Stricter number parsing #8129
Stricter number parsing #8129
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…String for stricter parsing
for stricter number parsing
rescript
@rescript/darwin-arm64
@rescript/darwin-x64
@rescript/linux-arm64
@rescript/linux-x64
@rescript/runtime
@rescript/win32-x64
commit: |
| let fromString: string => option<float> = %raw(`str => { | ||
| if (!str || !str.trim()) return; | ||
| let num = +str; | ||
| return isNaN(num) ? undefined : num; | ||
| }`) |
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I wrote some fast-check tests and couldn't find a difference between +str and Number(str), but the latter is easier to understand and could be written in pure ReScript.
How about converting this function to ReScript?
%%private(
@val external makeNumber: 'a => float = "Number"
@send external trim: string => string = "trim"
)
let fromString: string => option<float> = str =>
if Js.typeof(str) === "string" && trim(str) !== "" {
let num = makeNumber(str)
isNaN(num) ? None : Some
} else {
None
}BTW just saw this, but I don't think the performance difference between +x and Number(x) should be a factor in this decision. However, my tests show the difference is nearly non-existent:
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Yes, it's solely for performance, otherwise it should be equivalent. There might not be a noticeable difference when optimized anymore, but there are still situations where the might not be optimized and `Number would be significantly slower. If this is relevant here I'm not sure of though.
Another option is to just add a comment.
2 participants
Fixes rescript-core/#257
Besides stricter number parsing, this also removes the radix argument in favor of supporting hexadecimal, binary and exponential notation directly.