rust/src/lib/getopts.rs
2011-07-27 15:54:33 +02:00

268 lines
8.0 KiB
Rust

/* Simple getopt alternative. Construct a vector of options, either by using
* reqopt, optopt, and optflag or by building them from components yourself,
* and pass them to getopts, along with a vector of actual arguments (not
* including argv[0]). You'll either get a failure code back, or a match.
* You'll have to verify whether the amount of 'free' arguments in the match
* is what you expect. Use opt_* accessors (bottom of the file) to get
* argument values out of the match object.
*/
import option::some;
import option::none;
export opt;
export reqopt;
export optopt;
export optflag;
export optflagopt;
export optmulti;
export getopts;
export getopts_ivec;
export result;
export success;
export failure;
export match;
export fail_;
export fail_str;
export opt_present;
export opt_str;
export opt_strs;
export opt_maybe_str;
export opt_default;
tag name { long(str); short(char); }
tag hasarg { yes; no; maybe; }
tag occur { req; optional; multi; }
type opt = {name: name, hasarg: hasarg, occur: occur};
fn mkname(nm: str) -> name {
ret if str::char_len(nm) == 1u {
short(str::char_at(nm, 0u))
} else { long(nm) };
}
fn reqopt(name: str) -> opt {
ret {name: mkname(name), hasarg: yes, occur: req};
}
fn optopt(name: str) -> opt {
ret {name: mkname(name), hasarg: yes, occur: optional};
}
fn optflag(name: str) -> opt {
ret {name: mkname(name), hasarg: no, occur: optional};
}
fn optflagopt(name: str) -> opt {
ret {name: mkname(name), hasarg: maybe, occur: optional};
}
fn optmulti(name: str) -> opt {
ret {name: mkname(name), hasarg: yes, occur: multi};
}
tag optval { val(str); given; }
type match = {opts: opt[], vals: optval[][mutable ], free: vec[str]};
fn is_arg(arg: str) -> bool {
ret str::byte_len(arg) > 1u && arg.(0) == '-' as u8;
}
fn name_str(nm: name) -> str {
ret alt nm { short(ch) { str::from_char(ch) } long(s) { s } };
}
fn find_opt(opts: &opt[], nm: name) -> option::t[uint] {
let i = 0u;
let l = ivec::len[opt](opts);
while i < l { if opts.(i).name == nm { ret some[uint](i); } i += 1u; }
ret none[uint];
}
tag fail_ {
argument_missing(str);
unrecognized_option(str);
option_missing(str);
option_duplicated(str);
unexpected_argument(str);
}
fn fail_str(f: fail_) -> str {
ret alt f {
argument_missing(nm) { "Argument to option '" + nm + "' missing." }
unrecognized_option(nm) { "Unrecognized option: '" + nm + "'." }
option_missing(nm) { "Required option '" + nm + "' missing." }
option_duplicated(nm) {
"Option '" + nm + "' given more than once."
}
unexpected_argument(nm) {
"Option " + nm + " does not take an argument."
}
};
}
tag result { success(match); failure(fail_); }
fn getopts(args: vec[str], opts: vec[opt]) -> result {
// FIXME: Remove this vec->ivec conversion.
let args_ivec = ~[];
let opts_ivec = ~[];
for arg: str in args { args_ivec += ~[arg]; }
for o: opt in opts { opts_ivec += ~[o]; }
ret getopts_ivec(args_ivec, opts_ivec);
}
fn getopts_ivec(args: &str[], opts: &opt[]) -> result {
let n_opts = ivec::len[opt](opts);
fn f(x: uint) -> optval[] { ret ~[]; }
let vals = ivec::init_fn_mut[optval[]](f, n_opts);
let free: vec[str] = [];
let l = ivec::len[str](args);
let i = 0u;
while i < l {
let cur = args.(i);
let curlen = str::byte_len(cur);
if !is_arg(cur) {
free += [cur];
} else if (str::eq(cur, "--")) {
let j = i + 1u;
while j < l { free += [args.(j)]; j += 1u; }
break;
} else {
let names;
let i_arg = option::none[str];
if cur.(1) == '-' as u8 {
let tail = str::slice(cur, 2u, curlen);
let eq = str::index(tail, '=' as u8);
if eq == -1 {
names = ~[long(tail)];
} else {
names = ~[long(str::slice(tail, 0u, eq as uint))];
i_arg =
option::some[str](str::slice(tail, (eq as uint) + 1u,
curlen - 2u));
}
} else {
let j = 1u;
names = ~[];
while j < curlen {
let range = str::char_range_at(cur, j);
names += ~[short(range.ch)];
j = range.next;
}
}
let name_pos = 0u;
for nm: name in names {
name_pos += 1u;
let optid;
alt find_opt(opts, nm) {
some(id) { optid = id; }
none. { ret failure(unrecognized_option(name_str(nm))); }
}
alt opts.(optid).hasarg {
no. {
if !option::is_none[str](i_arg) {
ret failure(unexpected_argument(name_str(nm)));
}
vals.(optid) += ~[given];
}
maybe. {
if !option::is_none[str](i_arg) {
vals.(optid) += ~[val(option::get(i_arg))];
} else if (name_pos < ivec::len[name](names) ||
i + 1u == l || is_arg(args.(i + 1u))) {
vals.(optid) += ~[given];
} else { i += 1u; vals.(optid) += ~[val(args.(i))]; }
}
yes. {
if !option::is_none[str](i_arg) {
vals.(optid) += ~[val(option::get[str](i_arg))];
} else if (i + 1u == l) {
ret failure(argument_missing(name_str(nm)));
} else { i += 1u; vals.(optid) += ~[val(args.(i))]; }
}
}
}
}
i += 1u;
}
i = 0u;
while i < n_opts {
let n = ivec::len[optval](vals.(i));
let occ = opts.(i).occur;
if occ == req {
if n == 0u {
ret failure(option_missing(name_str(opts.(i).name)));
}
}
if occ != multi {
if n > 1u {
ret failure(option_duplicated(name_str(opts.(i).name)));
}
}
i += 1u;
}
ret success({opts: opts, vals: vals, free: free});
}
fn opt_vals(m: match, nm: str) -> optval[] {
ret alt find_opt(m.opts, mkname(nm)) {
some(id) { m.vals.(id) }
none. { log_err "No option '" + nm + "' defined."; fail }
};
}
fn opt_val(m: match, nm: str) -> optval { ret opt_vals(m, nm).(0); }
fn opt_present(m: match, nm: str) -> bool {
ret ivec::len[optval](opt_vals(m, nm)) > 0u;
}
fn opt_str(m: match, nm: str) -> str {
ret alt opt_val(m, nm) { val(s) { s } _ { fail } };
}
fn opt_strs(m: match, nm: str) -> vec[str] {
let acc: vec[str] = [];
for v: optval in opt_vals(m, nm) {
alt v { val(s) { acc += [s]; } _ { } }
}
ret acc;
}
fn opt_strs_ivec(m: match, nm: str) -> str[] {
let acc: str[] = ~[];
for v: optval in opt_vals(m, nm) {
alt v { val(s) { acc += ~[s]; } _ { } }
}
ret acc;
}
fn opt_maybe_str(m: match, nm: str) -> option::t[str] {
let vals = opt_vals(m, nm);
if ivec::len[optval](vals) == 0u { ret none[str]; }
ret alt vals.(0) { val(s) { some[str](s) } _ { none[str] } };
}
/// Returns none if the option was not present, `def` if the option was
/// present but no argument was provided, and the argument if the option was
/// present and an argument was provided.
fn opt_default(m: match, nm: str, def: str) -> option::t[str] {
let vals = opt_vals(m, nm);
if ivec::len[optval](vals) == 0u { ret none[str]; }
ret alt vals.(0) { val(s) { some[str](s) } _ { some[str](def) } }
}
// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End: