Function ifTopExpr

docs/app/js/sanddance-app.js:148834–148834

($orient, a, b)

const ifYEnc = ($orient, a, b)=>ifEnc(`${$orient} !== '${Top}' && ${$orient} !== '${Bottom}'`, a, b);
const ifLeftTopExpr = ($orient, a, b)=>ifExpr(`${$orient} === '${Left}' || ${$orient} === '${Top}'`, a, b);
const ifTopExpr = ($orient, a, b)=>ifExpr(`${$orient} === '${Top}'`, a, b);
const ifRightExpr = ($orient, a, b)=>ifExpr(`${$orient} === '${Right}'`, a, b);
const ifEnc = (test, a, b)=>{
    // ensure inputs are encoder objects (or null)