version bump 1.2.0: ESM version

Fixes #3 h/t @75lb
2018-09-03 23:35:36 -04:00 · 2018-09-03 23:35:36 -04:00 · e1e33f9cb6
commit e1e33f9cb6
parent dc687f5ed0
18 changed files with 1411 additions and 50 deletions
--- a/.spelling
+++ b/.spelling
@ -0,0 +1,40 @@
+# printj (C) 2016-present SheetJS -- http://sheetjs.com
+SheetJS
+printj
+printf
+
+# printf-related terms
+16-bit
+32-bit
+52-bit
+64-bit
+base-10
+fmt
+
+# Third-party
+AltiVec
+FreeBSD
+glibc
+libc
+nodejs
+npm
+unicode
+
+# Other terms
+CommonJS
+NaN
+UTF-16
+accessor
+bitwise
+codepages
+conformant
+errno
+falsy
+runtime
+trigraphs
+truthy
+typeof
+valueOf
+variadic
+whitespace
+
--- a/4
+++ b/4
@ -9,6 +9,7 @@ ULIB=$(shell echo $(LIB) | tr a-z A-Z)
 DEPS=$(sort $(wildcard bits/*.js))
 TARGET=$(LIB).js
 FLOWTARGET=$(LIB).flow.js
+MJSTARGET=$(LIB).mjs
 FLOWTGTS=$(TARGET) $(AUXTARGETS)
 CLOSURE=/usr/local/lib/node_modules/google-closure-compiler/compiler.jar

@ -26,6 +27,7 @@ $(FLOWTGTS): %.js : %.flow.js

 $(FLOWTARGET): $(DEPS) lib
 	cp lib/$(REQS).js $(FLOWTARGET)
+	cp lib/$(REQS).mjs $(MJSTARGET)

 bits/01_version.js: package.json
 	echo "$(ULIB).version = '"`grep version package.json | awk '{gsub(/[^0-9a-z\.-]/,"",$$2); print $$2}'`"';" > $@
@ -75,7 +77,7 @@ fullint: lint old-lint tslint flow mdlint ## Run all checks

 .PHONY: lint
 lint: $(TARGET) ## Run eslint checks
-	@eslint --ext .js,.njs,.json,.html,.htm $(TARGET) $(AUXTARGETS) $(CMDS) $(HTMLLINT) package.json bower.json
+	@eslint --ext .js,.njs,.json,.html,.htm $(TARGET) $(AUXTARGETS) $(CMDS) $(HTMLLINT) package.json
 	if [ -e $(CLOSURE) ]; then java -jar $(CLOSURE) $(FLOWTARGET) --jscomp_warning=reportUnknownTypes >/dev/null; fi

 .PHONY: old-lint
--- a/README.md
+++ b/README.md
@ -11,6 +11,67 @@ A self-contained specification of the printf format string is included below in
 [support against various printf implementations](#support-summary)


+## Table of Contents
+
+<details>
+	<summary><b>Table of Contents</b> (click to show)</summary>
+
+<!-- toc -->
+
+  * [Installation](#installation)
+  * [Usage](#usage)
+  * [Testing](#testing)
+  * [License](#license)
+  * [Badges](#badges)
+- [printf format string specification](#printf-format-string-specification)
+    + [Original C Interface](#original-c-interface)
+    + [JS and C strings](#js-and-c-strings)
+    + [JS Interface](#js-interface)
+  * [Specifier heritage and regular expression](#specifier-heritage-and-regular-expression)
+  * [Conversion Specifier Quick Reference Table](#conversion-specifier-quick-reference-table)
+  * [Parameter Selection](#parameter-selection)
+  * [Dynamic Specifiers](#dynamic-specifiers)
+- [C Data Model](#c-data-model)
+    + [Integer Types](#integer-types)
+    + [Character and String Types](#character-and-string-types)
+    + [Floating Point Number Types](#floating-point-number-types)
+  * [Implementation](#implementation)
+- [Integer Conversions](#integer-conversions)
+  * [Restricting Integer Values](#restricting-integer-values)
+  * [Length Specifiers for Integer Conversions](#length-specifiers-for-integer-conversions)
+  * [Rendering Unsigned Integers in Base 10 ("u" and "U" conversions)](#rendering-unsigned-integers-in-base-10-u-and-u-conversions)
+  * [Rendering Unsigned Integers in Base 8 ("o" and "O" conversions)](#rendering-unsigned-integers-in-base-8-o-and-o-conversions)
+  * [Rendering Unsigned Integers in Base 16 ("x" and "X" conversions)](#rendering-unsigned-integers-in-base-16-x-and-x-conversions)
+  * [Rendering Signed Integers in Base 10 ("d" "i" and "D" conversions)](#rendering-signed-integers-in-base-10-d-i-and-d-conversions)
+- [Floating Point Conversions](#floating-point-conversions)
+  * [Infinity, NaN, and Negative Zero](#infinity-nan-and-negative-zero)
+  * [Exponential Form ("e" and "E" conversions)](#exponential-form-e-and-e-conversions)
+  * [Standard Form ("f" and "F" conversions)](#standard-form-f-and-f-conversions)
+  * [Value-dependent Form ("g" and "G" conversions)](#value-dependent-form-g-and-g-conversions)
+  * [Hex-Mantissa Decimal-Binary-Exponent Form ("a" and "A" conversions)](#hex-mantissa-decimal-binary-exponent-form-a-and-a-conversions)
+- [Character Conversions](#character-conversions)
+  * [Rendering Strings ("s" and "S" conversions)](#rendering-strings-s-and-s-conversions)
+  * [Rendering Characters ("c" and "C" conversions)](#rendering-characters-c-and-c-conversions)
+- [Non-Numeric Conversions](#non-numeric-conversions)
+  * [The literal "%" symbol ("%" conversion)](#the-literal-%25-symbol-%25-conversion)
+  * [Interpreting and Rendering Pointers ("p" conversion)](#interpreting-and-rendering-pointers-p-conversion)
+  * [Extracting length of a partial conversion ("n" conversion)](#extracting-length-of-a-partial-conversion-n-conversion)
+  * [Error messages ("m" conversion)](#error-messages-m-conversion)
+- [Extensions](#extensions)
+  * [Rendering Boolean Values ("y" and "Y" conversions)](#rendering-boolean-values-y-and-y-conversions)
+  * [Rendering JSON ("J" conversion)](#rendering-json-j-conversion)
+  * [JS typeof and valueOf ("T" and "V" conversion)](#js-typeof-and-valueof-t-and-v-conversion)
+  * [Rendering Unsigned Integers in Base 2 ("b" and "B" conversions)](#rendering-unsigned-integers-in-base-2-b-and-b-conversions)
+- [Miscellaneous Notes](#miscellaneous-notes)
+  * [Format Characters](#format-characters)
+  * [JS and C strings](#js-and-c-strings-1)
+  * [Browser Deviations](#browser-deviations)
+  * [Support Summary](#support-summary)
+
+<!-- tocstop -->
+
+</details>
+
 ## Installation

 With [npm](https://www.npmjs.org/package/printj):
@ -30,9 +91,8 @@ The browser exposes a variable `PRINTJ`
 When installed globally, npm installs a script `printj` that renders the format
 string with the given arguments.  Running the script with `-h` displays help.

-The script will manipulate `module.exports` if available (e.g. in a CommonJS
-`require` context).  This is not always desirable.  To prevent the behavior,
-define `DO_NOT_EXPORT_PRINTJ`
+The script will manipulate `module.exports` if available.  This is not always
+desirable.  To prevent the behavior, define `DO_NOT_EXPORT_PRINTJ`

 ## Usage

@ -125,8 +185,8 @@ but have different interfaces reflecting different input and output behaviors.
 Some functions have wide variants that use wide `wchar_t *` strings rather than
 normal C `char *`.  The following variants are required by the POSIX spec:

-|  function  | max length |  output destination   | vintage |  wide ver  |
-|------------|------------|-----------------------|---------|------------|
+|  function  | max length |  output destination   | vintage |  wide form |
+|:-----------|:-----------|:----------------------|:--------|:-----------|
 | `printf`   | unbounded  | standard output       | K&R     | `wprintf`  |
 | `fprintf`  | unbounded  | stream (`FILE *`)     | K&R     | `fwprintf` |
 | `sprintf`  | unbounded  | string (`char *`)     | K&R     | `swprintf` |
@ -185,7 +245,7 @@ various string functions are included at the end of the document.

 ## Specifier heritage and regular expression

-Note: The regular expressions follow perl `/x` style.  Whitespace characters
+Note: The regular expressions follow Perl `/x` style.  Whitespace characters
 outside of character classes are ignored.  `#` is a comment character and every
 character until the end of the line is ignored.  To convert to a standard regex:

@ -298,7 +358,7 @@ This implementation explicitly does not support certain non-standard extensions:
 | `i` | integral | cast to C `int`,   standard form decimal (alias of `d`)     |
 | `J` | extended | prints objects using JSON or `util.inspect`                 |
 | `m` |   misc   | prints info about Error objects (JS equivalent of `errno`)  |
-| `n` |   misc   | do not print! stores number of chars written to arg `.len`  |
+| `n` |   misc   | do not print! store number of chars written to `.len` field |
 | `o` | integral | cast to C `unsigned int`,   standard form octal             |
 | `O` | integral | cast to C `unsigned long`,  standard form octal             |
 | `p` |   misc   | print `"l"` field of object (fake pointer)                  |
@ -323,8 +383,8 @@ printf("Count to 3: %d %d %d", 1, 2, 3); // Count to 3: 1 2 3
 ```

 POSIX `printf` permits explicit argument selection, bypassing the standard
-behavior of using the arguments in order.  To select the `n`-th argument, use
-`n$` immediately after the `%` token to select an argument for the conversion:
+behavior of consuming arguments in order. To specify the argument at position
+`n`, use `n$` immediately after the `%` token:

 ```C
 printf("%d %d %d",       1, 2, 3);        // 1 2 3 (implicit order 1, 2, 3 )
@ -463,11 +523,11 @@ Numerous "C data models", specifying the bit/byte sizes of the various types,
 have been and continue to be used.  For example, OSX and other modern 64-bit
 UNIX flavors use the "LP64" C data model.  64-bit Windows currently uses the
 "LLP64" model.  32-bit systems generally use the "ILP32" model.  The 8-bit byte
-sizes for the various types under the various models are defined in ctypes.json
+sizes for the data types under the various models are defined in `ctypes.json`
 in the `Models` object as per the following table:

-| type        | ctypes.json | LP64 | ILP32 | LLP64 |
-|-------------|-------------|-----:|------:|------:|
+| type        | JSON key    | LP64 | ILP32 | LLP64 |
+|:------------|:------------|-----:|------:|------:|
 | `char`      | `char`      |   1  |    1  |    1  |
 | `short`     | `short`     |   2  |    2  |    2  |
 | `int`       | `int`       |   4  |    4  |    4  |
@ -555,16 +615,16 @@ is signed or unsigned according to the conversion specifier.  If a length is
 specified, it overrides the implied length of the conversion.  The following
 table describes the behavior of this implementation:

-| implied C type                      | ctypes.json | length | conv default |
-|:------------------------------------|:------------|:------:|:-------------|
-| `int` or `unsigned int`             | `int`       | (none) | d i o u x X  |
-| `char` or `unsigned char`           | `char`      |   hh   |
-| `short` or `unsigned short`         | `short`     |    h   |
-| `long` or `unsigned long`           | `long`      |    l   | D U O        |
-| `long long` or `unsigned long long` | `longlong`  | L ll q |
-| `intmax_t` or `uintmax_t`           | `intmax_t`  |    j   |
-| `size_t` or `ssize_t`               | `size_t`    |   z Z  |
-| `ptrdiff_t` or unsigned variant     | `ptrdiff_t` |    t   |
+| implied C type               | JSON key    |  length  | conversion default |
+|:-----------------------------|:------------|:--------:|:-------------------|
+| `[unsigned] int`             | `int`       |  (none)  | `d i o u x X`      |
+| `[unsigned] char`            | `char`      |   `hh`   |
+| `[unsigned] short`           | `short`     |    `h`   |
+| `[unsigned] long`            | `long`      |    `l`   | `D U O`            |
+| `[unsigned] long long`       | `longlong`  | `L ll q` |
+| `intmax_t` or `uintmax_t`    | `intmax_t`  |    `j`   |
+| `size_t` or `ssize_t`        | `size_t`    |   `z Z`  |
+| `ptrdiff_t` or unsigned form | `ptrdiff_t` |    `t`   |

 ## Rendering Unsigned Integers in Base 10 ("u" and "U" conversions)

@ -615,7 +675,7 @@ JS recognizes a few special IEEE754 values, as described in the following table:
 |------------:|:--------------|:-----------------------------------------------|
 |  `Infinity` | `1./0.`       | Positive limiting value `lim{x->0+} 1/x`       |
 | `-Infinity` | `-1./0.`      | Negative limiting value `lim{x->0+} -1/x`      |
-|       `NaN` | `0./0.`       | Placeholder for "not-a-number" e.g. `0./0.`    |
+|       `NaN` | `0./0.`       | Placeholder for "not-a-number" such as `0./0.` |
 |       `-0.` | `-1/Infinity` | Negative limiting value `lim{x->0-} x`         |

 JS `Number` methods render different strings from the POSIX spec:
@ -625,7 +685,7 @@ JS `Number` methods render different strings from the POSIX spec:
 |  `Infinity` |  `"inf"  "INF"` or  `"infinity"  "INFINITY"`  |  `"Infinity"` |
 | `-Infinity` | `"-inf" "-INF"` or `"-infinity" "-INFINITY"`  | `"-Infinity"` |
 |       `NaN` | `"[-]nan" "[-]NAN"` w/opt parenthesized chars |       `"NaN"` |
-|       `-0.` | uses negative sign (e.g. `"-0"` under `"%f"`) | same as `+0.` |
+|       `-0.` | uses negative sign (`"-0"` under `"%f"`)      | same as `+0.` |

 This implementation performs the required adjustments.

@ -656,12 +716,12 @@ The final form (exponential or standard) is determined based on the value.  The
 threshold is different from the JS `toString` / `toPrecision` thresholds and
 depends on the specified precision as well as the base-10 exponent:

-|   Value   |  `"%.3g"`  | `toPrecision(3)` |
-|----------:|:-----------|:-----------------|
-| 1.2345e-4 | `0.000123` | `0.000123`       |
-| 1.2345e-5 | `1.23e-05` | `0.0000123`      |
-| 1.2345e-6 | `1.23e-06` | `0.00000123`     |
-| 1.2345e-7 | `1.23e-07` | `1.23e-7`        |
+|   Value     |  `"%.3g"`  | `toPrecision(3)` |
+|------------:|:-----------|:-----------------|
+| `1.2345e-4` | `0.000123` | `0.000123`       |
+| `1.2345e-5` | `1.23e-05` | `0.0000123`      |
+| `1.2345e-6` | `1.23e-06` | `0.00000123`     |
+| `1.2345e-7` | `1.23e-07` | `1.23e-7`        |

 According to JS spec, `toPrecision` uses standard form when `precision > E` and
 `E >= -6`.  For printf standard form is used when `precision > E` and `E >= -4`.
@ -673,20 +733,20 @@ the exponent expression, and radix of the exponent expression.  The standard
 exponential form uses decimal for all three parts.  For base 16, there are quite
 a few reasonable combinations.  Consider the value `1.234567e-80`:

-| Mant | Exp Base | Radix-10 (sigil `";"`) | Radix-16 (sigil `";"`) |
-|:----:|:--------:|:-----------------------|:-----------------------|
-|  10  |    10    | `1.234567;-80`         | `1.234567;-50`         |
-|  16  |    10    | `1.3c0c9539b8887;-80`  | `1.3c0c9539b8887;-50`  |
-|  16  |    16    | `5.daf8c8f5f4104;-67`  | `5.daf8c8f5f4104;-43`  |
-|  16  |     4    | `1.76be323d7d041;-133` | `1.76be323d7d041;-85`  |
-|  16  |     2    | `1.76be323d7d041;-266` | `1.76be323d7d041;-10a` |
+| Mantissa | Exp Base | Radix 10 (sigil `";"`) | Radix 16 (sigil `";"`) |
+|:--------:|:--------:|:-----------------------|:-----------------------|
+|    10    |    10    | `1.234567;-80`         | `1.234567;-50`         |
+|    16    |    10    | `1.3c0c9539b8887;-80`  | `1.3c0c9539b8887;-50`  |
+|    16    |    16    | `5.daf8c8f5f4104;-67`  | `5.daf8c8f5f4104;-43`  |
+|    16    |     4    | `1.76be323d7d041;-133` | `1.76be323d7d041;-85`  |
+|    16    |     2    | `1.76be323d7d041;-266` | `1.76be323d7d041;-10a` |

 POSIX `"%a"` uses a hex mantissa (16), decimal exponent radix (10), and binary
 exponent base (2).  The general normalized form requires that the integral part
 of the mantissa to exceed 0 and not to exceed `exponent base - 1` except in the
 special case of `0`.  The sigil is `p` and exponent sign is always used.

-JS `num.toString(radix)` is implementation-dependent for valid non-10 radices
+JS `num.toString(radix)` is implementation-dependent for radices other than 10
 (`2-9, 11-36`).  IE uses hex-mantissa decimal-hex-exponent form when the
 absolute value of the base-2 exponent exceeds 60.  Otherwise, IE uses an exact
 standard hexadecimal form.  Chrome, Safari and other browsers always use the
--- a/bits/00_header.js
+++ b/bits/00_header.js
@ -4,6 +4,11 @@
 /*exported PRINTJ */
 /*:: declare var DO_NOT_EXPORT_PRINTJ:?boolean; */
 /*:: declare function define(cb:()=>any):void; */
+#ifdef USE_ESM
+var PRINTJ/*:PRINTJModule*/ = /*::(*/{}/*:: :any)*/;
+#include "01_version.js"
+export const version = PRINTJ.version;
+#else
 var PRINTJ/*:PRINTJModule*/;
 (function (factory/*:(a:any)=>void*/)/*:void*/ {
 	/*jshint ignore:start */
@ -27,3 +32,4 @@ var PRINTJ/*:PRINTJModule*/;
 	/*jshint ignore:end */
 }(function(PRINTJ/*:PRINTJModule*/) {
 #include "01_version.js"
+#endif
--- a/bits/01_version.js
+++ b/bits/01_version.js
@ -1 +1 @@
-PRINTJ.version = '1.1.2';
+PRINTJ.version = '1.2.0';
--- a/bits/50_doit.js
+++ b/bits/50_doit.js
@ -1,10 +1,13 @@
 #include "30_ctypes.js"
 #include "40_macros.js"
+#ifdef USE_ESM
+var u_inspect/*:(o:any)=>string*/ = JSON.stringify;
+#else
 /*:: var util = require('util'); */
 /*global process:true, util:true, require:true */
 if(typeof process !== 'undefined' && !!process.versions && !!process.versions.node) util=require("util");
 var u_inspect/*:(o:any)=>string*/ = (typeof util != 'undefined') ? util.inspect : JSON.stringify;
-
+#endif

 function doit(t/*:ParsedFmt*/, args/*:Array<any>*/)/*:string*/ {
 	var o/*:Array<string>*/ = [];
--- a/bits/54_convmisc.js
+++ b/bits/54_convmisc.js
@ -35,7 +35,7 @@
 			/* boolean (extension) */
 			case /*Y*/  89:
 			case /*y*/ 121:
-				O = Boolean(arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
+				O = (arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
 				if(c == /*Y*/ 89) O = O.toUpperCase();
 				PREC_STR(O, prec)
 				WIDTH(O, width, flags)
--- a/bits/99_esmfoot.js
+++ b/bits/99_esmfoot.js
@ -0,0 +1 @@
+export { sprintf, vsprintf };
--- a/bits/Makefile
+++ b/bits/Makefile
@ -2,8 +2,8 @@ ifndef OUTDIR
 	OUTDIR=$(PWD)/lib
 endif

-JSFILES=$(wildcard *.js)
-LIBS=$(filter-out $(wildcard [0-9]*_*.js),$(wildcard *.js))
+JSFILES=$(wildcard *.js) $(wildcard *.mjs)
+LIBS=$(filter-out $(wildcard [0-9]*_*.js),$(JSFILES))

 OUTLIBS=$(patsubst %,$(OUTDIR)/%,$(LIBS))

--- a/bits/loop_code.mjs
+++ b/bits/loop_code.mjs
@ -0,0 +1,8 @@
+#define USE_ESM
+#include "00_header.js"
+#define USE_LOOP
+#define USE_CODE
+#include "10_tokenize.js"
+#include "50_doit.js"
+#include "80_wrapper.js"
+#include "99_esmfoot.js"
--- a/lib/loop_code.mjs
+++ b/lib/loop_code.mjs
@ -0,0 +1,582 @@
+/* printj.js (C) 2016-present SheetJS -- http://sheetjs.com */
+/* vim: set ts=2: */
+/*jshint sub:true, eqnull:true */
+/*exported PRINTJ */
+/*:: declare var DO_NOT_EXPORT_PRINTJ:?boolean; */
+/*:: declare function define(cb:()=>any):void; */
+
+var PRINTJ/*:PRINTJModule*/ = /*::(*/{}/*:: :any)*/;
+
+PRINTJ.version = '1.2.0';
+
+export const version = PRINTJ.version;
+
+function tokenize(fmt/*:string*/)/*:ParsedFmt*/ {
+	var out/*:ParsedFmt*/ = [];
+	var start/*:number*/ = 0;
+
+	var i/*:number*/ = 0;
+	var infmt/*:boolean*/ = false;
+	var fmtparam/*:string*/ = "", fmtflags/*:string*/ = "", fmtwidth/*:string*/ = "", fmtprec/*:string*/ = "", fmtlen/*:string*/ = "";
+
+	var c/*:number*/ = 0;
+
+	var L/*:number*/ = fmt.length;
+
+	for(; i < L; ++i) {
+		c = fmt.charCodeAt(i);
+		if(!infmt) {
+
+			if(c !== 37) continue;
+
+			if(start < i) out.push(["L", fmt.substring(start, i)]);
+			start = i;
+			infmt = true;
+			continue;
+		}
+
+		if(c >= 48 && c < 58)	{
+				if(fmtprec.length) fmtprec += String.fromCharCode(c);
+				else if(c == 48 && !fmtwidth.length) fmtflags += String.fromCharCode(c);
+				else fmtwidth += String.fromCharCode(c);
+		} else switch(c) {
+			/* positional */
+			case 36:
+				if(fmtprec.length) fmtprec += "$";
+				else if(fmtwidth.charAt(0) == "*") fmtwidth += "$";
+				else { fmtparam = fmtwidth + "$"; fmtwidth = ""; }
+				break;
+
+			/* flags */
+			case 39: fmtflags += "'"; break;
+			case 45: fmtflags += "-"; break;
+			case 43: fmtflags += "+"; break;
+			case 32: fmtflags += " "; break;
+			case 35: fmtflags += "#"; break;
+
+			/* width and precision */
+			case 46: fmtprec = "."; break;
+			case 42:
+				if(fmtprec.charAt(0) == ".") fmtprec += "*";
+				else fmtwidth += "*";
+				break;
+
+			/* length */
+			case 104:
+			case 108:
+				if(fmtlen.length > 1) throw "bad length " + fmtlen + String(c);
+				fmtlen += String.fromCharCode(c);
+				break;
+
+			case  76:
+			case 106:
+			case 122:
+			case 116:
+			case 113:
+			case  90:
+			case 119:
+				if(fmtlen !== "") throw "bad length " + fmtlen + String.fromCharCode(c);
+				fmtlen = String.fromCharCode(c);
+				break;
+
+			case 73:
+				if(fmtlen !== "") throw "bad length " + fmtlen + 'I';
+				fmtlen = 'I';
+				break;
+
+			/* conversion */
+			case 100:
+			case 105:
+			case 111:
+			case 117:
+			case 120:
+			case 88:
+			case 102:
+			case 70:
+			case 101:
+			case 69:
+			case 103:
+			case 71:
+			case 97:
+			case 65:
+			case 99:
+			case 67:
+			case 115:
+			case 83:
+			case 112:
+			case 110:
+			case 68:
+			case 85:
+			case 79:
+			case 109:
+			case 98:
+			case 66:
+			case 121:
+			case 89:
+			case 74:
+			case 86:
+			case 84:
+			case 37:
+				infmt = false;
+				if(fmtprec.length > 1) fmtprec = fmtprec.substr(1);
+				out.push([String.fromCharCode(c), fmt.substring(start, i+1), fmtparam, fmtflags, fmtwidth, fmtprec, fmtlen]);
+				start = i+1;
+				fmtlen = fmtprec = fmtwidth = fmtflags = fmtparam = "";
+				break;
+			default:
+				throw new Error("Invalid format string starting with |" + fmt.substring(start, i+1) + "|");
+		}
+
+	}
+
+	if(start < fmt.length) out.push(["L", fmt.substring(start)]);
+	return out;
+}
+
+//#define PAD_(x,c) (x >= 0 ? new Array(((x)|0) + 1).join((c)) : "")
+var padstr/*:{[s:string]:string}*/ = {
+	" ": "                                 ",
+	"0": "000000000000000000000000000000000",
+	"7": "777777777777777777777777777777777",
+	"f": "fffffffffffffffffffffffffffffffff"
+};
+
+var u_inspect/*:(o:any)=>string*/ = JSON.stringify;
+
+function doit(t/*:ParsedFmt*/, args/*:Array<any>*/)/*:string*/ {
+	var o/*:Array<string>*/ = [];
+	var argidx/*:number*/ = 0, idx/*:number*/ = 0;
+	var Vnum/*:number*/ = 0;
+	var pad/*:string*/ = "";
+	for(var i/*:number*/ = 0; i < t.length; ++i) {
+		var m/*:ParsedEntry*/ = t[i], c/*:number*/ = (m[0]/*:string*/).charCodeAt(0);
+		/* m order: conv full param flags width prec length */
+
+		if(c === /*L*/ 76) { o.push(m[1]); continue; }
+		if(c === /*%*/ 37) { o.push("%"); continue; }
+
+		var O/*:string*/ = "";
+		var isnum/*:number*/ = 0, radix/*:number*/ = 10, bytes/*:number*/ = 4, sign/*:boolean*/ = false;
+
+		/* flags */
+		var flags/*:string*/ = m[3]||"";
+		var alt/*:boolean*/ = flags.indexOf("#") > -1;
+
+		/* position */
+		if(m[2]) argidx = parseInt(m[2])-1;
+		/* %m special case */
+		else if(c === /*m*/ 109 && !alt) { o.push("Success"); continue; }
+
+		/* grab width */
+		var width =  0; if(m[ 4] != null && m[ 4].length > 0) { if(m[ 4].charAt(0) !== '*') width = parseInt(m[ 4], 10); else if(m[ 4].length === 1) width = args[idx++]; else width = args[parseInt(m[ 4].substr(1), 10)-1]; }
+
+		/* grab precision */
+		var prec =  -1; if(m[ 5] != null && m[ 5].length > 0) { if(m[ 5].charAt(0) !== '*') prec = parseInt(m[ 5], 10); else if(m[ 5].length === 1) prec = args[idx++]; else prec = args[parseInt(m[ 5].substr(1), 10)-1]; }
+
+		/* position not specified */
+		if(!m[2]) argidx = idx++;
+
+		/* grab argument */
+		var arg/*:any*/ = args[argidx];
+
+		/* grab length */
+		var len/*:string*/ = m[6] || "";
+
+		switch(c) {
+			/* str cCsS */
+
+			case /*S*/  83:
+			case /*s*/ 115:
+				/* only valid flag is "-" for left justification */
+				O = String(arg);
+				if( prec >= 0) O = O.substr(0,  prec);
+				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
+				break;
+
+			/* first char of string or convert */
+			case /*C*/  67:
+			case /*c*/  99:
+				switch(typeof arg) {
+					case "number":
+						var cc/*:number*/ = arg;
+						if(c == 67 || len.charCodeAt(0) === /*l*/ 108) {  cc &= 0xFFFFFFFF; O = String.fromCharCode( cc); }
+						else {  cc &= 0xFF; O = String.fromCharCode( cc); }
+						break;
+					case "string": O = /*::(*/arg/*:: :string)*/.charAt(0); break;
+					default: O = String(arg).charAt(0);
+				}
+				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
+				break;
+
+			/* int diDuUoOxXbB */
+
+			/* signed integer */
+			case /*D*/  68: bytes = 8;
+			/* falls through */
+			case /*d*/ 100:
+			case /*i*/ 105: isnum = -1; sign = true; break;
+
+			/* unsigned integer */
+			case /*U*/  85: bytes = 8;
+			/* falls through */
+			case /*u*/ 117: isnum = -1; break;
+
+			/* unsigned octal */
+			case /*O*/  79: bytes = 8;
+			/* falls through */
+			case /*o*/ 111: isnum = -1; radix = (8); break;
+
+			/* unsigned hex */
+			case /*x*/ 120: isnum = -1; radix = (-16); break;
+			case /*X*/  88: isnum = -1; radix = (16); break;
+
+			/* unsigned binary (extension) */
+			case /*B*/  66: bytes = 8;
+			/* falls through */
+			case /*b*/  98: isnum = -1; radix = (2); break;
+
+			/* flt fegFEGaA */
+
+			/* floating point logic */
+			case /*F*/  70:
+			case /*f*/ 102: isnum = (1); break;
+
+			case /*E*/  69:
+			case /*e*/ 101: isnum = (2); break;
+
+			case /*G*/  71:
+			case /*g*/ 103: isnum = (3); break;
+
+			/* floating hex */
+			case /*A*/  65:
+			case /*a*/  97: isnum = (4); break;
+
+			/* misc pnmJVTyY */
+
+			/* JS has no concept of pointers so interpret the `l` key as an address */
+			case /*p*/ 112:
+				Vnum = typeof arg == "number" ? arg : arg ? Number(arg.l) : -1;
+				if(isNaN(Vnum)) Vnum = -1;
+				if(alt) O = Vnum.toString(10);
+				else {
+					Vnum = Math.abs(Vnum);
+					O = "0x" + Vnum.toString(16).toLowerCase();
+				}
+				break;
+
+			/* store length in the `len` key */
+			case /*n*/ 110:
+				if(arg) { arg.len=0; for(var oo/*:number*/ = 0; oo < o.length; ++oo) arg.len += o[oo].length; }
+				continue;
+
+			/* process error */
+			case /*m*/ 109:
+				if(!(arg instanceof Error)) O = "Success";
+				else if(arg.message) O = arg.message;
+				else if(arg.errno) O = "Error number " + arg.errno;
+				else O = "Error " + String(arg);
+				break;
+
+			/* JS-specific conversions (extension) */
+			case /*J*/  74: O = (alt ? u_inspect : JSON.stringify)(arg); break;
+			case /*V*/  86: O = arg == null ? "null" : String(arg.valueOf()); break;
+			case /*T*/  84:
+				if(alt) { /* from '[object %s]' extract %s */
+					O = Object.prototype.toString.call(arg).substr(8);
+					O = O.substr(0, O.length - 1);
+				} else O = typeof arg;
+				break;
+
+			/* boolean (extension) */
+			case /*Y*/  89:
+			case /*y*/ 121:
+				O = (arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
+				if(c == /*Y*/ 89) O = O.toUpperCase();
+				if( prec >= 0) O = O.substr(0,  prec);
+				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
+				break;
+
+		}
+
+		if(width < 0) { width = -width; flags += "-"; }
+
+		if(isnum == -1) {
+
+			Vnum = Number(arg);
+
+			/* parse byte length field */
+
+			switch(len) {
+				/* char */
+				case "hh": { bytes = 1; } break;
+				/* short */
+				case "h":  { bytes = 2; } break;
+
+				/* long */
+				case "l":  { if(bytes == 4) bytes = 8; } break;
+
+				/* long long */
+				case "L":
+				case "q":
+				case "ll": { if(bytes == 4) bytes = 8; } break;
+
+				/* intmax_t */
+				case "j":  { if(bytes == 4) bytes = 8; } break;
+
+				/* ptrdiff_t */
+				case "t":  { if(bytes == 4) bytes = 8; } break;
+
+				/* size_t */
+				case "z":
+				case "Z":  { if(bytes == 4) bytes = 8; } break;
+
+				/* CRT size_t or ptrdiff_t */
+				case "I":
+
+					{ if(bytes == 4) bytes = 8; }
+
+					break;
+
+				/* CRT wchar_t */
+				case "w": break;
+			}
+
+			/* restrict value */
+
+			switch(bytes) {
+				case 1: Vnum = (Vnum & 0xFF); if(sign && (Vnum >  0x7F)) Vnum -= (0xFF + 1); break;
+				case 2: Vnum = (Vnum & 0xFFFF); if(sign && (Vnum >  0x7FFF)) Vnum -= (0xFFFF + 1); break;
+				case 4: Vnum = sign ? (Vnum | 0) : (Vnum >>> 0); break;
+				default: Vnum = isNaN(Vnum) ? 0 : Math.round(Vnum); break;
+			}
+
+			/* generate string */
+			if(bytes > 4 && Vnum < 0 && !sign) {
+				if(radix == 16 || radix == -16) {
+					O = (Vnum>>>0).toString(16);
+					Vnum = Math.floor((Vnum - (Vnum >>> 0)) / Math.pow(2,32));
+					O = (Vnum>>>0).toString(16) + (8 - O.length >= 0 ? padstr[ "0"].substr(0,8 - O.length) : "") + O;
+					O = (16 - O.length >= 0 ? padstr[ "f"].substr(0,16 - O.length) : "") + O;
+					if(radix == 16) O = O.toUpperCase();
+				} else if(radix == 8) {
+					O = (Vnum>>>0).toString(8);
+					O = (10 - O.length >= 0 ? padstr[ "0"].substr(0,10 - O.length) : "") + O;
+					Vnum = Math.floor((Vnum - ((Vnum >>> 0)&0x3FFFFFFF)) / Math.pow(2,30));
+					O = (Vnum>>>0).toString(8) + O.substr(O.length - 10);
+					O = O.substr(O.length - 20);
+					O = "1" + (21 - O.length >= 0 ? padstr[ "7"].substr(0,21 - O.length) : "") + O;
+				} else {
+					Vnum = (-Vnum) % 1e16;
+					var d1/*:Array<number>*/ = [1,8,4,4,6,7,4,4,0,7,3,7,0,9,5,5,1,6,1,6];
+					var di/*:number*/ = d1.length - 1;
+					while(Vnum > 0) {
+						if((d1[di] -= (Vnum % 10)) < 0) { d1[di] += 10; d1[di-1]--; }
+						--di; Vnum = Math.floor(Vnum / 10);
+					}
+					O = d1.join("");
+				}
+			} else {
+				if(radix === -16) O = Vnum.toString(16).toLowerCase();
+				else if(radix === 16) O = Vnum.toString(16).toUpperCase();
+				else O = Vnum.toString(radix);
+			}
+
+			/* apply precision */
+			if(prec ===0 && O == "0" && !(radix == 8 && alt)) O = ""; /* bail out */
+			else {
+				if(O.length < prec + (O.substr(0,1) == "-" ? 1 : 0)) {
+					if(O.substr(0,1) != "-") O = (prec - O.length >= 0 ? padstr[ "0"].substr(0,prec - O.length) : "") + O;
+					else O = O.substr(0,1) + (prec + 1 - O.length >= 0 ? padstr[ "0"].substr(0,prec + 1 - O.length) : "") + O.substr(1);
+				}
+
+				/* add prefix for # form */
+				if(!sign && alt && Vnum !== 0) switch(radix) {
+					case -16: O = "0x" + O; break;
+					case  16: O = "0X" + O; break;
+					case   8: if(O.charAt(0) != "0") O =  "0" + O; break;
+					case   2: O = "0b" + O; break;
+				}
+			}
+
+			/* add sign character */
+			if(sign && O.charAt(0) != "-") {
+				if(flags.indexOf("+") > -1) O = "+" + O;
+				else if(flags.indexOf(" ") > -1) O = " " + O;
+			}
+			/* width */
+			if(width > 0) {
+				if(O.length < width) {
+					if(flags.indexOf("-") > -1) {
+						O = O + ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "");
+					} else if(flags.indexOf("0") > -1 && prec < 0 && O.length > 0) {
+						if(prec > O.length) O = ((prec - O.length) >= 0 ? padstr[ "0"].substr(0,(prec - O.length)) : "") + O;
+						pad = ((width - O.length) >= 0 ? padstr[ (prec > 0 ? " " : "0")].substr(0,(width - O.length)) : "");
+						if(O.charCodeAt(0) < 48) {
+							if(O.charAt(2).toLowerCase() == "x") O = O.substr(0,3) + pad + O.substring(3);
+							else O = O.substr(0,1) + pad + O.substring(1);
+						}
+						else if(O.charAt(1).toLowerCase() == "x") O = O.substr(0,2) + pad + O.substring(2);
+						else O = pad + O;
+					} else {
+						O = ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "") + O;
+					}
+				}
+			}
+
+		} else if(isnum > 0) {
+
+			Vnum = Number(arg);
+			if(arg === null) Vnum = 0/0;
+			if(len == "L") bytes = 12;
+			var isf/*:boolean*/ = isFinite(Vnum);
+			if(!isf) { /* Infinity or NaN */
+				if(Vnum < 0) O = "-";
+				else if(flags.indexOf("+") > -1) O = "+";
+				else if(flags.indexOf(" ") > -1) O = " ";
+				O += (isNaN(Vnum)) ? "nan" : "inf";
+			} else {
+				var E/*:number*/ = 0;
+
+				if(prec == -1 && isnum != 4) prec = 6;
+
+				/* g/G conditional behavior */
+				if(isnum == 3) {
+					O = Vnum.toExponential(1);
+					E = +O.substr(O.indexOf("e") + 1);
+					if(prec === 0) prec = 1;
+					if(prec > E && E >= -4) { isnum = (11); prec = prec -(E + 1); }
+					else { isnum = (12); prec = prec - 1; }
+				}
+
+				/* sign: workaround for negative zero */
+				var sg/*:string*/ = (Vnum < 0 || 1/Vnum == -Infinity) ? "-" : "";
+				if(Vnum < 0) Vnum = -Vnum;
+
+				switch(isnum) {
+					/* f/F standard */
+					case 1: case 11:
+						if(Vnum < 1e21) {
+							O = Vnum.toFixed(prec);
+							if(isnum == 1) { if(prec===0 &&alt&& O.indexOf(".")==-1) O+="."; }
+							else if(!alt) O=O.replace(/(\.\d*[1-9])0*$/,"$1").replace(/\.0*$/,"");
+							else if(O.indexOf(".") == -1) O+= ".";
+							break;
+						}
+						O = Vnum.toExponential(20);
+						E = +O.substr(O.indexOf("e")+1);
+						O = O.charAt(0) + O.substr(2,O.indexOf("e")-2);
+						O = O + (E - O.length + 1 >= 0 ? padstr[ "0"].substr(0,E - O.length + 1) : "");
+						if(alt || (prec > 0 && isnum !== 11)) O = O + "." + (prec >= 0 ? padstr[ "0"].substr(0,prec) : "");
+						break;
+
+					/* e/E exponential */
+					case 2: case 12:
+						O = Vnum.toExponential(prec);
+						E = O.indexOf("e");
+						if(O.length - E === 3) O = O.substr(0, E+2) + "0" + O.substr(E+2);
+						if(alt && O.indexOf(".") == -1) O = O.substr(0,E) +"."+ O.substr(E);
+						else if(!alt && isnum == 12) O = O.replace(/\.0*e/, "e").replace(/\.(\d*[1-9])0*e/, ".$1e");
+						break;
+
+					/* a/A hex */
+					case 4:
+						if(Vnum===0){O= "0x0"+((alt||prec>0)?"."+(prec >= 0 ? padstr["0"].substr(0,prec) : ""):"")+"p+0"; break;}
+						O = Vnum.toString(16);
+						/* First char 0-9 */
+						var ac/*:number*/ = O.charCodeAt(0);
+						if(ac == 48) {
+							ac = 2; E = -4; Vnum *= 16;
+							while(O.charCodeAt(ac++) == 48) { E -= 4; Vnum *= 16; }
+							O = Vnum.toString(16);
+							ac = O.charCodeAt(0);
+						}
+
+						var ai/*:number*/ = O.indexOf(".");
+						if(O.indexOf("(") > -1) {
+							/* IE exponential form */
+							var am/*:?Array<any>*/ = O.match(/\(e(.*)\)/);
+							var ae/*:number*/ = am ? (+am[1]) : 0;
+							E += 4 * ae; Vnum /= Math.pow(16, ae);
+						} else if(ai > 1) {
+							E += 4 * (ai - 1); Vnum /= Math.pow(16, ai - 1);
+						} else if(ai == -1) {
+							E += 4 * (O.length - 1); Vnum /= Math.pow(16, O.length - 1);
+						}
+
+						/* at this point 1 <= Vnum < 16 */
+
+						if(bytes > 8) {
+							if(ac < 50) { E -= 3; Vnum *= 8; }
+							else if(ac < 52) { E -= 2; Vnum *= 4; }
+							else if(ac < 56) { E -= 1; Vnum *= 2; }
+							/* at this point 8 <= Vnum < 16 */
+						} else {
+							if(ac >= 56) { E += 3; Vnum /= 8; }
+							else if(ac >= 52) { E += 2; Vnum /= 4; }
+							else if(ac >= 50) { E += 1; Vnum /= 2; }
+							/* at this point 1 <= Vnum < 2 */
+						}
+
+						O = Vnum.toString(16);
+						if(O.length > 1) {
+							if(O.length > prec+2 && O.charCodeAt(prec+2) >= 56) {
+								var _f/*:boolean*/ = O.charCodeAt(0) == 102;
+								O = (Vnum + 8 * Math.pow(16, -prec-1)).toString(16);
+								if(_f && O.charCodeAt(0) == 49) E += 4;
+							}
+							if(prec > 0) {
+								O = O.substr(0, prec + 2);
+								if(O.length < prec + 2) {
+									if(O.charCodeAt(0) < 48) O = O.charAt(0) + ((prec + 2 - O.length) >= 0 ? padstr[ "0"].substr(0,(prec + 2 - O.length)) : "") + O.substr(1);
+									else O += ((prec + 2 - O.length) >= 0 ? padstr[ "0"].substr(0,(prec + 2 - O.length)) : "");
+								}
+							} else if(prec === 0) O = O.charAt(0) + (alt ? "." : "");
+						} else if(prec > 0) O = O + "." + (prec >= 0 ? padstr["0"].substr(0,prec) : "");
+						else if(alt) O = O + ".";
+						O = "0x" + O + "p" + (E>=0 ? "+" + E : E);
+						break;
+				}
+
+				if(sg === "") {
+					if(flags.indexOf("+") > -1) sg = "+";
+					else if(flags.indexOf(" ") > -1) sg = " ";
+				}
+
+				O = sg + O;
+			}
+
+			/* width */
+			if(width > O.length) {
+				if(flags.indexOf("-") > -1) {
+					O = O + ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "");
+				} else if(flags.indexOf("0") > -1 && O.length > 0 && isf) {
+					pad = ((width - O.length) >= 0 ? padstr[ "0"].substr(0,(width - O.length)) : "");
+					if(O.charCodeAt(0) < 48) {
+						if(O.charAt(2).toLowerCase() == "x") O = O.substr(0,3) + pad + O.substring(3);
+						else O = O.substr(0,1) + pad + O.substring(1);
+					}
+					else if(O.charAt(1).toLowerCase() == "x") O = O.substr(0,2) + pad + O.substring(2);
+					else O = pad + O;
+				} else {
+					O = ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "") + O;
+				}
+			}
+			if(c < 96) O = O.toUpperCase();
+
+		}
+
+		o.push(O);
+	}
+	return o.join("");
+}
+
+function vsprintf(fmt/*:string*/, args/*:Args*/)/*:string*/ { return doit(tokenize(fmt), args); }
+
+function sprintf(/*:: ...argz*/)/*:string*/ {
+	var args/*:Array<any>*/ = new Array(arguments.length - 1);
+	for(var i/*:number*/ = 0; i < args.length; ++i) args[i] = arguments[i+1];
+	return doit(tokenize(arguments[0]), args);
+}
+
+export { sprintf, vsprintf };
+
--- a/package.json
+++ b/package.json
@ -1,6 +1,6 @@
 {
 	"name": "printj",
-	"version": "1.1.2",
+	"version": "1.2.0",
 	"author": "sheetjs",
 	"description": "Pure-JS printf",
 	"keywords": [
@ -49,7 +49,7 @@
 		]
 	},
 	"homepage": "http://sheetjs.com/opensource",
-	"files": ["printj.js", "bin/printj.njs", "LICENSE", "README.md", "dist/*.js", "dist/*.map", "dist/LICENSE", "types/index.d.ts", "types/*.json"],
+	"files": ["printj.js", "printj.mjs", "bin/printj.njs", "LICENSE", "README.md", "dist/*.js", "dist/*.map", "dist/LICENSE", "types/index.d.ts", "types/*.json"],
 	"bugs": {
 		"url": "https://github.com/SheetJS/printj/issues"
 	},
--- a/printj.flow.js
+++ b/printj.flow.js
@ -4,6 +4,7 @@
 /*exported PRINTJ */
 /*:: declare var DO_NOT_EXPORT_PRINTJ:?boolean; */
 /*:: declare function define(cb:()=>any):void; */
+
 var PRINTJ/*:PRINTJModule*/;
 (function (factory/*:(a:any)=>void*/)/*:void*/ {
 	/*jshint ignore:start */
@ -27,7 +28,7 @@ var PRINTJ/*:PRINTJModule*/;
 	/*jshint ignore:end */
 }(function(PRINTJ/*:PRINTJModule*/) {

-PRINTJ.version = '1.1.2';
+PRINTJ.version = '1.2.0';

 function tokenize(fmt/*:string*/)/*:ParsedFmt*/ {
 	var out/*:ParsedFmt*/ = [];
@ -311,7 +312,7 @@ function doit(t/*:ParsedFmt*/, args/*:Array<any>*/)/*:string*/ {
 			/* boolean (extension) */
 			case /*Y*/  89:
 			case /*y*/ 121:
-				O = Boolean(arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
+				O = (arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
 				if(c == /*Y*/ 89) O = O.toUpperCase();
 				if( prec >= 0) O = O.substr(0,  prec);
 				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
--- a/printj.js
+++ b/printj.js
@ -25,7 +25,7 @@ var PRINTJ;
 	/*jshint ignore:end */
 }(function(PRINTJ) {

-PRINTJ.version = '1.1.2';
+PRINTJ.version = '1.2.0';

 function tokenize(fmt) {
 	var out = [];
@ -308,7 +308,7 @@ function doit(t, args) {
 			/* boolean (extension) */
 			case /*Y*/  89:
 			case /*y*/ 121:
-				O = Boolean(arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
+				O = (arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
 				if(c == /*Y*/ 89) O = O.toUpperCase();
 				if( prec >= 0) O = O.substr(0,  prec);
 				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
--- a/printj.mjs
+++ b/printj.mjs
@ -0,0 +1,582 @@
+/* printj.js (C) 2016-present SheetJS -- http://sheetjs.com */
+/* vim: set ts=2: */
+/*jshint sub:true, eqnull:true */
+/*exported PRINTJ */
+/*:: declare var DO_NOT_EXPORT_PRINTJ:?boolean; */
+/*:: declare function define(cb:()=>any):void; */
+
+var PRINTJ/*:PRINTJModule*/ = /*::(*/{}/*:: :any)*/;
+
+PRINTJ.version = '1.2.0';
+
+export const version = PRINTJ.version;
+
+function tokenize(fmt/*:string*/)/*:ParsedFmt*/ {
+	var out/*:ParsedFmt*/ = [];
+	var start/*:number*/ = 0;
+
+	var i/*:number*/ = 0;
+	var infmt/*:boolean*/ = false;
+	var fmtparam/*:string*/ = "", fmtflags/*:string*/ = "", fmtwidth/*:string*/ = "", fmtprec/*:string*/ = "", fmtlen/*:string*/ = "";
+
+	var c/*:number*/ = 0;
+
+	var L/*:number*/ = fmt.length;
+
+	for(; i < L; ++i) {
+		c = fmt.charCodeAt(i);
+		if(!infmt) {
+
+			if(c !== 37) continue;
+
+			if(start < i) out.push(["L", fmt.substring(start, i)]);
+			start = i;
+			infmt = true;
+			continue;
+		}
+
+		if(c >= 48 && c < 58)	{
+				if(fmtprec.length) fmtprec += String.fromCharCode(c);
+				else if(c == 48 && !fmtwidth.length) fmtflags += String.fromCharCode(c);
+				else fmtwidth += String.fromCharCode(c);
+		} else switch(c) {
+			/* positional */
+			case 36:
+				if(fmtprec.length) fmtprec += "$";
+				else if(fmtwidth.charAt(0) == "*") fmtwidth += "$";
+				else { fmtparam = fmtwidth + "$"; fmtwidth = ""; }
+				break;
+
+			/* flags */
+			case 39: fmtflags += "'"; break;
+			case 45: fmtflags += "-"; break;
+			case 43: fmtflags += "+"; break;
+			case 32: fmtflags += " "; break;
+			case 35: fmtflags += "#"; break;
+
+			/* width and precision */
+			case 46: fmtprec = "."; break;
+			case 42:
+				if(fmtprec.charAt(0) == ".") fmtprec += "*";
+				else fmtwidth += "*";
+				break;
+
+			/* length */
+			case 104:
+			case 108:
+				if(fmtlen.length > 1) throw "bad length " + fmtlen + String(c);
+				fmtlen += String.fromCharCode(c);
+				break;
+
+			case  76:
+			case 106:
+			case 122:
+			case 116:
+			case 113:
+			case  90:
+			case 119:
+				if(fmtlen !== "") throw "bad length " + fmtlen + String.fromCharCode(c);
+				fmtlen = String.fromCharCode(c);
+				break;
+
+			case 73:
+				if(fmtlen !== "") throw "bad length " + fmtlen + 'I';
+				fmtlen = 'I';
+				break;
+
+			/* conversion */
+			case 100:
+			case 105:
+			case 111:
+			case 117:
+			case 120:
+			case 88:
+			case 102:
+			case 70:
+			case 101:
+			case 69:
+			case 103:
+			case 71:
+			case 97:
+			case 65:
+			case 99:
+			case 67:
+			case 115:
+			case 83:
+			case 112:
+			case 110:
+			case 68:
+			case 85:
+			case 79:
+			case 109:
+			case 98:
+			case 66:
+			case 121:
+			case 89:
+			case 74:
+			case 86:
+			case 84:
+			case 37:
+				infmt = false;
+				if(fmtprec.length > 1) fmtprec = fmtprec.substr(1);
+				out.push([String.fromCharCode(c), fmt.substring(start, i+1), fmtparam, fmtflags, fmtwidth, fmtprec, fmtlen]);
+				start = i+1;
+				fmtlen = fmtprec = fmtwidth = fmtflags = fmtparam = "";
+				break;
+			default:
+				throw new Error("Invalid format string starting with |" + fmt.substring(start, i+1) + "|");
+		}
+
+	}
+
+	if(start < fmt.length) out.push(["L", fmt.substring(start)]);
+	return out;
+}
+
+//#define PAD_(x,c) (x >= 0 ? new Array(((x)|0) + 1).join((c)) : "")
+var padstr/*:{[s:string]:string}*/ = {
+	" ": "                                 ",
+	"0": "000000000000000000000000000000000",
+	"7": "777777777777777777777777777777777",
+	"f": "fffffffffffffffffffffffffffffffff"
+};
+
+var u_inspect/*:(o:any)=>string*/ = JSON.stringify;
+
+function doit(t/*:ParsedFmt*/, args/*:Array<any>*/)/*:string*/ {
+	var o/*:Array<string>*/ = [];
+	var argidx/*:number*/ = 0, idx/*:number*/ = 0;
+	var Vnum/*:number*/ = 0;
+	var pad/*:string*/ = "";
+	for(var i/*:number*/ = 0; i < t.length; ++i) {
+		var m/*:ParsedEntry*/ = t[i], c/*:number*/ = (m[0]/*:string*/).charCodeAt(0);
+		/* m order: conv full param flags width prec length */
+
+		if(c === /*L*/ 76) { o.push(m[1]); continue; }
+		if(c === /*%*/ 37) { o.push("%"); continue; }
+
+		var O/*:string*/ = "";
+		var isnum/*:number*/ = 0, radix/*:number*/ = 10, bytes/*:number*/ = 4, sign/*:boolean*/ = false;
+
+		/* flags */
+		var flags/*:string*/ = m[3]||"";
+		var alt/*:boolean*/ = flags.indexOf("#") > -1;
+
+		/* position */
+		if(m[2]) argidx = parseInt(m[2])-1;
+		/* %m special case */
+		else if(c === /*m*/ 109 && !alt) { o.push("Success"); continue; }
+
+		/* grab width */
+		var width =  0; if(m[ 4] != null && m[ 4].length > 0) { if(m[ 4].charAt(0) !== '*') width = parseInt(m[ 4], 10); else if(m[ 4].length === 1) width = args[idx++]; else width = args[parseInt(m[ 4].substr(1), 10)-1]; }
+
+		/* grab precision */
+		var prec =  -1; if(m[ 5] != null && m[ 5].length > 0) { if(m[ 5].charAt(0) !== '*') prec = parseInt(m[ 5], 10); else if(m[ 5].length === 1) prec = args[idx++]; else prec = args[parseInt(m[ 5].substr(1), 10)-1]; }
+
+		/* position not specified */
+		if(!m[2]) argidx = idx++;
+
+		/* grab argument */
+		var arg/*:any*/ = args[argidx];
+
+		/* grab length */
+		var len/*:string*/ = m[6] || "";
+
+		switch(c) {
+			/* str cCsS */
+
+			case /*S*/  83:
+			case /*s*/ 115:
+				/* only valid flag is "-" for left justification */
+				O = String(arg);
+				if( prec >= 0) O = O.substr(0,  prec);
+				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
+				break;
+
+			/* first char of string or convert */
+			case /*C*/  67:
+			case /*c*/  99:
+				switch(typeof arg) {
+					case "number":
+						var cc/*:number*/ = arg;
+						if(c == 67 || len.charCodeAt(0) === /*l*/ 108) {  cc &= 0xFFFFFFFF; O = String.fromCharCode( cc); }
+						else {  cc &= 0xFF; O = String.fromCharCode( cc); }
+						break;
+					case "string": O = /*::(*/arg/*:: :string)*/.charAt(0); break;
+					default: O = String(arg).charAt(0);
+				}
+				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
+				break;
+
+			/* int diDuUoOxXbB */
+
+			/* signed integer */
+			case /*D*/  68: bytes = 8;
+			/* falls through */
+			case /*d*/ 100:
+			case /*i*/ 105: isnum = -1; sign = true; break;
+
+			/* unsigned integer */
+			case /*U*/  85: bytes = 8;
+			/* falls through */
+			case /*u*/ 117: isnum = -1; break;
+
+			/* unsigned octal */
+			case /*O*/  79: bytes = 8;
+			/* falls through */
+			case /*o*/ 111: isnum = -1; radix = (8); break;
+
+			/* unsigned hex */
+			case /*x*/ 120: isnum = -1; radix = (-16); break;
+			case /*X*/  88: isnum = -1; radix = (16); break;
+
+			/* unsigned binary (extension) */
+			case /*B*/  66: bytes = 8;
+			/* falls through */
+			case /*b*/  98: isnum = -1; radix = (2); break;
+
+			/* flt fegFEGaA */
+
+			/* floating point logic */
+			case /*F*/  70:
+			case /*f*/ 102: isnum = (1); break;
+
+			case /*E*/  69:
+			case /*e*/ 101: isnum = (2); break;
+
+			case /*G*/  71:
+			case /*g*/ 103: isnum = (3); break;
+
+			/* floating hex */
+			case /*A*/  65:
+			case /*a*/  97: isnum = (4); break;
+
+			/* misc pnmJVTyY */
+
+			/* JS has no concept of pointers so interpret the `l` key as an address */
+			case /*p*/ 112:
+				Vnum = typeof arg == "number" ? arg : arg ? Number(arg.l) : -1;
+				if(isNaN(Vnum)) Vnum = -1;
+				if(alt) O = Vnum.toString(10);
+				else {
+					Vnum = Math.abs(Vnum);
+					O = "0x" + Vnum.toString(16).toLowerCase();
+				}
+				break;
+
+			/* store length in the `len` key */
+			case /*n*/ 110:
+				if(arg) { arg.len=0; for(var oo/*:number*/ = 0; oo < o.length; ++oo) arg.len += o[oo].length; }
+				continue;
+
+			/* process error */
+			case /*m*/ 109:
+				if(!(arg instanceof Error)) O = "Success";
+				else if(arg.message) O = arg.message;
+				else if(arg.errno) O = "Error number " + arg.errno;
+				else O = "Error " + String(arg);
+				break;
+
+			/* JS-specific conversions (extension) */
+			case /*J*/  74: O = (alt ? u_inspect : JSON.stringify)(arg); break;
+			case /*V*/  86: O = arg == null ? "null" : String(arg.valueOf()); break;
+			case /*T*/  84:
+				if(alt) { /* from '[object %s]' extract %s */
+					O = Object.prototype.toString.call(arg).substr(8);
+					O = O.substr(0, O.length - 1);
+				} else O = typeof arg;
+				break;
+
+			/* boolean (extension) */
+			case /*Y*/  89:
+			case /*y*/ 121:
+				O = (arg) ? (alt ? "yes" : "true") : (alt ? "no" : "false");
+				if(c == /*Y*/ 89) O = O.toUpperCase();
+				if( prec >= 0) O = O.substr(0,  prec);
+				if( width > O.length || - width > O.length) { if(( flags.indexOf("-") == -1 ||  width < 0) &&  flags.indexOf("0") != -1) { pad = ( width - O.length >= 0 ? padstr["0"].substr(0, width - O.length) : ""); O = pad + O; } else { pad = ( width - O.length >= 0 ? padstr[" "].substr(0, width - O.length) : ""); O =  flags.indexOf("-") > -1 ? O + pad : pad + O; } }
+				break;
+
+		}
+
+		if(width < 0) { width = -width; flags += "-"; }
+
+		if(isnum == -1) {
+
+			Vnum = Number(arg);
+
+			/* parse byte length field */
+
+			switch(len) {
+				/* char */
+				case "hh": { bytes = 1; } break;
+				/* short */
+				case "h":  { bytes = 2; } break;
+
+				/* long */
+				case "l":  { if(bytes == 4) bytes = 8; } break;
+
+				/* long long */
+				case "L":
+				case "q":
+				case "ll": { if(bytes == 4) bytes = 8; } break;
+
+				/* intmax_t */
+				case "j":  { if(bytes == 4) bytes = 8; } break;
+
+				/* ptrdiff_t */
+				case "t":  { if(bytes == 4) bytes = 8; } break;
+
+				/* size_t */
+				case "z":
+				case "Z":  { if(bytes == 4) bytes = 8; } break;
+
+				/* CRT size_t or ptrdiff_t */
+				case "I":
+
+					{ if(bytes == 4) bytes = 8; }
+
+					break;
+
+				/* CRT wchar_t */
+				case "w": break;
+			}
+
+			/* restrict value */
+
+			switch(bytes) {
+				case 1: Vnum = (Vnum & 0xFF); if(sign && (Vnum >  0x7F)) Vnum -= (0xFF + 1); break;
+				case 2: Vnum = (Vnum & 0xFFFF); if(sign && (Vnum >  0x7FFF)) Vnum -= (0xFFFF + 1); break;
+				case 4: Vnum = sign ? (Vnum | 0) : (Vnum >>> 0); break;
+				default: Vnum = isNaN(Vnum) ? 0 : Math.round(Vnum); break;
+			}
+
+			/* generate string */
+			if(bytes > 4 && Vnum < 0 && !sign) {
+				if(radix == 16 || radix == -16) {
+					O = (Vnum>>>0).toString(16);
+					Vnum = Math.floor((Vnum - (Vnum >>> 0)) / Math.pow(2,32));
+					O = (Vnum>>>0).toString(16) + (8 - O.length >= 0 ? padstr[ "0"].substr(0,8 - O.length) : "") + O;
+					O = (16 - O.length >= 0 ? padstr[ "f"].substr(0,16 - O.length) : "") + O;
+					if(radix == 16) O = O.toUpperCase();
+				} else if(radix == 8) {
+					O = (Vnum>>>0).toString(8);
+					O = (10 - O.length >= 0 ? padstr[ "0"].substr(0,10 - O.length) : "") + O;
+					Vnum = Math.floor((Vnum - ((Vnum >>> 0)&0x3FFFFFFF)) / Math.pow(2,30));
+					O = (Vnum>>>0).toString(8) + O.substr(O.length - 10);
+					O = O.substr(O.length - 20);
+					O = "1" + (21 - O.length >= 0 ? padstr[ "7"].substr(0,21 - O.length) : "") + O;
+				} else {
+					Vnum = (-Vnum) % 1e16;
+					var d1/*:Array<number>*/ = [1,8,4,4,6,7,4,4,0,7,3,7,0,9,5,5,1,6,1,6];
+					var di/*:number*/ = d1.length - 1;
+					while(Vnum > 0) {
+						if((d1[di] -= (Vnum % 10)) < 0) { d1[di] += 10; d1[di-1]--; }
+						--di; Vnum = Math.floor(Vnum / 10);
+					}
+					O = d1.join("");
+				}
+			} else {
+				if(radix === -16) O = Vnum.toString(16).toLowerCase();
+				else if(radix === 16) O = Vnum.toString(16).toUpperCase();
+				else O = Vnum.toString(radix);
+			}
+
+			/* apply precision */
+			if(prec ===0 && O == "0" && !(radix == 8 && alt)) O = ""; /* bail out */
+			else {
+				if(O.length < prec + (O.substr(0,1) == "-" ? 1 : 0)) {
+					if(O.substr(0,1) != "-") O = (prec - O.length >= 0 ? padstr[ "0"].substr(0,prec - O.length) : "") + O;
+					else O = O.substr(0,1) + (prec + 1 - O.length >= 0 ? padstr[ "0"].substr(0,prec + 1 - O.length) : "") + O.substr(1);
+				}
+
+				/* add prefix for # form */
+				if(!sign && alt && Vnum !== 0) switch(radix) {
+					case -16: O = "0x" + O; break;
+					case  16: O = "0X" + O; break;
+					case   8: if(O.charAt(0) != "0") O =  "0" + O; break;
+					case   2: O = "0b" + O; break;
+				}
+			}
+
+			/* add sign character */
+			if(sign && O.charAt(0) != "-") {
+				if(flags.indexOf("+") > -1) O = "+" + O;
+				else if(flags.indexOf(" ") > -1) O = " " + O;
+			}
+			/* width */
+			if(width > 0) {
+				if(O.length < width) {
+					if(flags.indexOf("-") > -1) {
+						O = O + ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "");
+					} else if(flags.indexOf("0") > -1 && prec < 0 && O.length > 0) {
+						if(prec > O.length) O = ((prec - O.length) >= 0 ? padstr[ "0"].substr(0,(prec - O.length)) : "") + O;
+						pad = ((width - O.length) >= 0 ? padstr[ (prec > 0 ? " " : "0")].substr(0,(width - O.length)) : "");
+						if(O.charCodeAt(0) < 48) {
+							if(O.charAt(2).toLowerCase() == "x") O = O.substr(0,3) + pad + O.substring(3);
+							else O = O.substr(0,1) + pad + O.substring(1);
+						}
+						else if(O.charAt(1).toLowerCase() == "x") O = O.substr(0,2) + pad + O.substring(2);
+						else O = pad + O;
+					} else {
+						O = ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "") + O;
+					}
+				}
+			}
+
+		} else if(isnum > 0) {
+
+			Vnum = Number(arg);
+			if(arg === null) Vnum = 0/0;
+			if(len == "L") bytes = 12;
+			var isf/*:boolean*/ = isFinite(Vnum);
+			if(!isf) { /* Infinity or NaN */
+				if(Vnum < 0) O = "-";
+				else if(flags.indexOf("+") > -1) O = "+";
+				else if(flags.indexOf(" ") > -1) O = " ";
+				O += (isNaN(Vnum)) ? "nan" : "inf";
+			} else {
+				var E/*:number*/ = 0;
+
+				if(prec == -1 && isnum != 4) prec = 6;
+
+				/* g/G conditional behavior */
+				if(isnum == 3) {
+					O = Vnum.toExponential(1);
+					E = +O.substr(O.indexOf("e") + 1);
+					if(prec === 0) prec = 1;
+					if(prec > E && E >= -4) { isnum = (11); prec = prec -(E + 1); }
+					else { isnum = (12); prec = prec - 1; }
+				}
+
+				/* sign: workaround for negative zero */
+				var sg/*:string*/ = (Vnum < 0 || 1/Vnum == -Infinity) ? "-" : "";
+				if(Vnum < 0) Vnum = -Vnum;
+
+				switch(isnum) {
+					/* f/F standard */
+					case 1: case 11:
+						if(Vnum < 1e21) {
+							O = Vnum.toFixed(prec);
+							if(isnum == 1) { if(prec===0 &&alt&& O.indexOf(".")==-1) O+="."; }
+							else if(!alt) O=O.replace(/(\.\d*[1-9])0*$/,"$1").replace(/\.0*$/,"");
+							else if(O.indexOf(".") == -1) O+= ".";
+							break;
+						}
+						O = Vnum.toExponential(20);
+						E = +O.substr(O.indexOf("e")+1);
+						O = O.charAt(0) + O.substr(2,O.indexOf("e")-2);
+						O = O + (E - O.length + 1 >= 0 ? padstr[ "0"].substr(0,E - O.length + 1) : "");
+						if(alt || (prec > 0 && isnum !== 11)) O = O + "." + (prec >= 0 ? padstr[ "0"].substr(0,prec) : "");
+						break;
+
+					/* e/E exponential */
+					case 2: case 12:
+						O = Vnum.toExponential(prec);
+						E = O.indexOf("e");
+						if(O.length - E === 3) O = O.substr(0, E+2) + "0" + O.substr(E+2);
+						if(alt && O.indexOf(".") == -1) O = O.substr(0,E) +"."+ O.substr(E);
+						else if(!alt && isnum == 12) O = O.replace(/\.0*e/, "e").replace(/\.(\d*[1-9])0*e/, ".$1e");
+						break;
+
+					/* a/A hex */
+					case 4:
+						if(Vnum===0){O= "0x0"+((alt||prec>0)?"."+(prec >= 0 ? padstr["0"].substr(0,prec) : ""):"")+"p+0"; break;}
+						O = Vnum.toString(16);
+						/* First char 0-9 */
+						var ac/*:number*/ = O.charCodeAt(0);
+						if(ac == 48) {
+							ac = 2; E = -4; Vnum *= 16;
+							while(O.charCodeAt(ac++) == 48) { E -= 4; Vnum *= 16; }
+							O = Vnum.toString(16);
+							ac = O.charCodeAt(0);
+						}
+
+						var ai/*:number*/ = O.indexOf(".");
+						if(O.indexOf("(") > -1) {
+							/* IE exponential form */
+							var am/*:?Array<any>*/ = O.match(/\(e(.*)\)/);
+							var ae/*:number*/ = am ? (+am[1]) : 0;
+							E += 4 * ae; Vnum /= Math.pow(16, ae);
+						} else if(ai > 1) {
+							E += 4 * (ai - 1); Vnum /= Math.pow(16, ai - 1);
+						} else if(ai == -1) {
+							E += 4 * (O.length - 1); Vnum /= Math.pow(16, O.length - 1);
+						}
+
+						/* at this point 1 <= Vnum < 16 */
+
+						if(bytes > 8) {
+							if(ac < 50) { E -= 3; Vnum *= 8; }
+							else if(ac < 52) { E -= 2; Vnum *= 4; }
+							else if(ac < 56) { E -= 1; Vnum *= 2; }
+							/* at this point 8 <= Vnum < 16 */
+						} else {
+							if(ac >= 56) { E += 3; Vnum /= 8; }
+							else if(ac >= 52) { E += 2; Vnum /= 4; }
+							else if(ac >= 50) { E += 1; Vnum /= 2; }
+							/* at this point 1 <= Vnum < 2 */
+						}
+
+						O = Vnum.toString(16);
+						if(O.length > 1) {
+							if(O.length > prec+2 && O.charCodeAt(prec+2) >= 56) {
+								var _f/*:boolean*/ = O.charCodeAt(0) == 102;
+								O = (Vnum + 8 * Math.pow(16, -prec-1)).toString(16);
+								if(_f && O.charCodeAt(0) == 49) E += 4;
+							}
+							if(prec > 0) {
+								O = O.substr(0, prec + 2);
+								if(O.length < prec + 2) {
+									if(O.charCodeAt(0) < 48) O = O.charAt(0) + ((prec + 2 - O.length) >= 0 ? padstr[ "0"].substr(0,(prec + 2 - O.length)) : "") + O.substr(1);
+									else O += ((prec + 2 - O.length) >= 0 ? padstr[ "0"].substr(0,(prec + 2 - O.length)) : "");
+								}
+							} else if(prec === 0) O = O.charAt(0) + (alt ? "." : "");
+						} else if(prec > 0) O = O + "." + (prec >= 0 ? padstr["0"].substr(0,prec) : "");
+						else if(alt) O = O + ".";
+						O = "0x" + O + "p" + (E>=0 ? "+" + E : E);
+						break;
+				}
+
+				if(sg === "") {
+					if(flags.indexOf("+") > -1) sg = "+";
+					else if(flags.indexOf(" ") > -1) sg = " ";
+				}
+
+				O = sg + O;
+			}
+
+			/* width */
+			if(width > O.length) {
+				if(flags.indexOf("-") > -1) {
+					O = O + ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "");
+				} else if(flags.indexOf("0") > -1 && O.length > 0 && isf) {
+					pad = ((width - O.length) >= 0 ? padstr[ "0"].substr(0,(width - O.length)) : "");
+					if(O.charCodeAt(0) < 48) {
+						if(O.charAt(2).toLowerCase() == "x") O = O.substr(0,3) + pad + O.substring(3);
+						else O = O.substr(0,1) + pad + O.substring(1);
+					}
+					else if(O.charAt(1).toLowerCase() == "x") O = O.substr(0,2) + pad + O.substring(2);
+					else O = pad + O;
+				} else {
+					O = ((width - O.length) >= 0 ? padstr[ " "].substr(0,(width - O.length)) : "") + O;
+				}
+			}
+			if(c < 96) O = O.toUpperCase();
+
+		}
+
+		o.push(O);
+	}
+	return o.join("");
+}
+
+function vsprintf(fmt/*:string*/, args/*:Args*/)/*:string*/ { return doit(tokenize(fmt), args); }
+
+function sprintf(/*:: ...argz*/)/*:string*/ {
+	var args/*:Array<any>*/ = new Array(arguments.length - 1);
+	for(var i/*:number*/ = 0; i < args.length; ++i) args[i] = arguments[i+1];
+	return doit(tokenize(arguments[0]), args);
+}
+
+export { sprintf, vsprintf };
+
--- a/tests/mjs.html
+++ b/tests/mjs.html
@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<!-- printj.js (C) 2016-present SheetJS http://sheetjs.com -->
+<!-- vim: set ts=2: -->
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+<title>PRINTJ Live Demo</title>
+<style>
+table, td {
+	border: 1px dotted black;
+	text-align: left;
+}
+</style>
+</head>
+<body>
+<b>PRINTJ ESM Live Demo</b><br />
+<a href="https://git.io/printj">Source Code Repo</a><br />
+<a href="https://git.io/printj_issues">Issues?  Something look weird?  Click here and report an issue</a><br />
+<br />
+<pre>
+usage: import { sprintf as printf } from './printj.mjs';
+
+This implementation supports the full POSIX set of conversions.  Consult the enclosed README for full details.
+</pre>
+<div><a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/printf.html">POSIX documentation</a></div><br />
+<table id="data">
+<tr><th>example</th><th>result</th></tr>
+</table>
+<script type="module">
+/* eslint-env browser */
+/*global PRINTJ */
+import { sprintf as printf } from './printj.mjs';
+var table = document.getElementById("data");
+var ex = [
+	'printf("|Hello %s|", "SheetJS")',
+	'printf("|%1$d %1$o %1$u %1$x %1$X|", 1234)',
+	'printf("|%1$d %1$o %1$u %1$x %1$X|", -1234)',
+	'printf("|%1$d %1$o %1$u %1$x %1$X %1$lld|", 2813308004)',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", 1.2)',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", Math.PI)',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", Math.LOG2E)',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", -Math.LOG10E)',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", Infinity)',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", -0)',
+	'printf("|%012s|", "SheetJS")',
+	'printf("|%-12s|", "SheetJS")',
+	'printf("|%1$f %1$F %1$e %1$E %1$g %1$G %1$a %1$A|", 1.4142E69)',
+	'printf("%%")'
+];
+window.onload = function() {
+	printf("Hello %s", "world");
+	ex.forEach(function(m) {
+		var row = table.insertRow(table.rows.length);
+		var c1 = row.insertCell(0); c1.innerHTML = "<pre>" + m + "</pre>";
+		var c2 = row.insertCell(1); c2.innerHTML = "<pre>" + eval(m) + "</pre>";
+	});
+};
+	var _gaq = _gaq || [];
+	_gaq.push(['_setAccount', 'UA-36810333-1']);
+	_gaq.push(['_trackPageview']);
+
+	(function() {
+		var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
+		ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
+		var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
+	})();
+</script>
+</body>
+</html>
+
--- a/tests/node.mjs
+++ b/tests/node.mjs
@ -0,0 +1,5 @@
+#!/usr/bin/env node --experimental-modules
+
+import { version, sprintf } from '../printj.mjs'
+
+console.log(sprintf("PRINTJ version %s, 123 = 0x%02hhx", version, 123));
--- a/tests/printj.mjs
+++ b/tests/printj.mjs
@ -0,0 +1 @@
+../printj.mjs