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Merged
skx merged 1 commit into from
Jul 12, 2026
Merged

Allow auto-running the (defun main .. from inception #175

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17 changes: 6 additions & 11 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -213,7 +213,8 @@ Loading .. ../test/closure2.lisp
Welcome to lisp in slisp!
Enter :quit to exit.

; loading "closure2.lisp" will produce a (defun main) now we call it.
; loading "closure2.lisp" will define (defun main)
; now we call it via the REPL:
> (main)
25
35
Expand All @@ -226,28 +227,22 @@ Enter :quit to exit.
Perhaps more interesting is that we can execute the [examples/nqueens.lisp](examples/nqueens.lisp) example, with no changes:

```
$ ./inception nqueens.lisp --repl
$ ./inception nqueens.lisp --main
Loading .. nqueens.lisp
Welcome to lisp in slisp!
Enter :quit to exit.

> (main)
8 Queens Solver for board size 8x8

Solution 1 (1 5 8 6 3 7 2 4):

Q . . . . . . .
. . . . Q . . .
. . . . . . . Q
. . . . . Q . .
. . Q . . . . .
. . . . . . Q .
. Q . . . . . .
. . . Q . . . .

..
..
```

> Here you'll see we added `--main` which automatically runs the `(main)` function our examples define.

So what are the differences between our _compiler_ and our _interpreter_? Well in some ways the interpreter is more advanced as it has support for `(quote)`, it has a symbol-type, and you can get references to functions using them. The lambdas/defuns are real standalone objects which are treated largely interchangeably and which you can print. But the biggest difference is that the compiler has a significantly larger standard-library.

The compiler prepends [stdlib.slisp](stdlib.slisp) to all programs, so you always have `map`, `filter`, etc, available. By contrast the interpreter has a very small standard library - it exposes `print`, `println`, `cons`, `list` and the special forms. It understands strings, integers, and floating-point numbers but it doesn't have a character-type.
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8 changes: 7 additions & 1 deletion examples/inception.lisp
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Expand Up @@ -349,6 +349,8 @@
(eval-defun expr env))
((= op "defvar")
(eval-defvar expr env))
((= op "defconst")
(eval-defvar expr env))
((= op "do")
(eval-do expr env))
((= op "if")
Expand Down Expand Up @@ -813,7 +815,8 @@

;; We process each named file (skipping --repl)
(map (lambda (name)
(if (!= name "--repl")
(if (and (!= name "--repl")
(!= name "--main"))
(do
(println "Loading .. " name)
(let ((handle (fopen name "r")) ; open
Expand All @@ -823,6 +826,9 @@
(run-program data))))))
(cdr args))

;; Should we auto-run (defun main) ..?
(if (member? args "--main")
(repl-execute-line "(main)"))

;; Is this REPL mode? Then run it
(if (member? args "--repl")
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