groupBy'
lib.lists.groupBy' (Prime)
Docs pulled from | This Revision | 35 minutes ago
Splits the elements of a list into many lists, using the return value of a predicate.
Predicate should return a string which becomes keys of attrset groupBy returns.
groupBy' allows to customise the combining function and initial value
Inputs
op-
1. Function argument
nul-
2. Function argument
pred-
3. Function argument
lst-
4. Function argument
Examples
lib.lists.groupBy' usage example
groupBy (x: boolToString (x > 2)) [ 5 1 2 3 4 ]
=> { true = [ 5 3 4 ]; false = [ 1 2 ]; }
groupBy (x: x.name) [ {name = "icewm"; script = "icewm &";}
{name = "xfce"; script = "xfce4-session &";}
{name = "icewm"; script = "icewmbg &";}
{name = "mate"; script = "gnome-session &";}
]
=> { icewm = [ { name = "icewm"; script = "icewm &"; }
{ name = "icewm"; script = "icewmbg &"; } ];
mate = [ { name = "mate"; script = "gnome-session &"; } ];
xfce = [ { name = "xfce"; script = "xfce4-session &"; } ];
}
groupBy' builtins.add 0 (x: boolToString (x > 2)) [ 5 1 2 3 4 ]
=> { true = 12; false = 3; }