improve fromString

Author: munrocket

dist/double.esm.js

@@ -55,11 +55,14 @@ class Double {
     return new Double(oneSqr(a));
   }
   static fromString(s) {
-    let isPositive = /^\s*-/.exec(s) === null;
-    s = s.replace(/^\s*[+-]?/, "");
-    if (/Infinity.*/.exec(s) !== null)
+    s = s.trim();
+    let first = s[0];
+    let isPositive = first != "-";
+    if (first == "+" || first == "-")
+      s = s.slice(1);
+    if (s.includes("Infinity"))
       return isPositive ? Double.Infinity : Double.neg2(Double.Infinity);
-    let rex = /^([0-9]*\.?[0-9]+)(?:[eE]([-+]?[0-9]+))?/.exec(s);
+    let rex = /^(\d*\.?\d+)(?:[eE]([-+]?\d+))?/.exec(s);
     if (!rex)
       return Double.NaN;
     let digits = rex[1].replace(".", "");

dist/double.js

@@ -57,11 +57,14 @@
       return new Double(oneSqr(a));
     }
     static fromString(s) {
-      let isPositive = /^\s*-/.exec(s) === null;
-      s = s.replace(/^\s*[+-]?/, "");
-      if (/Infinity.*/.exec(s) !== null)
+      s = s.trim();
+      let first = s[0];
+      let isPositive = first != "-";
+      if (first == "+" || first == "-")
+        s = s.slice(1);
+      if (s.includes("Infinity"))
         return isPositive ? Double.Infinity : Double.neg2(Double.Infinity);
-      let rex = /^([0-9]*\.?[0-9]+)(?:[eE]([-+]?[0-9]+))?/.exec(s);
+      let rex = /^(\d*\.?\d+)(?:[eE]([-+]?\d+))?/.exec(s);
       if (!rex)
         return Double.NaN;
       let digits = rex[1].replace(".", "");

package.json

@@ -1,6 +1,6 @@
 {
   "name": "double.js",
-  "version": "1.1.2",
+  "version": "1.1.3",
   "description": "Emulated float128 or double-double arithmetic. A floating point expansion with 31 accurate decimal digits.",
   "main": "dist/double.js",
   "module": "dist/double.esm.js",

src/double.ts

@@ -62,10 +62,12 @@ class Double {
   static fromMul11(a: float, b: float): Double { return new Double(twoProd(a, b)); }
   static fromSqr1(a: float): Double { return new Double(oneSqr(a)); }
   static fromString(s: string): Double {
-    let isPositive = (/^\s*-/.exec(s) === null);
-    s = s.replace(/^\s*[+-]?/, '');
-    if (/Infinity.*/.exec(s) !== null) return (isPositive) ? Double.Infinity : Double.neg2(Double.Infinity);
-    let rex = /^([0-9]*\.?[0-9]+)(?:[eE]([-+]?[0-9]+))?/.exec(s);
+    s = s.trim();
+    let first = s[0]
+    let isPositive = first != '-';
+    if (first == '+' || first == '-') s = s.slice(1);
+    if (s.includes('Infinity')) return (isPositive) ? Double.Infinity : Double.neg2(Double.Infinity);
+    let rex = /^(\d*\.?\d+)(?:[eE]([-+]?\d+))?/.exec(s);
     if (!rex) return Double.NaN;
 
     let digits = rex[1].replace('.', '');