adding f32, f64 formats

format.md

@@ -30,17 +30,10 @@ base         ::= "b" | "o" | "d" | "h"
 
 ```
 b   base 2
-B   base 2, leading zeros
-
 o   base 8
-O   base 8, leading zeros
-
 d   base 10
-
 h   base 16, lower-case letters a-f
-H   base 16, lower-case letters A-F
-
-c   ASCII char string
+A   ASCII char string
 ```
 
 ### zero / sign extension

lib/format.js

@@ -1,30 +1,56 @@
 'use strict';
 
-const format = (fmt, val, len) => {
-  const m1 = fmt.match(/^%(?<sign>[s])?(?<radix>[bodhH])$/);
-  len = BigInt(len);
-  if (m1) {
-    const p = m1.groups;
-    const radix = ({b: 2, o: 8, d: 10, h: 16, H: 16})[p.radix];
-    if (p.sign === 's') {
-      const sign = (val >> (len - 1n)) & 1n;
-      if (sign) {
-        val = val - (2n ** len);
-      }
+const format = (fmt, len) => {
+  {
+    const m1 = fmt.match(/^%(?<sign>[s])?(?<radix>[bodh])$/);
+    len = BigInt(len);
+    if (m1) {
+      const p = m1.groups;
+      const radix = ({b: 2, o: 8, d: 10, h: 16, H: 16})[p.radix];
+      return (val) => {
+        if (p.sign === 's') {
+          const sign = (val >> (len - 1n)) & 1n;
+          if (sign) {
+            val = val - (2n ** len);
+          }
+        }
+        let res = val.toString(radix);
+        return res;
+      };
     }
-    let res = val.toString(radix);
-    if (p.radix === 'H') {
-      return res.toUpperCase();
+  } {
+    const m2 = fmt.match(/^%A$/);
+    if (m2) {
+      return (val) => {
+        let txtRes = '';
+        for (let i = 0n; i < len; i += 8n) {
+          txtRes = String.fromCharCode(Number((val >> i) & 0xffn)) + txtRes;
+        }
+        return txtRes;
+      };
     }
-    return res;
-  }
-  const m2 = fmt.match(/^%A$/);
-  if (m2) {
-    let txtRes = '';
-    for (let i = 0n; i < len; i += 8n) {
-      txtRes = String.fromCharCode(Number((val >> i) & 0xffn)) + txtRes;
+  } {
+    const m3 = fmt.match(/^%f64$/);
+    if (m3) {
+      return (val) => {
+        const buf = new ArrayBuffer(8);
+        const bufFloat = new Float64Array(buf);
+        const bufBInt = new BigInt64Array(buf);
+        bufBInt[0] = val & 0xffffffffffffffffn;
+        return bufFloat[0].toString();
+      };
+    }
+  } {
+    const m3 = fmt.match(/^%f32$/);
+    if (m3) {
+      return (val) => {
+        const buf = new ArrayBuffer(4);
+        const bufFloat = new Float32Array(buf);
+        const bufUInt = new Uint32Array(buf);
+        bufUInt[0] = Number(val & 0xffffffffn);
+        return bufFloat[0].toString();
+      };
     }
-    return txtRes;
   }
 };
 

test/format.js

@@ -3,12 +3,30 @@
 const {expect} = require('chai');
 const format = require('../lib/format.js');
 
+const fp64_2bigint = (val) => {
+  const buf = new ArrayBuffer(8);
+  const bufFloat = new Float64Array(buf);
+  const bufBInt = new BigInt64Array(buf);
+  bufFloat[0] = val;
+  return bufBInt[0];
+};
+
+const fp32_2bigint = (val) => {
+  const buf = new ArrayBuffer(4);
+  const bufFloat = new Float32Array(buf);
+  const bufUInt = new Uint32Array(buf);
+  bufFloat[0] = val;
+  return bufUInt[0];
+};
+
+console.log(fp64_2bigint(123.456).toString(16));
+console.log(fp32_2bigint(123.456).toString(16));
+
 const tt = [
   {fmt: '%b',    val: 12345678n, len: 24, res: '101111000110000101001110'},
   {fmt: '%o',    val: 12345678n, len: 24, res: '57060516'},
   {fmt: '%d',    val: 12345678n, len: 24, res: '12345678'},
   {fmt: '%h',    val: 12345678n, len: 24, res: 'bc614e'},
-  {fmt: '%H',    val: 12345678n, len: 24, res: 'BC614E'},
 
   {fmt: '%sb',   val: 5n, len: 3, res: '-11'},
   {fmt: '%so',   val: 5n, len: 3, res: '-3'},
@@ -19,20 +37,25 @@ const tt = [
   {fmt: '%so',   val: 12345678n, len: 24, res: '-20717262'},
   {fmt: '%sd',   val: 12345678n, len: 24, res: '-4431538'},
   {fmt: '%sh',   val: 12345678n, len: 24, res: '-439eb2'},
-  {fmt: '%sH',   val: 12345678n, len: 24, res: '-439EB2'},
 
   {fmt: '%sb',   val: 12345678n, len: 42, res: '101111000110000101001110'},
   {fmt: '%so',   val: 12345678n, len: 42, res: '57060516'},
   {fmt: '%sd',   val: 12345678n, len: 42, res: '12345678'},
   {fmt: '%sh',   val: 12345678n, len: 42, res: 'bc614e'},
 
   {fmt: '%A',    val: 0x4142434445n, len: 40, res: 'ABCDE'},
+
+  {fmt: '%sh',   val: 12345678n, len: 42, res: 'bc614e'},
+
+  {fmt: '%f64',   val: 0x405edd2f1a9fbe77n, len: 64, res: '123.456'},
+  {fmt: '%f32',   val: 0x42f6e979n, len: 32, res: '123.45600128173828'},
+
 ];
 
 describe('format', () => {
   for (const te of tt) {
     it('t:' + te.fmt + ':' + te.val + ':' + te.len, async () => {
-      expect(format(te.fmt, te.val, te.len)).to.eq(te.res);
+      expect(format(te.fmt, te.len)(te.val)).to.eq(te.res);
     });
   }
 });