import type { IObjectOf } from "@thi.ng/api" ; /**
 * Higher order helper function for  rename transducer. Takes an object
 * of key mappings and returns function applying these mapping/renames.
 *
 *  param kmap export const renamer = ( kmap ) => { const ks = Object . keys ( kmap ) ; const [ a2 , b2 , c2 ] = ks ; const [ a1 , b1 , c1 ] = ks . map ( ( k ) => kmap [ k ] ) ; switch ( ks . length ) { case 3 : return ( x ) => { const res = { } ; let v ; ( v = x [ c1 ] ) , v !== undefined && ( res [ c2 ] = v ) ; ( v = x [ b1 ] ) , v !== undefined && ( res [ b2 ] = v ) ; ( v = x [ a1 ] ) , v !== undefined && ( res [ a2 ] = v ) ; return res ; } ; case 2 : return ( x ) => { const res = { } ; let v ; ( v = x [ b1 ] ) , v !== undefined && ( res [ b2 ] = v ) ; ( v = x [ a1 ] ) , v !== undefined && ( res [ a2 ] = v ) ; return res ; } ; case 1 : return ( x ) => { const res = { } ; let v = x [ a1 ] ; v !== undefined && ( res [ a2 ] = v ) ; return res ; } ; default : return ( x ) => { let k , v ; const res = { } ; for ( let i = ks . length - 1 ; i >= 0 ; i -- ) { ( k = ks [ i ] ) , ( v = x [ kmap [ k ] ] ) , v !== undefined && ( res [ k ] = v ) ; } return res ; } ; } } ;