FR: Ability to retain whitespace in AST

[gadicc]

Hi there, I'm the author of meteor-messageformat which is using intl-messageformat in it's next iteration. Some of our users would like the ability to retain whitespace in the final translated string, which, for example, might then be parsed later by markdown.

Would this be possible? I'm assuming this isn't a feature that will be desired most of the time, therefore I'm guessing the biggest job would be to allow intl-messageformat to accept options that could be parsed down to the parser. What are your thoughts?

[caridy]

I don't think ICU cares about the spaces in the message, maybe @SlexAxton or @ericf will know better. Our current parser (written by @ericf) might be doing some trimming. PR #8 is suppose to revamp the parser, but we haven't get a chance to get to that.

[SlexAxton]

ICU cares about the spaces in the output-text portion of the full message, but not in the control statements. (I don't have proof/spec-quotation, but that's been my observation)

On Wed, Jul 8, 2015, 12:01 PM Caridy Patiño notifications@github.com wrote:

I don't think ICU cares about the spaces in the message, maybe @SlexAxton https://github.com/SlexAxton or @ericf https://github.com/ericf will know better. Our current parser (written by @ericf https://github.com/ericf) might be doing some trimming. PR #8 https://github.com/yahoo/intl-messageformat-parser/pull/8 is suppose to revamp the parser, but we haven't get a chance to get to that.

— Reply to this email directly or view it on GitHub https://github.com/yahoo/intl-messageformat-parser/issues/10#issuecomment-119662689 .

[ericf]

ICU cares about the spaces in the output-text portion of the full message, but not in the control statements. (I don't have proof/spec-quotation, but that's been my observation)

I remember reading this somewhere as well — which is why it's ignored. There's no whitespace data in the current AST format, but maybe you could write a pretty printer which follows some default formatting rules, like this for plurals:

You have {numMessages, plural,
  one {# message}
  other {# messages}
} in your inbox.

[ericf]

Here's a basic AST --> ICU Message string printer I happened to write yesterday if you'd like it as a starting point:

export default function printICUMessage(ast) {
    return ast.elements.reduce((message, el) => {
        let {format, id, type, value} = el;

        if (type === 'messageTextElement') {
            return message + value;
        }

        if (!format) {
            return message + `{${id}}`;
        }

        let formatType = format.type.replace(/Format$/, '');

        switch (formatType) {
            case 'number':
            case 'date':
            case 'time':
                let style = format.style ? `, ${format.style}` : '';
                return message + `{${id}, ${formatType}${style}}`;

            case 'plural':
            case 'selectOrdinal':
            case 'select':
                let offset = format.offset ? `, offset:${format.offset}` : '';
                let options = format.options.reduce((str, option) => {
                    let optionValue = printICUMessage(option.value);
                    return str + ` ${option.selector} {${optionValue}}`;
                }, '');
                return message + `{${id}, ${formatType}${offset},${options}}`;
        }
    }, '');
}