Add GetOpts module to std

Author: marijnh

src/lib/GetOpts.rs

@@ -0,0 +1,249 @@
+/* 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;
+
+tag name { long(str); short(char); }
+tag hasarg { yes; no; maybe; }
+tag occur { req; optional; multi; }
+
+type opt = rec(name name, hasarg hasarg, occur occur);
+
+fn mkname(str nm) -> name {
+    if (_str.char_len(nm) == 1u) { ret short(_str.char_at(nm, 0u)); }
+    else { ret long(nm); }
+}
+fn reqopt(str name) -> opt {
+    ret rec(name=mkname(name), hasarg=yes, occur=req);
+}
+fn optopt(str name) -> opt {
+    ret rec(name=mkname(name), hasarg=yes, occur=optional);
+}
+fn optflag(str name) -> opt {
+    ret rec(name=mkname(name), hasarg=no, occur=optional);
+}
+fn optmulti(str name) -> opt {
+    ret rec(name=mkname(name), hasarg=yes, occur=multi);
+}
+
+tag optval {
+    val(str);
+    given;
+}
+
+type match = rec(vec[opt] opts, vec[mutable vec[optval]] vals, vec[str] free);
+
+fn is_arg(str arg) -> bool {
+    ret _str.byte_len(arg) > 1u && arg.(0) == '-' as u8;
+}
+fn name_str(name nm) -> str {
+    alt (nm) {
+        case (short(?ch)) {ret _str.from_char(ch);}
+        case (long(?s)) {ret s;}
+    }
+}
+
+// FIXME rustboot workaround
+fn name_eq(name a, name b) -> bool {
+    alt (a) {
+        case (long(?a)) {
+            alt (b) {
+                case (long(?b)) { ret _str.eq(a, b); }
+                case (_) { ret false; }
+            }
+        }
+        case (_) { if (a == b) { ret true; } else {ret false; } }
+    }
+}
+fn find_opt(vec[opt] opts, name nm) -> option.t[uint] {
+    auto i = 0u;
+    auto l = _vec.len[opt](opts);
+    while (i < l) {
+        if (name_eq(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);
+}
+
+fn fail_str(fail_ f) -> str {
+    alt (f) {
+        case (argument_missing(?nm)) {
+            ret "Argument to option '" + nm + "' missing.";
+        }
+        case (unrecognized_option(?nm)) {
+            ret "Unrecognized option: '" + nm + "'.";
+        }
+        case (option_missing(?nm)) {
+            ret "Required option '" + nm + "' missing.";
+        }
+        case (option_duplicated(?nm)) {
+            ret "Option '" + nm + "' given more than once.";
+        }
+    }
+}
+
+tag result {
+    success(match);
+    failure(fail_);
+}
+
+fn getopts(vec[str] args, vec[opt] opts) -> result {
+    auto n_opts = _vec.len[opt](opts);
+    fn empty_(uint x) -> vec[optval]{ret _vec.empty[optval]();}
+    auto f = empty_;
+    auto vals = _vec.init_fn_mut[vec[optval]](f, n_opts);
+    let vec[str] free = vec();
+
+    auto l = _vec.len[str](args);
+    auto i = 0u;
+    while (i < l) {
+        auto cur = args.(i);
+        auto curlen = _str.byte_len(cur);
+        if (!is_arg(cur)) {
+            _vec.push[str](free, cur);
+        } else if (_str.eq(cur, "--")) {
+            free += _vec.slice[str](args, i + 1u, l);
+            break;
+        } else {
+            auto names;
+            auto i_arg = option.none[str];
+            if (cur.(1) == '-' as u8) {
+                auto tail = _str.slice(cur, 2u, curlen);
+                auto eq = _str.index(tail, '=' as u8);
+                if (eq == -1) {
+                    names = vec(long(tail));
+                } else {
+                    names = vec(long(_str.slice(tail, 0u, eq as uint)));
+                    i_arg = option.some[str]
+                        (_str.slice(tail, (eq as uint) + 1u, curlen - 2u));
+                }
+            } else {
+                auto j = 1u;
+                names = vec();
+                while (j < curlen) {
+                    auto range = _str.char_range_at(cur, j);
+                    _vec.push[name](names, short(range._0));
+                    j = range._1;
+                }
+            }
+            auto name_pos = 0u;
+            for (name nm in names) {
+                name_pos += 1u;
+                auto optid;
+                alt (find_opt(opts, nm)) {
+                    case (some[uint](?id)) {optid = id;}
+                    case (none[uint]) {
+                        ret failure(unrecognized_option(name_str(nm)));
+                    }
+                }
+                alt (opts.(optid).hasarg) {
+                    case (no) {
+                        _vec.push[optval](vals.(optid), given);
+                    }
+                    case (maybe) {
+                        if (!option.is_none[str](i_arg)) {
+                            _vec.push[optval](vals.(optid),
+                                              val(option.get[str](i_arg)));
+                        } else if (name_pos < _vec.len[name](names) ||
+                                   i + 1u == l || is_arg(args.(i + 1u))) {
+                            _vec.push[optval](vals.(optid), given);
+                        } else {
+                            i += 1u;
+                            _vec.push[optval](vals.(optid), val(args.(i)));
+                        }
+                    }
+                    case (yes) {
+                        if (!option.is_none[str](i_arg)) {
+                            _vec.push[optval](vals.(optid),
+                                              val(option.get[str](i_arg)));
+                        } else if (i + 1u == l) {
+                            ret failure(argument_missing(name_str(nm)));
+                        } else {
+                            i += 1u;
+                            _vec.push[optval](vals.(optid), val(args.(i)));
+                        }
+                    }
+                }
+            }
+        }
+        i += 1u;
+    }
+
+    i = 0u;
+    while (i < n_opts) {
+        auto n = _vec.len[optval](vals.(i));
+        auto 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(rec(opts=opts, vals=vals, free=free));
+}
+
+fn opt_vals(match m, str nm) -> vec[optval] {
+    alt (find_opt(m.opts, mkname(nm))) {
+        case (some[uint](?id)) { ret m.vals.(id); }
+        case (none[uint]) {
+            log_err "No option '" + nm + "' defined.";
+            fail;
+        }
+    }
+}
+fn opt_val(match m, str nm) -> optval {
+    ret opt_vals(m, nm).(0);
+}
+fn opt_present(match m, str nm) -> bool {
+    ret _vec.len[optval](opt_vals(m, nm)) > 0u;
+}
+fn opt_str(match m, str nm) -> str {
+    alt (opt_val(m, nm)) {
+        case (val(?s)) { ret s; }
+        case (_) { fail; }
+    }
+}
+fn opt_strs(match m, str nm) -> vec[str] {
+    let vec[str] acc = vec();
+    for (optval v in opt_vals(m, nm)) {
+        alt (v) {
+            case (val(?s)) { _vec.push[str](acc, s); }
+            case (_) {}
+        }
+    }
+    ret acc;
+}
+fn opt_maybe_str(match m, str nm) -> option.t[str] {
+    auto vals = opt_vals(m, nm);
+    if (_vec.len[optval](vals) == 0u) { ret none[str]; }
+    alt (vals.(0)) {
+        case (val(?s)) { ret some[str](s); }
+        case (_) { ret none[str]; }
+    }
+}
+
+// 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 .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End:

src/lib/std.rc

@@ -70,6 +70,7 @@ mod ebml;
 mod UFind;
 mod ExtFmt;
 mod Box;
+mod GetOpts;
 
 // Local Variables:
 // mode: rust;