ginger/README.md

# Ginger

A lisp-like language built on the go programming language. The ideas are still a
work-in-progress, and this repo is where I'm jotting down my notes.

# Walkthrough

This is a number which evalutates to 5:

```
5
```

This is a string, as it contains no whitespace:

```
ImJustAString
```

This is also a string, it can contain anything:

```
"! I'm the king of the world !"
```

This is a list. It evaluates to a linked-list of four strings:

```
(a b c d)
```

This is a vector of those same elements. It's like a list, but has some slightly
different properties. We'll mostly be using lists:

```
[a b c d]
```

This is a string

```
+
```

`:` is the evaluator. This evaluates to a function which adds its arguments:

```
:+
```

This evaluates to list whose elements are a function and two numbers:

```
(:+ 1 2)
```

This evaluates to the number 5:

```
:(:+ 1 2)
```

The `fn` function can be used to define a new function. This evaluates to an
anonymous function which adds one to its argument and returns it:

```
:(:fn [x]
    :(:+ :x 1))
```

The `def` function can be used to bind some value to a new variable:

```
:(:def foo bar)
# Now :foo will evaluate to the string bar

:(:def incr
    (:fn [x]
        :(:+ :x 1)))
# Now :incr will evaulate to a function which adds 1 to its argument

#defn is a shortcut for the above
:(:defn incr [x]
    :(:+ :x 1))
```

There are also maps. A map's keys can be any value(?). A map's values can be any
value. This evaluates to a map with 2 key/val pairs:

```
{ foo :foo
  bar (:incr 4) }
```

`.` is the half-evaluator. It only works on lists, and runs the function given
in the first argument with the unevaluated arguments (even if they have `:` in
front). You can generate new code to run on the fly (macros) using the normal
`fn`. This evaluates to a `let`-like function, except it forces you to use the
capitalized variable names in the body (utterly useless):

```
:(:defn caplet [mapping body...]
    # elem-map maps over every element in a list, embedded or otherwise
    ::(:elem-map
        :(:fn [x]
            :(:if (mapping :(:slice :x 1))
                (capitalize :x)
                :x))
        :body))

#Usage
.(:caplet [foo "this is foo"
           dog "this is dog"]
    :(:println :Foo)
    :(:println :Dog))
```