> For the complete documentation index, see [llms.txt](https://altaisoft.gitbook.io/ysv/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://altaisoft.gitbook.io/ysv/language/basics.md).

# Basics

Introduction to ysv configuration language

## Transformations

Everything that `ysv` is doing to the data is called a **transformation**. A transformation basicly takes data from somewhere (or from previous transformation in the chain) and does something to that data.

For example, `input` transformation just fetches a value from the input dataset, and `uppercase` - naturally - uppercases a value it receives.

For every column in the output dataset, you can write down a chain of transformations. Like this:

```yaml
version: 1
columns:
  - input: CompanyType
  - uppercase
  - replace:
    "LTD": "LIMITED"
    "INC": "INCORPORATED"
```

Transformations are executed topdown, one by one.

## Data Types

Values that `ysv` is working on are typed. Supported types are:

* `String` (the default type)
* `Integer`
* `Float`
* `Date`
* `Boolean`
* `List`

This feature is still in development, and more use cases will be added a bit later, but for now consider this example:

```yaml
columns:
  date:
    - input: "Transaction Date"
    - date: "%m/%d/%Y"
```

This transformation will attempt to parse the date from input dataset. The default format of outputting the date is `YYYY-MM-DD`, and that's what will be printed in the output.