Rename optparse.h to cli.h

1 files changed, 159 insertions, 0 deletions

diff --git a/lib/cli/optparse.c b/lib/cli/optparse.c
new file mode 100644
index 0000000..ce688cf
--- /dev/null
+++ b/lib/cli/optparse.c
@@ -0,0 +1,159 @@
+#include <stdio.h>
+#include <string.h>
+
+#include "cli.h"
+#include "macros.h"
+#include "mbstring.h"
+
+#define CLI_MSG_INVALID "invalid option"
+#define CLI_MSG_MISSING "option requires an argument"
+#define CLI_MSG_TOOMANY "option takes no arguments"
+
+#define IS_DASHDASH(s) ((s).len == 2 && (s).p[0] == '-' && (s).p[1] == '-')
+#define IS_LONGOPT(s)  ((s).len >= 3 && (s).p[0] == '-' && (s).p[1] == '-')
+#define IS_SHORTOPT(s) ((s).len >= 2 && (s).p[0] == '-' && (s).p[1] != '-')
+
+#define error(st, msg, x)                                                      \
+	_Generic((x), struct u8view: error_s, rune: error_r)((st), (msg), (x))
+
+static rune error_r(struct optparser *, const char *, rune);
+static rune error_s(struct optparser *, const char *, struct u8view);
+static rune shortopt(struct optparser *, const struct cli_option *, size_t);
+
+rune
+optparse(struct optparser *st, const struct cli_option *opts, size_t nopts)
+{
+	st->errmsg[0] = '\0';
+	st->optarg = (struct u8view){};
+
+	struct u8view opt = {.p = st->_argv[st->optind]};
+	if (opt.p == nullptr)
+		return 0;
+	opt.len = strlen(opt.p);
+
+	if (IS_DASHDASH(opt)) {
+		st->optind++;
+		return 0;
+	}
+	if (IS_SHORTOPT(opt))
+		return shortopt(st, opts, nopts);
+	if (!IS_LONGOPT(opt))
+		return 0;
+
+	st->_subopt = 0;
+	st->optind++;
+
+	/* Skip ‘--’ */
+	VSHFT(&opt, 2);
+
+	const struct cli_option *o = nullptr;
+	const char8_t *eq_p = u8chr(opt, '=');
+	struct u8view opt_no_eq = {
+		.p = opt.p,
+		.len = eq_p == nullptr ? opt.len : (size_t)(eq_p - opt.p),
+	};
+
+	for (size_t i = 0; i < nopts; i++) {
+		struct u8view lo = opts[i].longopt;
+		if (lo.p == nullptr || !u8haspfx(lo, opt_no_eq))
+			continue;
+		if (o != nullptr)
+			return error(st, CLI_MSG_INVALID, opt_no_eq);
+		o = opts + i;
+	}
+
+	if (o == nullptr)
+		return error(st, CLI_MSG_INVALID, opt_no_eq);
+
+	switch (o->argtype) {
+	case CLI_NONE:
+		if (eq_p != nullptr)
+			return error(st, CLI_MSG_TOOMANY, opt);
+		break;
+	case CLI_OPT:
+		if (eq_p == nullptr)
+			st->optarg = (struct u8view){};
+		else {
+			ASSUME(opt.len > opt_no_eq.len);
+			st->optarg = (struct u8view){
+				.p = eq_p + 1,
+				.len = opt.len - opt_no_eq.len + 1,
+			};
+		}
+		break;
+	case CLI_REQ:
+		if (eq_p == nullptr) {
+			if (st->_argv[st->optind] == nullptr)
+				return error(st, CLI_MSG_MISSING, opt);
+			st->optarg.p = st->_argv[st->optind++];
+			st->optarg.len = strlen(st->optarg.p);
+		} else {
+			ASSUME(opt.len > opt_no_eq.len);
+			st->optarg = (struct u8view){
+				.p = eq_p + 1,
+				.len = opt.len - opt_no_eq.len + 1,
+			};
+		}
+		break;
+	}
+
+	return o->shortopt;
+}
+
+rune
+shortopt(struct optparser *st, const struct cli_option *opts, size_t nopts)
+{
+	rune ch;
+	const char *opt = st->_argv[st->optind];
+	st->_subopt += u8tor(&ch, opt + st->_subopt + 1);
+	if (ch == '\0') {
+		st->_subopt = 0;
+		st->optind++;
+		return optparse(st, opts, nopts);
+	}
+	for (size_t i = 0; i < nopts; i++) {
+		if (opts[i].shortopt != ch)
+			continue;
+		if (opts[i].argtype == CLI_NONE)
+			goto out;
+		if (opt[st->_subopt + 1] != '\0') {
+			st->optarg.p = opt + st->_subopt + 1;
+			st->optarg.len = strlen(st->optarg.p);
+			st->_subopt = 0;
+			st->optind++;
+			goto out;
+		}
+		if (opts[i].argtype == CLI_OPT) {
+			st->optarg = (struct u8view){};
+			goto out;
+		}
+		if (st->_argv[st->optind + 1] == nullptr) {
+			st->optarg = (struct u8view){};
+			return error(st, CLI_MSG_MISSING, ch);
+		}
+		st->optarg.p = st->_argv[st->optind + 1];
+		st->optarg.len = strlen(st->optarg.p);
+		st->optind += 2;
+		goto out;
+	}
+	return error(st, CLI_MSG_INVALID, ch);
+out:
+	return ch;
+}
+
+rune
+error_s(struct optparser *st, const char *msg, struct u8view s)
+{
+	snprintf(st->errmsg, sizeof(st->errmsg), u8"%s — ‘%.*s’", msg,
+	         SV_PRI_ARGS(s));
+	return -1;
+}
+
+rune
+error_r(struct optparser *st, const char *msg, rune ch)
+{
+	char buf[U8_LEN_MAX + 1] = {};
+	snprintf(st->errmsg, sizeof(st->errmsg), u8"%s — ‘%.*s’", msg,
+	         rtou8(buf, sizeof(buf), ch), buf);
+	return -1;
+}