squiggle/packages/squiggle-lang/src/rescript/FunctionRegistry/README.md

# Function Registry

The function registry is a library for organizing function definitions.

The main interface is fairly constrained. Basically, write functions like the following, and add them to a big array.

```rescript
  Function.make(
    ~name="Normal",
    ~definitions=[
        FnDefinition.make(
            ~name="Normal",
            ~definitions=[
                FnDefinition.make(~name="normal", ~inputs=[FRTypeDistOrNumber, FRTypeDistOrNumber], ~run=(
                    inputs,
                    env,
                ) =>
                    inputs
                    ->Prepare.ToValueTuple.twoDistOrNumber
                    ->E.R.bind(
                    Process.twoDistsOrNumbersToDistUsingSymbolicDist(
                        ~fn=E.Tuple2.toFnCall(SymbolicDist.Normal.make),
                        ~env,
                        ~values=_,
                    ),
                    )
                    ->E.R2.fmap(Wrappers.evDistribution)
                ),
            ],
        )
    ],
  )
```

The Function name is just there for future documentation. The function defintions

## Key Files

**FunctionRegistry_Core**
Key types, internal functionality, and a `Registry` module with a `matchAndRun` function to call function definitions.

**FunctionRegistry_Library**
A list of all the Functions defined in the Function Registry.

**FunctionRegistry_Helpers**
A list of helper functions for the FunctionRegistry_Library.