ref: 60eafd49a8e2a67d82ad1e9f5d0618003c6c4cec
dir: /lib/zuo/config.zuo/
#lang zuo/base
(provide config-file->hash)
(define (config-file->hash path [vars (hash)])
(unless (path-string? path) (arg-error 'config->hash "path string" path))
(unless (hash? vars) (arg-error 'config->hash "hash table" vars))
(define content (file->string path))
(define no-cr-content (string-join (string-split content "\r") ""))
(define lines (string-split (string-join (string-split no-cr-content "\\\n") "") "\n"))
(define config
(foldl (lambda (line accum)
(define positions ; (list var-start var-end =-pos) or #f
(let loop ([i 0] [start #f] [end #f])
(cond
[(= i (string-length line)) #f]
[else
(let ([c (string-ref line i)])
(cond
[(= (char "=") c) (and start (list start (or end i) i))]
[(or (= (char "_") c)
(and (<= (char "a") c)
(<= c (char "z")))
(and (<= (char "A") c)
(<= c (char "Z")))
(and (<= (char "0") c)
(<= c (char "9"))))
(and (not end)
(loop (+ i 1) (or start i) #f))]
[(= (char " ") c)
(if start
(loop (+ i 1) start (or end i))
(loop (+ i 1) #f #f))]
[else #f]))])))
(cond
[positions
(define var (string->symbol (substring line (car positions) (cadr positions))))
(define rhs (substring line (+ (list-ref positions 2) 1) (string-length line)))
(hash-set accum var (string-trim (remove-makefile-comment rhs)))]
[else accum]))
(hash)
lines))
(foldl (lambda (key config)
(hash-set config key (hash-ref vars key) ))
config
(hash-keys vars)))
(define (remove-makefile-comment s)
(define l (string-split s "#"))
(cond
[(= (length l) 1) s]
[else
;; A `\` just before `#` escapes the `#`
(let loop ([l l])
(cond
[(null? l) ""]
[else
(let* ([s (car l)]
[len (string-length s)])
(cond
[(= len 0) ""]
[(= (char "\\") (string-ref s (- len 1)))
(~a (substring s 0 (- len 1))
"#"
(loop (cdr l)))]
[else s]))]))]))