Files
sex/sexc.scm
2025-06-05 17:11:30 +03:00

141 lines
3.9 KiB
Scheme

(import brev-separate
(chicken pretty-print)
(chicken process-context)
(chicken string)
fmt
fmt-c
getopt-long
srfi-1 ; list routines
tree)
(define (unkebabify sym)
(string->symbol
(string-translate (symbol->string sym) #\- #\_)))
(define (atom-to-fmt-c atom)
(case atom
((fn) '%fun)
((var) '%var)
((begin) '%begin)
((pointer) '%pointer)
((array) '%array)
(([]) 'vector-ref)
((include) '%include)
((cast) '%cast)
(else
(if (symbol? atom)
(unkebabify atom)
atom))))
(define (tree-finder symbol)
(lambda (node)
(or (and (tree? node)
(eq? (car node) symbol))
#f)))
(define (walk-generic form)
(let loop ((tree (tree-map atom-to-fmt-c form)))
(let ((unquote-form (tree-find (tree-finder 'unquote) tree #f)))
(if unquote-form
(let ((inv (invert-tree tree)))
(loop (tree-replace inv unquote-form (eval (cadr unquote-form)))))
tree))))
(define (walk-function form static)
(if static
(list 'static (walk-generic form))
(walk-generic (cdr form))))
(define (walk-sex-tree form)
(case (car form)
((fn) (walk-function form #t))
((pub) (walk-function form #f))
((template) '()) ; TODO
((struct) (walk-generic form))
(else (walk-generic form))))
(define (process-form form)
(case (car form)
((define)
(eval form) '())
(else
(walk-sex-tree form))))
(define (process-raw-forms raw-forms acc)
(if (null? raw-forms) (filter (fn (not (null? x)))
(reverse acc))
(process-raw-forms (cdr raw-forms)
(cons (process-form (car raw-forms))
acc))))
(define (read-forms acc)
(let ((r (read)))
(if (eof-object? r) (reverse acc)
(read-forms (cons r acc)))))
(define (emit-c forms)
(map (lambda (form)
(fmt #t (c-expr form))
(fmt #t "\n"))
forms))
;;; Main function facilities
(define opts-grammar
`((output "Write output to file"
(required #f)
(value #t)
(single-char #\o))
(help "Show this help"
(required #f)
(value #f)
(single-char #\h))
(macro-expand "Emit macro-expanded Sex code instead of C"
(required #f)
(value #f)
(single-char #\m))))
(define (print-help)
(fmt #t "Usage: sexc [OPTIONS] [FILE]\n")
(fmt #t "Options: -o, --output <file> Write output to file. If omitted, write to stdout\n")
(fmt #t " -h, --help Show this help\n")
(fmt #t " -m, --macro-expand Emit macro-expanded Sex code instead of C\n"))
(define (help-arg? args)
(assoc 'help args))
(define (get-arg args arg-name default)
(let ((arg (assoc arg-name args)))
(if arg (cdr arg)
default)))
(define (get-input-file args)
(let ((rest-args (assoc '@ args)))
(if (= 1 (length rest-args))
'stdin
(cadr rest-args))))
(define (main)
(let* ((raw-args (command-line-arguments))
(args (getopt-long raw-args
opts-grammar))
(output (get-arg args 'output 'stdout))
(help (help-arg? args))
(input (get-input-file args)))
(if help (print-help)
(let* ((raw-forms
(if (eq? input 'stdin)
(read-forms (list))
(with-input-from-file input
(lambda () (read-forms (list))))))
(sex-forms (process-raw-forms raw-forms (list))))
(if (get-arg args 'macro-expand #f)
(map pp sex-forms)
(if (not (eq? output 'stdout))
(with-output-to-file output
(lambda ()
(emit-c sex-forms)))
(emit-c sex-forms)))))))
(main)