Regular Expression in countColumn method

suino · February 1, 2020, 5:24pm

CountColumn() method is mainly used to count number of text for indentation.
Then indentation is only created by half-width space or tab.
But regular expression in countColumn() method also counts spaces other than half-width space or tab.

github.com

codemirror/CodeMirror/blob/master/src/util/misc.js#L18


  for (let prop in obj)
    if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
      target[prop] = obj[prop]
  return target
}


// Counts the column offset in a string, taking tabs into account.
// Used mostly to find indentation.
export function countColumn(string, end, tabSize, startIndex, startValue) {
  if (end == null) {
    end = string.search(/[^\s\u00a0]/)
    if (end == -1) end = string.length
  }
  for (let i = startIndex || 0, n = startValue || 0;;) {
    let nextTab = string.indexOf("\t", i)
    if (nextTab < 0 || nextTab >= end)
      return n + (end - i)
    n += nextTab - i
    n += tabSize - (n % tabSize)
    i = nextTab + 1
  }

In my case:

I want to write \u3000（full-width space） on head of all lines when writing Japanese text.
\u3000 is included in \s.
For the reason, CodeMirror indents next line for half-width space.
However that I need is No-indent or Full-width space indent.

I suppose that appropriate regular expression is /[^\u0020\u00a0\t]/…

Is there any other way?

Thank you.

marijn · February 1, 2020, 8:48pm

CodeMirror’s indentation system is written with only (Latin) spaces and tabs in mind. I suspect adjusting it to do something sensible with Japanese spacing would require a lot more than just adjusting this regexp. So I’d advise you to avoid using the built-in indentation handling and write your own command to bind to Enter.

suino · February 9, 2020, 2:58pm

Thanks for your reply.
Following your advice, I built my own indentation handling and bind it to Enter. It’s just ok.
Although I had a little difficulty writing because most methods were private.

I have another idea.
When user uses prev mode, indentation should be calculated like belows:
if (pos < indentation) indentString += getLine(doc, n-1).text.match(/^\s*/)[0]
Because spaces is got like belows:
var curSpaceString = line.text.match(/^\s*/)[0], indentation;
I think these sentense should use same regexp.

Sorry for ranting.
I understand what you mean.
I’m glad if you consider not-Latin languages someday!

Thanks.