Hi, I’m using the new functionality of outgoing HTTP requests with Motoko and parsing the json response is not an easy task. Basically, I receive a decimal number that I need to perform mathematical operations with. This number is received in Text format and I can’t figure out how to convert it to Float type…

After spending a while on it, I wrote a piece of code that seems to do the trick :

public func textToFloat(t : Text) : async Float {
var i : Float = 1;
var f : Float = 0;
var isDecimal : Bool = false;
for (c in t.chars()) {
if (Char.isDigit(c)) {
let charToNat : Nat64 = Nat64.fromNat(Nat32.toNat(Char.toNat32(c) -48));
let natToFloat : Float = Float.fromInt64(Int64.fromNat64(charToNat));
if (isDecimal) {
let n : Float = natToFloat / Float.pow(10, i);
f := f + n;
} else {
f := f * 10 + natToFloat;
};
i := i + 1;
} else {
if (Char.equal(c, '.') or Char.equal(c, ',')) {
f := f / Float.pow(10, i); // Force decimal
f := f * Float.pow(10, i); // Correction
isDecimal := true;
i := 1;
} else {
throw Error.reject("NaN");
};
};
};
return f;
};