BarAssembly

Infix notation for hand-building explicit persistence bars: lower upper constructs a BarAssembly, which dim(d)(...) then turns into a PersistenceBar. Each infix method's name spells out its endpoint kinds in birth-then-death order: cl = closed, op = open, inf = infinite (only ever at the far end -- negative infinity as a lower bound, positive infinity as an upper bound). So a clop b is the closed-open bar [a, b) (the usual half-open persistence interval, and what the bare bc alias also means); a clcl b is [a, b]; a opop b is (a, b); a opcl b is (a, b]; clinf(a)/opinf(a) are [a, ∞)/(a, ∞); infcl(b)/infop(b) are (-∞, b]/(-∞, b).

val ctx = BarcodeContext[Double]()
import ctx.*
ctx.dim(1)(3.0 clop 5.0)   // PersistenceBar(1, ClosedEndpoint(3.0), OpenEndpoint(5.0))
ctx.dim(0)(clinf(2.0))     // PersistenceBar(0, ClosedEndpoint(2.0), PositiveInfinity())