Update property of a node

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1

Is it possible to update the value of a node with a command or action ?
below an illustration about what I mean.

'stock': Number 'units'
'mutate': number 'units'
'mutation': stategroup (
  '+' { }
  '-' { }
)
'stock': number 'units' = swich .'mutation' (
  |'+' => sum ( .'stock', .'mutate' )
  |'-' => sum ( .'stock', - .'mutate' )
)
2

To update properties of a node using actions (or commands), you could do something like this:

	'stock items': collection ['item'] {
		'item': text
		'stock': number 'units'
		'mutate': action {
			'mutation': number 'units'
		} => update (
			'stock' = sum (
				.'stock',
				@ .'mutation'
			)
		)
	}

I hope this answers your question, because “update the value of a node” is unclear to me. Properties of a node can be updated. E.g. texts and numbers, but not the node itself.

3

Thanks for the correction, i did mean “update the value property of a node”
This indeed answered my question, thanks