* Implement Integer/show

Relates to #49

* Implement Double/show

Relates to #49

* Implement Natural/show

* Rename exprFXX variables to reflect the meaning

The previous tests for `build . fold` fusion for `Optional` values would
succeed even without f...

* Move test utils into separate module and use custom assertions

* Implement Natural/toIntege...

This change updates the test to test Dhall source code so that we're
exercising the system from...

You can now escape an field or variable name using backticks, like this:

```haskell
let ...

This adds support for unions by just stripping the tag

- Defines a new primitive `OptionalFold`
- Implements normalization:
- inlining of Optional/...

Part of #31, requested by @scott-fleischman

You can now use `-` in identifier names for all but...

Useful to see which version of `dhall` you are currently using.

The original reason for permitting `(` and `)` in paths was due to
Dhall's origins as a fork of ...

The expected use of this operator is to update a record. For example,
you can provide a record...

`dhall-to-nix` accidentally displays `ExitSuccess` in its `--help`
output because it prints all ...

`dhall-to-nix` accidentally displays `ExitSuccess` in its `--help`
output because it prints all ...

* Add support for importing paths as raw `Text`

Part of #23

You can now add ` as Text` to ...

... as requested by @newhoggy in #23

Consider the following Haskell program:

```
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE Der...

Consider the following program which marshals a Dhall record into Haskell:

```haskell
{-# LANGU...

Now this code:

\(x : Natural) -> x : Natural

... will be treated as equivalent to this...

Older pre-release versions of `dhall` used to
translate Haskell records to sum-types even if
t...

You can now use `env:NAME` to syntax to import an environment variable named
`NAME`

This change updates parsing errors to adopt the same format as a type error,
including a helpful...

You can now write expressions like these:

```
{ foo = 1, bar = 2,}
```

```
[1,2,3,]
```

The `exprD` parser for function application was unnecessarily backtracking when
parsing the firs...

This adds a new `deriveAuto` utility that you can customize with
`InterpretOptions` in order to...

README: update tutorial pointer to latest version

Also added `CHANGELOG.md`

We *can* auto-generate `Interpret` instances for sum types

Generalize type of expression parser

`trifecta` already depends on `lens`, so using `microlens` does not
actually trim down the depen...

`hnix` has a `base >= 4.9` requirement which prevents building with
older version of GHC

`hnix` has a `base >= 4.9` requirement which prevents building with
older version of GHC