Attention: This repo is opsolete. Take a look at https://github.com/ArminKleinert/NeonLyra instead.
Lyra is a lisp I make for fun and learning.
Current version: 0.8.1
This project has been superseded by Neon Lyra (https://github.com/ArminKleinert/NeonLyra)
- The top goal is to finish something simple. The project will be slowly iterated upon.
- Most functions will be implemented in Lyra itself if possible.
- Simplicity > performance
- Having fun
- Different numeric types: Integer and Float
- Macros
- Tail recursion
- Access to the environment for people who know what they are doing.
- Basic implementation for maps.
- Basic implementation for user-defined types. (Description far below)
- Many TODOs :D
- Basic numbers: Integer, Float
- String
- Cons (car, cdr)
- Boolean (#t, #f)
- Function
- Vector
- Map
(define <symbol> <value>)
Assigns a value to a symbol.
(lambda (<args>) <body>)
A function.
(define (<name> <args>) <body>)
Short for (define <name> (lambda (<args>) <body>))
.
(if <predicate> <then> <else>)
Common if. Executes the predicate. If it is true, evaluates then
, if not, evaluates else
.
(cond <clauses>)
Each clause has the form (<predicate> <expr>)
.
Example:
(cond ((vector? e) (foo e))
((list? e) (bar e))
(#t (baz e)))
Notice! Any function marked with '!' should only be used if you know what
you are doing!
Natively implemented:
Function | Arity | Description
---------------------+-------+------------------------------------------------------------
define | any | Adds a variable or function to the global (!) environment.
lambda | any | Creates a new anonymous function.
let* | >=1 | Adds a single variable to the local environment.
let | >=1 | Like let* but for multiple variables.
| |
= | 2 | Checks 2 values for equality.
< | 2 | Checks whether the first argument is less than the second.
> | 2 | Checks whether the second argument is less than the first.
| |
+ | 2 | Addition. Adding to a string also works.
- | 2 | Subtraction
* | 2 | Multiplication
/ | 2 | Division
% | 2 | Modulo
& | 2 | Bitwise and
^ | 2 | Bitwise xor
| |
list | any | Creates a list ending with nil.
car | 1 | Gets the car of a pair.
cdr | 1 | Gets the cons of a pair.
cons | 2 | Creates a new cons.
set-car! | 2 | Sets the car of a cons. (Unsafe!)
set-cdr! | 2 | Sets the cdr of a cons. (Unsafe!)
| |
null? | 1 | Checks equality to nil.
cons? | 1 | Checks whether the value is a cons.
int? | 1 | Checks whether the value is a int.
float? | 1 | Checks whether the value is a float.
string? | 1 | Checks whether the value is a string.
vector? | 1 | Checks whether the value is a vector.
symbol? | 1 | Checks whether the value is a symbol.
| |
bit-match? | 2 | Takes 2 integers as arguments. If either of them is nil,
| | return #f. Otherwise, return the result of the following:
| | (= (& (first args) (second args)) (first args))
| |
int | 1 | Tries to convert a value to an int.
float | 1 | Tries to convert a value to a float.
string | 1 | Tries to convert a value to a string.
bool | 1 | Triess to convert a value to a bool.
| |
sprint! | 2 | Prints a string (2nd argument) to a stream (1st argument).
sread! | 1 | Reads a string from a stream.
slurp! | 1 | Reads all contents of a file into a string.
spit! | 2 | Writes a string (2nd argument) into a file (1st argument).
| |
eval! | 1 | Evaluates an expression.
parse | 1 | Parses a string into an expression.
| |
env! | 0 | Gets the current (local) environment. Highly unsafe.
global-env! | 0 | Like env!, but ignores the local environment. Also unsafe.
| |
time! | 0 | Get the current time in seconds as a floating point number.
measure | 2 | Runs a function (2nd argument) n (1st argument) times.
Untested: sprint!, sread!, slurp!, spit!, env!
Core functions:
Function | Arity | Description
---------------------+-------+------------------------------------------------------------
eq? | 2 | Alias for =
eql? | 2 | Alias for =
<= | 2 | Less than or equal to.
>= | 2 | Greater than or equal to.
load! | 1 | Imports another source file by filename.
require! | 1 | Alias for load!
import! | 1 | Alias for load!
comment | any | A macro which ignores its body.
first | 1 | First element of a collection.
second | 1 | Second element of a collection.
third | 1 | Third element of a collection.
rest | 1 | Rest element of a collection.
ffirst | 1 | Alias for (first (first e))
sfirst | 1 | Alias for (second (first e))
rfirst | 1 | Alias for (rest (first e))
length | 1 | Length of a collection. 0 for atomic types.
begin | 2 | Takes two arguments and executes them both.
| |
deprioritise-helper! | | Helper for deprioritise!. Do not use or override!
deprioritise! | 1 | Moves a variable (if found) to the end of the global
| | environment.
index-in-env-helper! | | Helper for index-in-env!. Do not use or override!
index-in-env! | 1 | Finds the index of a variable in the global environment.
| | -1 if the symbol could not be found.
| |
empty? | 1 | Same as null?
inc | 1 | Increment a number by 1
dec | 1 | Decrement a number by 1
nth | 2 |
and | 2 | boolean and
or | 2 | boolean or
not | 1 | boolean not
foldl | 3 |
foldr | 3 |
print! | 1 | Prints a string to stdout.
println! | 1 | Prints a string to stdout followed by a newline.
read! | 0 | Reads a string from stdin.
map | 2 |
map! | 2 | Impure map. Modifies the each element. (!)
filter | 2 |
; TODO Update the list above.
associative.lyra functions:
Function | Arity | Description
---------------------+-------+------------------------------------------------------------
map? | 1 |
make-map | 0 |
map-to-string | 1 | (Needs a re-work)
add-entry | 3 | Adds an entry to a map and returns a new map. If the key
| | already exists, it is replaced.
add-entry! | 3 | Adds or replaces an entry. The map is mutated.
remove-from-map | 2 | Removes an entry from a map and returns a new map.
remove-from-map! | 2 | Removes an entry from a map. The map is mutated.
get-value | 2 | Gets a value from the map.
Untested: filter, and, or, not, foldl, foldr, map!
Variable | Description
---------+--------------------------------------------------------------------------------
#t #f | True and false
'() | The empty list (Also called 'nil'). Serves as the terminator for normal lists.
stdin | Standard input stream.
stdout | Standard output stream.
stderr | Standard error stream.
nil | Alias for '().
- Call
add-lyra-type!
and save the value somewhere ((define my-type-id (add-lyra-type!))
) - Create a
<type>?
function. ((define (my-type? m) (type-match? (lyra-type-id m) my-type-id))
) - Call
add-type-basics!
. The function takes 3 arguments: 1 for string-conversion and 1 for equality-checks. Primitive variantsstring
andp=
can be used. - You can add more functions with
add-type-function!
; Define a new type
(define my-type-id (add-lyra-type!))
; For checking against your type.
(define (my-type? m) (type-match? (lyra-type-id m) my-type-id))
(define (my-type-to-s m) ...)
; The new type uses a custom function for string-conversion and
; the build-in function for =.
(add-type-basics! my-type-id my-type-to_s p=)
; Define a replacement for the `map` function for your type.
(define (my-type-map f m) ...)
(add-type-function! my-type-id 'map my-type-map)
; Creates a vector which carries the special id of your type
(define (make-my-type) (pvector my-type-id))
- Use the new type-system in the following functions:
=
<
>
+
-
*
/
%
&
|
bit-xor (p^)
<<
>>
reverse
->list
->vector
hash-code
int
float
A module-system to prevent messing with core-function-names. (Can easily happen when using define
)
0.1.0 The thing works.
0.2.0 Added macros and basic functions including fold, map, filter, etc.
0.3.0 Added vectors.
0.4.0 Added more numeric literals and cond.
0.5.0 Many bugfixes and maps.
0.6.0 Added user-defined types.
0.7.0 Nil is now compatible with conses.
0.8.0 Massive performance improvements by making the environment a map instead of a cons.
https://www.youtube.com/playlist?list=PLatjRac4Qo4BQ-ksFWeYUt8FL03MnJVPK