# mutate (10-mutate.com)

To change or alter something. A person might say they want to mutate a plan, meaning they want to revise or update it.

## What a model may hear
- modify in place (programming, especially JavaScript and state management): assume the user wants to change an existing data structure directly rather than create a new one
- GraphQL mutation (GraphQL API design): interpret the request as a write operation to create, update, or delete server data
- genetic mutation (biology, bioinformatics): treat the context as involving DNA, genes, or evolutionary algorithms
- database mutation (distributed systems and databases): assume the user is referring to a logged change event or a write to a replicated store

## Where people and models part ways
- Says: "mutate the list"
  Means: change what items are in the list
  May be taken as: assume the user wants to modify the array in place with push/pop rather than return a new array
  Say instead: "return a new list with the changes, do not modify the original"
- Says: "mutate the document"
  Means: edit the file
  May be taken as: assume a MongoDB update operation or a GraphQL mutation schema
  Say instead: "edit and save the file, not a database record"
- Says: "mutate the design"
  Means: try a different version
  May be taken as: invoke a genetic algorithm or evolutionary optimization process
  Say instead: "create a variation of the design"

## Tips
- Say 'return a new copy' if you do not want in-place modification.
- Specify 'GraphQL mutation' explicitly if that is what you mean.
- Use 'edit' or 'change' instead of 'mutate' when talking about documents or files.
- Say 'evolve' or 'breed' for genetic algorithm contexts to avoid confusion.
- Add 'without side effects' if you want functional-style immutable behavior.

## Often confused with
- modify: neutral, does not imply in-place vs. copy
- update: often implies a database or persistent store write
- transform: usually implies a new result, not changing the original
- evolve: suggests gradual or generational change, often biological
- alter: general synonym, less technical baggage
- setState: React-specific, may or may not mutate depending on version