Block Diagram (WIP)

Syntax suggestion for layout (paperware)

Simple block

block
  columns 1
  block1[Block 1]

Blocks next to each other

block
  columns 2
  block1[Block 1]
  block2[Block 2]

Blocks in a column

block
  columns 1
  block1[Block 1]
  block2[Block 2]

Different widths

block
  columns 1
  block1[Block 1]
  
  block
     columns 2
     block2[Block 2]
     block3[Block 3]
  end %% End the compound block

Arrows

block
  columns 3
  block1[Block 1]
  <==>
  block2[Block 2]

or (equivalent)

block
  columns 3
  block1[Block 1] <==>  block2[Block 2]

Vertical arrow

block
  columns 1
  block1[Block 1]
  ^==v
  block2[Block 2]

Auto columns

Amount of columns are automatically calculated. So specifying it is redundant.

The only scenario where we would need to specify this columns 'H' is where we have some other default for the whole graph, e.g.

mermaid.initialize({
  theme: 'default',
  block: {
    columns: 3,
  },
});

and only then we would redefine this behavior for specific bock

block-beta

block
  block app
    columns auto %% or
    columns H %% or
    columns 5 
  end
end

I found auto keyword to be more descriptive than H letter. May be columns 0 is ok as a default value too