[jackhill/mal.git] / docs / exercise.md

Once you have a working implementation, you may want to implement
parts of the process inside the MAL language itself. This has no other
purpose than learning the MAL language. Once it exists, a built-in
implementation will always be more efficient than a native
implementation. Also, the functions described in MAL process are
selected for educative purposes, so portability accross
implementations does not matter much.

You may easily check your answers by passing them directly to the
interpreter. They will hide the built-in functions carrying the same
names, and the usual tests (with REGRESS=1) will check them. The
`runtest.py` script provide a convenient command-line parameter to
pass a command like 'load-file' before running the testsuite.

Some solutions are given in the `examples` directory. Feel free to
submit new solutions, or new exercises.


- Implement the following functions with other built-in functions.
  - `nil?`, `true?` and `false?`
  - `empty?`
  - `sequential?`

- Implement `>`, `<=` and `>=` with `<`.

- Implement the following non-recursive functions.
  - `hash-map`
  - `list`
  - `prn`
  - `swap!`

- Implement `map` with a recursion.

- Implement the `do` special as a non-recursive function. The special
  form will hide your implementation, so in order to test it, you will
  need to give it another name and adapt the test accordingly.

- Implement `let*` as a macro that uses `fn*` and recursionn. The same
  remark applies.

- Implement `apply` as a macro.

- Implement maps using lists.
  FIXME: Is dissoc use anywhere? It makes this implememtation and the
  process more complex.

- Implement quoting within MAL.

- Implement macros within MAL.
Commit	Line	Data
0544b52f NB	1	Once you have a working implementation, you may want to implement
	2	parts of the process inside the MAL language itself. This has no other
	3	purpose than learning the MAL language. Once it exists, a built-in
	4	implementation will always be more efficient than a native
	5	implementation. Also, the functions described in MAL process are
	6	selected for educative purposes, so portability accross
	7	implementations does not matter much.
	8
	9	You may easily check your answers by passing them directly to the
	10	interpreter. They will hide the built-in functions carrying the same
	11	names, and the usual tests (with REGRESS=1) will check them. The
	12	`runtest.py` script provide a convenient command-line parameter to
	13	pass a command like 'load-file' before running the testsuite.
	14
	15	Some solutions are given in the `examples` directory. Feel free to
	16	submit new solutions, or new exercises.
	17
	18
	19	- Implement the following functions with other built-in functions.
	20	- `nil?`, `true?` and `false?`
	21	- `empty?`
	22	- `sequential?`
	23
	24	- Implement `>`, `<=` and `>=` with `<`.
	25
	26	- Implement the following non-recursive functions.
	27	- `hash-map`
	28	- `list`
	29	- `prn`
	30	- `swap!`
	31
	32	- Implement `map` with a recursion.
	33
	34	- Implement the `do` special as a non-recursive function. The special
	35	form will hide your implementation, so in order to test it, you will
	36	need to give it another name and adapt the test accordingly.
	37
	38	- Implement `let` as a macro that uses `fn` and recursionn. The same
	39	remark applies.
	40
	41	- Implement `apply` as a macro.
	42
	43	- Implement maps using lists.
	44	FIXME: Is dissoc use anywhere? It makes this implememtation and the
	45	process more complex.
	46
	47	- Implement quoting within MAL.
	48
	49	- Implement macros within MAL.