Branch Fold Forward

Gallery / Serpentine Layout

A side branch (Aux) shares a topo column with the spine (Genome). At a low fold threshold the serpentine packer skips that branch column as a fold point - folding it would strand Genome's consumer (Post) behind it - and folds the spine instead, so every inter-section edge flows forward and Genome's exit faces Post (issue #1080).

Mermaid source

%%metro title: Branch fold stays forward
%%metro fold_threshold: 6
%%metro line: main | Main | #0570b0
%%metro line: side | Side | #e63946

graph LR
    subgraph intake [Intake]
        i0[ ]
        i1[Trim]
        i2[Filter]
        i3[QC]
        i0 -->|main,side| i1
        i1 -->|main,side| i2
        i2 -->|main,side| i3
    end
    subgraph genome [Genome]
        %%metro entry: left | main
        %%metro exit: right | main
        g0[Align]
        g1[Dedup]
        g2[Quant]
        g0 -->|main| g1
        g1 -->|main| g2
    end
    subgraph aux [Aux]
        %%metro entry: left | side
        a0[Pseudo]
        a1[Count]
        a0 -->|side| a1
    end
    subgraph post [Post]
        %%metro entry: left | main
        %%metro exit: bottom | main
        p0[Mark]
        p1[Track]
        p0 -->|main| p1
    end
    subgraph report [Report]
        %%metro direction: RL
        %%metro entry: top | main
        r0[Collect]
        r1[ ]
        r0 -->|main| r1
    end
    i3 -->|main| g0
    i3 -->|side| a0
    g2 -->|main| p0
    p1 -->|main| r0

CLI command

nf-metro render examples/topologies/branch_fold_forward.mmd -o branch_fold_forward.svg

Rendered map