Width-insensitive regex matching

Question

I know how to make a regex case-insensitive. This is not about case but about character width. I'm looking for something that is width-insensitive. In Japanese, you have half-width and full-width characters (consider ０１２３ vs 0123 or ABCD vs ＡＢＣＤ). You can make SQL Server databases width-insensitive with _WI (or width-sensitive with _WS). I was hoping there would be something similar for a regex.

I'm trying to find birth dates where the numbers can be half and full width. Here's an illustration of the problem

For a more specific date matching problem, here's another illustration:

So while \d{4} finds instances of 4 digits, it will not find 4 full-width digits, etc. The workaround I've found is to do something like [０１２３４５６７８９|\d]{4} like so:

But that feels really dirty. Is there a better way to do this?

Answer 1

To match ASCII or full-width digits you can use

[０-９\d]

Or, [\uFF10-\uFF19\d] if you need to abstract from using Unicode text in your source.

Note that in ECMAScript 2018 and later, you can use \p{N} or \p{Nd} to match all Unicode digits.

The current \p{N} range (encompassing Number, Decimal Digit (Nd), Number, Letter (Nl) and Number, Other (No) categories) regex matching 1,791 code points is

(?:[0-9\xB2\xB3\xB9\xBC-\xBE\u0660-\u0669\u06F0-\u06F9\u07C0-\u07C9\u0966-\u096F\u09E6-\u09EF\u09F4-\u09F9\u0A66-\u0A6F\u0AE6-\u0AEF\u0B66-\u0B6F\u0B72-\u0B77\u0BE6-\u0BF2\u0C66-\u0C6F\u0C78-\u0C7E\u0CE6-\u0CEF\u0D58-\u0D5E\u0D66-\u0D78\u0DE6-\u0DEF\u0E50-\u0E59\u0ED0-\u0ED9\u0F20-\u0F33\u1040-\u1049\u1090-\u1099\u1369-\u137C\u16EE-\u16F0\u17E0-\u17E9\u17F0-\u17F9\u1810-\u1819\u1946-\u194F\u19D0-\u19DA\u1A80-\u1A89\u1A90-\u1A99\u1B50-\u1B59\u1BB0-\u1BB9\u1C40-\u1C49\u1C50-\u1C59\u2070\u2074-\u2079\u2080-\u2089\u2150-\u2182\u2185-\u2189\u2460-\u249B\u24EA-\u24FF\u2776-\u2793\u2CFD\u3007\u3021-\u3029\u3038-\u303A\u3192-\u3195\u3220-\u3229\u3248-\u324F\u3251-\u325F\u3280-\u3289\u32B1-\u32BF\uA620-\uA629\uA6E6-\uA6EF\uA830-\uA835\uA8D0-\uA8D9\uA900-\uA909\uA9D0-\uA9D9\uA9F0-\uA9F9\uAA50-\uAA59\uABF0-\uABF9\uFF10-\uFF19]|\uD800[\uDD07-\uDD33\uDD40-\uDD78\uDD8A\uDD8B\uDEE1-\uDEFB\uDF20-\uDF23\uDF41\uDF4A\uDFD1-\uDFD5]|\uD801[\uDCA0-\uDCA9]|\uD802[\uDC58-\uDC5F\uDC79-\uDC7F\uDCA7-\uDCAF\uDCFB-\uDCFF\uDD16-\uDD1B\uDDBC\uDDBD\uDDC0-\uDDCF\uDDD2-\uDDFF\uDE40-\uDE48\uDE7D\uDE7E\uDE9D-\uDE9F\uDEEB-\uDEEF\uDF58-\uDF5F\uDF78-\uDF7F\uDFA9-\uDFAF]|\uD803[\uDCFA-\uDCFF\uDD30-\uDD39\uDE60-\uDE7E\uDF1D-\uDF26\uDF51-\uDF54\uDFC5-\uDFCB]|\uD804[\uDC52-\uDC6F\uDCF0-\uDCF9\uDD36-\uDD3F\uDDD0-\uDDD9\uDDE1-\uDDF4\uDEF0-\uDEF9]|\uD805[\uDC50-\uDC59\uDCD0-\uDCD9\uDE50-\uDE59\uDEC0-\uDEC9\uDF30-\uDF3B]|\uD806[\uDCE0-\uDCF2\uDD50-\uDD59]|\uD807[\uDC50-\uDC6C\uDD50-\uDD59\uDDA0-\uDDA9\uDFC0-\uDFD4]|\uD809[\uDC00-\uDC6E]|\uD81A[\uDE60-\uDE69\uDEC0-\uDEC9\uDF50-\uDF59\uDF5B-\uDF61]|\uD81B[\uDE80-\uDE96]|\uD834[\uDEE0-\uDEF3\uDF60-\uDF78]|\uD835[\uDFCE-\uDFFF]|\uD838[\uDD40-\uDD49\uDEF0-\uDEF9]|\uD83A[\uDCC7-\uDCCF\uDD50-\uDD59]|\uD83B[\uDC71-\uDCAB\uDCAD-\uDCAF\uDCB1-\uDCB4\uDD01-\uDD2D\uDD2F-\uDD3D]|\uD83C[\uDD00-\uDD0C]|\uD83E[\uDFF0-\uDFF9])

and the \p{Nd} (with 660 code points) converts to

(?:[0-9\u0660-\u0669\u06F0-\u06F9\u07C0-\u07C9\u0966-\u096F\u09E6-\u09EF\u0A66-\u0A6F\u0AE6-\u0AEF\u0B66-\u0B6F\u0BE6-\u0BEF\u0C66-\u0C6F\u0CE6-\u0CEF\u0D66-\u0D6F\u0DE6-\u0DEF\u0E50-\u0E59\u0ED0-\u0ED9\u0F20-\u0F29\u1040-\u1049\u1090-\u1099\u17E0-\u17E9\u1810-\u1819\u1946-\u194F\u19D0-\u19D9\u1A80-\u1A89\u1A90-\u1A99\u1B50-\u1B59\u1BB0-\u1BB9\u1C40-\u1C49\u1C50-\u1C59\uA620-\uA629\uA8D0-\uA8D9\uA900-\uA909\uA9D0-\uA9D9\uA9F0-\uA9F9\uAA50-\uAA59\uABF0-\uABF9\uFF10-\uFF19]|\uD801[\uDCA0-\uDCA9]|\uD803[\uDD30-\uDD39]|\uD804[\uDC66-\uDC6F\uDCF0-\uDCF9\uDD36-\uDD3F\uDDD0-\uDDD9\uDEF0-\uDEF9]|\uD805[\uDC50-\uDC59\uDCD0-\uDCD9\uDE50-\uDE59\uDEC0-\uDEC9\uDF30-\uDF39]|\uD806[\uDCE0-\uDCE9\uDD50-\uDD59]|\uD807[\uDC50-\uDC59\uDD50-\uDD59\uDDA0-\uDDA9]|\uD81A[\uDE60-\uDE69\uDEC0-\uDEC9\uDF50-\uDF59]|\uD835[\uDFCE-\uDFFF]|\uD838[\uDD40-\uDD49\uDEF0-\uDEF9]|\uD83A[\uDD50-\uDD59]|\uD83E[\uDFF0-\uDFF9])