@Bravilogy I use them for a permissions system in my api. When I do it in JS I use a library I wrote: https://www.npmjs.com/package/flagon to make it seem less arcane.
In postgres, I use operators like bit_or.
You can do cool stuff like:
var auth_permissions_read = group_permissions.reduce( flagon.merge, 0)And in sql:
coalesce(
bit_or(
case when GE.group_permissions_read
then P.permission_flag else 0
end
)
,0
) as auth_permissions_readI prefer not to use | / & directly, because its not immediately obvious to other people on the team that they aren't meant to be || or &&.
And in some cases, its super hard to read e.g. flagon.contains equates to: B == 0 || ((A & B) == B)
It'd be fun to implement bit flag operations as monoids. Then you could have
merge be OR.concat and toggle could be XOR.concatetc
Maybe something like this?
const OR = {
of: a => ({
fold: () => a
,toString: () => [
'OR(0b',a.toString(2),')'
].join('')
,concat: b => OR.of(b.fold() | a)
})
,concat: (a,b) => a.concat(b)
,empty: () => OR.of(0)
}
var f = pipe(
map(OR.of)
,reduce(OR.concat, OR.empty())
)
f([0b001, 0b010, 0b100])
//=> 0b111
@JAForbes I'm pretty sure someone posted to this gitter a link to a functional bitwise operators library they wrote, but my google fu is failing me at the moment.
Been fooling around with this today: https://goo.gl/9Uiw3E @kurtmilam
Hey can someone show a usage of Alt? Its behaviour seems wide open from the spec. What's a common usage?
:thumbsup:
Wow, I've just realized that on documentation there is tiny text "expand parameters", which describe parameters. I am using Ramda for ~3 months :smile:
Hey, I need tip how can I replace placeholders in string
I've did https://goo.gl/qYopHt
Any ideas how to improve it?
I've did https://goo.gl/qYopHt
Any ideas how to improve it?
Hey, thx, however think its not suitable here
I need to allow to set custom placeholder
I need to allow to set custom placeholder
{{{ }}} and text is stored as plan text
@mimol91 https://developers.google.com/web/updates/2015/01/ES6-Template-Strings
you can do it like "format
you can do it like "format
some string with placeholders"
Not sure if I catch what you mean.
@mimol91 maybe using regex to replace the placeholder. rather than iterate the object keys like that.
R.replace is using regexp internally. What do you mean by that?
@mimol91
const text = `
Demo variable = {{{demo}}}
Foo = {{{foo}}}
`;
const vars = {
demo: 'I m demo!',
foo: 'fooVar'
};
text.replace(/{{{(\w+)}}}/g, function (match, key) {
return vars[key];
});
//=> "\n Demo variable = I m demo! \n Foo = fooVar\n”The replace() method returns a new string with some or all matches of a pattern replaced by a replacement.
i mean like this: https://goo.gl/cIvt0b. your implementation create intermediate string as much as keys on the object
@miwillhite thanks
@miwillhite it took me some time thinking it through but I managed to finish it points-free:
const ary2 = R.pipe(R.nAry(2), R.curry);
const testPermissionsPath = testPath(['settings', 'permissions']);
const testPermissionsAnd = R.useWith(R.both, [R.identity, testPermissionsPath]);
const filterRouteBy = ary2(R.pipe(testPermissionsAnd, R.filter));
const filterByPermissionsTestAnd = R.pipe(filterRouteBy, R.uncurryN(2));
used as:
(isNavBarRoute) => (hasSomePermissions) => (routes) => (filteredRoutes) =D
oh
useWith, that is what I needed yesterday! ;)
My current understanding of Alt is that it's much like Semigroup, except that you're not allowed to look at the inner values, only the types. It's a "higher-level" form of taking two things and getting one thing from it. But because you can't look at the inner values you can't do this by combining, you can only do it by choosing.
So one logic for M.alt(M) with a Maybe would be "take the first M unless it's a Nothing, in which case take the second" or "first Just always wins"
One I've heard described for sequential Tasks would be "run the first M and if it succeeds, return it, but if it fails, then and only then run the second Task and return it" (whereas parallel Tasks would run both and take the one that finished first, or the first one in a "tie" though in practice I don't think a "tie" is possible)
would pick work on buffers?
pick([1,3,5], Buffer("af3de4d60935f3", "hex")) === Buffer("3dd635", "hex")