ref: b769b88bbc3e0ddcef7991e73b2582d472f08d89
dir: /libstd/optparse.myr/
use "alloc.use" use "die.use" use "extremum.use" use "fmt.use" use "option.use" use "sleq.use" use "slpush.use" use "syswrap-ss.use" use "syswrap.use" use "types.use" use "utf.use" pkg std = type optdef = struct argdesc : byte[:] /* the description for the usage */ minargs : std.size /* the minimum number of positional args */ opts : optdesc[:] /* the description of the options */ ;; type optdesc = struct opt : char arg : byte[:] desc : byte[:] optional : bool ;; type optparsed = struct opts : (char, byte[:])[:] args : byte[:][:] ;; const optparse : (optargs : byte[:][:], def : optdef# -> optparsed) const optusage : (prog : byte[:], def : optdef# -> void) ;; type optctx = struct /* public variables */ args : byte[:][:] /* data passed in */ optdef : optdef# optargs : byte[:][:] /* state */ optdone : bool /* if we've seen '--', everything's an arg */ finished : bool /* if we've processed all the optargs */ argidx : size curarg : byte[:] ;; const optparse = {args, def var ctx : optctx var parsed optinit(&ctx, args, def) while !optdone(&ctx) parsed.opts = slpush(parsed.opts, optnext(&ctx)) ;; if ctx.args.len < def.minargs put("error: expected at least %z args, got %z\n", def.minargs, ctx.args.len) optusage(ctx.optargs[0], ctx.optdef) exit(1) ;; parsed.args = ctx.args -> parsed } const optinit = {ctx, args, def ctx# = [ .optargs = args, .optdef = def, .optdone = false, .finished = false, .argidx = 0, .curarg = [][:], .args = [][:], ] next(ctx) -> ctx } const optnext = {ctx var c var arg (c, ctx.curarg) = striter(ctx.curarg) match optinfo(ctx, c) | `None: if c == 'h' || c == '?' optusage(ctx.optargs[0], ctx.optdef) exit(0) else fatal(1, "unexpected argument '%c'\n", c) ;; | `Some (true, needed): /* -arg => '-a' 'rg' */ if ctx.curarg.len > 0 arg = ctx.curarg ctx.curarg = ctx.curarg[ctx.curarg.len:] next(ctx) /* '-a rg' => '-a' 'rg' */ elif ctx.argidx < (ctx.optargs.len - 1) arg = ctx.optargs[ctx.argidx + 1] ctx.argidx++ next(ctx) elif needed put("Expected argument for %c\n", c) exit(1) ;; | `Some (false, _): arg = "" if ctx.curarg.len == 0 next(ctx) ;; ;; -> (c, arg) } const optdone = {ctx -> ctx.curarg.len == 0 && ctx.finished } const optinfo = {ctx, opt for o in ctx.optdef.opts if o.opt == opt -> `Some (o.arg.len != 0, !o.optional) ;; ;; -> `None } const next = {ctx var i for i = ctx.argidx + 1; i < ctx.optargs.len; i++ if !ctx.optdone && decode(ctx.optargs[i]) == '-' if sleq(ctx.optargs[i], "--") ctx.optdone = true else goto foundopt ;; else ctx.args = slpush(ctx.args, ctx.optargs[i]) ;; ;; :finishedopt ctx.finished = true -> false :foundopt ctx.argidx = i ctx.curarg = ctx.optargs[i][1:] -> true } const optusage = {prog, def std.put("usage: %s [-h?]", prog) for o in def.opts std.put("[-%c%s%s] ", o.opt, sep(o.arg), o.arg) ;; std.put("%s\n", def.argdesc) std.put("\t-h\tprint this help message\n") std.put("\t-?\tprint this help message\n") for o in def.opts std.put("\t-%c%s%s\t%s\n", o.opt, sep(o.arg), o.arg, o.desc) ;; } const sep = {s if s.len > 0 -> " " else -> "" ;; }