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# Language spec
- Dynamically and weakly typed, interpreted
- Impure functions marked with ! (convention), purity is tracked by the interpreter
- Boolean functions marked with ? (convention)
- Loops implemented with recursion
## Value types
Number -3.14
Symbol PI
Tag :tag
Boolean true
String "foobar"
Vector [1 2 3]
Hash map { a 1 b 2 }
Function (\[x y] (+ x y))
## Syntax
### Function calls
A sequence of values surrounded by parens is considered a function call In a function call, the first element must evaluate to a function value. The function will be invoked with the rest of the elements as arguments to the function. A function call with no arguments evaluates to the function itself.
### Function definition
Calling the builtin variadic function `\` constructs a new function. The first argument must be a vector of symbols (parameter list). The rest of the arguments form the function body. The evaluated value of the last argument is returned as the return value of the function.
Memoized pure functions can be created with a special `let memo`-binding:
(let memo f (\[x] x))
Impure functions can be created with the builtin `\!`.
### Currying
Functions are automatically curried
E.g.
(let f1 (\[x y] (+ x y)))
(let f2 (\[x] (\[y] (+ x y))))
; f1 equivalent to f2
## Some builtin functions
`let`
Evaluates second argument and stores the resulting value in the environment.
(let sum2 (\[x y] (+ x y)))
`\`
Defines a function.
(\[x y] (+ x y))
`print!`
Prints a value without a newline.
(print! PI)
`match`
Matches first argument (value) to even positioned arguments (matchers). On match (at position i), evaluates the odd positioned argument (branch) right after it (at position i + 1).
(match (sum2 1 1)
2 (do-thing)
3 (do-other-thing)
otherwise (do-else))
`head`
Gets the first element of a vector.
(head vec)
`tail`
Drops the first element of a vector.
(tail vec)
`prepend`
Pushes the first argument to the front of the second argument (vector).
(prepend x xs)
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