crisp is a lisp variant. Everything is a list. Functions are lists which
operate on lists.
(add 1 1) ;; => 2The first element of the list is the name of the function to call, the remaining elements are the arguments passed to the function.
Variables are scoped to within their created environment.
(defvar pi 3.14) ;; variable in global environment.
(defun foo ()
(print pi)
(defvar R 8.314) ;; variable in function-local environment.
(print R))
(foo) ;; prints pi from global environment, and R from its local environment
(print R) ;; Error: R is not in the environment.A variable is a symbol which refers to a lisp object which can contain anything. Objects are dynamically typed:
- list
- symbol
- atom
- int
- float
- string
Anything with a numerical or string value is an atom: it is indivisible and can't be expanded into elements (as for lists), or followed to a referred value (as for symbols).
Not yet, patience!
The (doc o) function will print the documentation for a builtin function. Try
it in the interpreter! (doc doc)!
The standard library consists of C++ builtin functions and crisp functions
which are available to the crisp interpreter.
(defun name list &rest body)NAME is the symbol which will refer to the function body. LIST is the list of sybmols (arguments) for the function. The rest, BODY, is a list of the contents of the function.
The arguments to the function are evaluated before the function is called. If
this is not the desired behaviour, try defmacro.
(defmacro name list &rest body)NAME is the symbol which will refer to the macro body. LIST is the list of sybmols (arguments) for the macro. The rest, BODY, is a list of the contents of the macro.
The arguments to the macro are NOT evaluated before the it is called. This is
like quoting all the arguments to a function. If this is not the desired
behaviour, try defun.
(defvar name body)NAME is the symbol which will refer to value. BODY is the value of the variable.
The definition of this variable is in the same environment as it was called.
(print &rest objects)Prints to stdout the string representation of OBJECTS with no additions (no
spaces inserted between objects).
(with-open path mode name &rest body)Open a file at PATH for reading/writing/appending (depending on MODE: r/w/a). Save file descriptor in sub-environment with NAME. BODY is list of functions to be executed in sub-environment. File is closed after body is executed.
Inspired by both context management in Python and RAII in C++.