def OptState.join

bendtorch@1.3.0.0 · main.bend:89

import Base

89# Pair the buffers present on both sides. Internal callers split one state, then step both children with the same
90# optimizer, so the variants agree. No buffer is ever allocated to fill an absent side.
91def OptState.join(-A: Type, -B: Type, a: OptState<A>, b: OptState<B>) -> OptState<Two<A, B>>:
92  match a b:
93    case OneMom{x} OneMom{y}: OneMom{Two{x, y}}
94    case TwoMom{x, u} TwoMom{y, v}: TwoMom{Two{x, y}, Two{u, v}}
95    case Packed{x} Packed{y}: Packed{PNode{x, y}}
96    case _ _: NoMom{}