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.

Goals

I have some immediate goals I'm trying to achieve with this syntax:

• Everything is strings (except numbers, functions, and data structures). There is no symbol type, atom type, keyword type, etc... they're all just strings.

• There is no defmacro. Macro creation and usage is simply an inherent feature of the language syntax.

Walkthrough

This is a number which evalutates to 5:

5

This is 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. A string beginning with : is evaluated to whatever it references. This evaluates to a function which adds its arguments:

":+"

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

(":+" 1 2)

A list prefixed with a : calls the first element as a function with the rest of the elements as arguments. This evaluates to the number 5:

:(":+" 1 2)

A bare string (lacking in ") is a shortcut for that string prefixed by a :. This is equivalent to the above:

:(+ 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. Note the . instead of :. We'll cover that in a bit. This defines a variable foo which evaluates to the string "bar":

.(def foo "bar")

This defines a variable incr which evaluates to a function which adds one to its argument:

.(def incr
    :(fn [x]
        :(+ x 1)))

This uses defn as 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))