more formats

format.md

@@ -0,0 +1,112 @@
+## Value format string syntax
+
+Multibit values can have formated value labels.
+
+Grammar for
+
+```
+label_format ::= ["%" format_spec]
+format_spec  ::= [sign] base
+sign         ::= "s" | "u"
+base         ::= "b" | "o" | "d" | "h"
+```
+
+### sign
+
+```
+"+" indicates that a sign should be used for both positive as well as negative numbers.
+"-" indicates that a sign should be used only for negative numbers.
+```
+
+### alignment
+
+```
+"<" Forces the field to be left-aligned within the available space.
+">" Forces the field to be right-aligned within the available space.
+"^" Forces the field to be centered within the available space.
+```
+
+### base
+
+```
+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
+```
+
+### zero / sign extension
+
+A = 0x0723; B = 0xFF05
+
+| format | base | signed | A      | A3  | A2  | A1 | B                | B3  | B2  | B1  |
+|-|-|-|-|-|-|-|-|-|-|-|
+| %b  | 2       |  | 11100100011  | …11 | …1  | … | 1111111100000101  | …11 | …1  | … |
+| %o  | 8       |  | 3443         | …43 | …3  | … | 177405            | …05 | …5  | … |
+| %d  | 10      |  | 1827         | …27 | …7  | … | 65285             | …85 | …5  | … |
+| %h  | 16      |  | 723          | 723 | …3  | … | ff05              | …05 | …5  | … |
+| %sb | 2       |v | 11100100011  | …11 | +   | + | -11111011         | -…1 | -   | - |
+| %so | 8       |v | 3443         | …43 | +   | + | -373              | -…2 | -   | - |
+| %sd | 10      |v | 1827         | …27 | +   | + | -251              | -…1 | -   | - |
+| %sh | 16      |v | 723          | 723 | +   | + | -fb               | -fb | -   | - |
+
+### other
+
+* decode floating point numbers
+* decode vectors of numbers
+
+
+### Floating point
+
+* https://en.wikipedia.org/wiki/Floating-point_arithmetic
+* https://en.wikipedia.org/wiki/IEEE_754
+* https://en.wikipedia.org/wiki/Bfloat16_floating-point_format
+* https://en.wikipedia.org/wiki/Minifloat
+* https://github.com/hlslibs/ac_types/blob/master/pdfdocs/ac_datatypes_ref.pdf
+
+Fortran
+
+* https://web.math.utk.edu/~vasili/refs/Fortran/AiS-f77/fortran7.10.html
+
+* print floating point numbers in specific form
+ -
+
+```
+.toPrecision
+.toExponential
+.toFixed
+```
+
+### Fixed point
+* specify fixed point number format
+* specific
+
+
+* https://en.wikipedia.org/wiki/Q_(number_format)
+* https://www.ti.com/lit/ug/spru565b/spru565b.pdf
+
+```
+Qf
+Qm.f
+```
+
+### Complex
+
+### Vectors
+
+### Libs
+
+https://github.com/adamwdraper/Numeral-js
+
+### References
+
+* https://en.wikipedia.org/wiki/Printf
+

lib/format.js

@@ -1,20 +1,31 @@
 'use strict';
 
-const format = (fmt, val /*, len*/ ) => {
-  if (fmt === 'b') {
-    return val.toString(2);
+const format = (fmt, val, len) => {
+  const m1 = fmt.match(/^%(?<sign>[s])?(?<radix>[bodhH])$/);
+  len = BigInt(len);
+  if (m1) {
+    const p = m1.groups;
+    const radix = ({b: 2, o: 8, d: 10, h: 16, H: 16})[p.radix];
+    if (p.sign === 's') {
+      const sign = (val >> (len - 1n)) & 1n;
+      if (sign) {
+        val = val - (2n ** len);
+      }
+    }
+    let res = val.toString(radix);
+    if (p.radix === 'H') {
+      return res.toUpperCase();
+    }
+    return res;
   }
-  if (fmt === 'o') {
-    return val.toString(8);
+  const m2 = fmt.match(/^%A$/);
+  if (m2) {
+    let txtRes = '';
+    for (let i = 0n; i < len; i += 8n) {
+      txtRes = String.fromCharCode(Number((val >> i) & 0xffn)) + txtRes;
+    }
+    return txtRes;
   }
-  if (fmt === 'd') {
-    return val.toString(10);
-  }
-  if (fmt === 'h') {
-    return val.toString(16);
-  }
-
-  return val.toString();
 };
 
 

test/format.js

@@ -4,10 +4,29 @@ const {expect} = require('chai');
 const format = require('../lib/format.js');
 
 const tt = [
-  {fmt: 'b', val: 12345678n, len: 16, res: '101111000110000101001110'},
-  {fmt: 'o', val: 12345678n, len: 16, res: '57060516'},
-  {fmt: 'd', val: 12345678n, len: 16, res: '12345678'},
-  {fmt: 'h', val: 12345678n, len: 16, res: 'bc614e'}
+  {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'},
+  {fmt: '%sd',   val: 5n, len: 3, res: '-3'},
+  {fmt: '%sh',   val: 5n, len: 3, res: '-3'},
+
+  {fmt: '%sb',   val: 12345678n, len: 24, res: '-10000111001111010110010'},
+  {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'},
 ];
 
 describe('format', () => {