
 
