dc

commit 9af0cd2a34a261e50b40439abed2d6abefe8f726
parent ae7c43183148c8699e9357076c5d02ef6db4ef2b
Author: Byron Torres <b@torresjrjr.com>
Date:   Wed, 24 Nov 2021 17:54:24 +0000

handle files

Diffstat:
M
dc.ha
 | 
61
+++++++++++++++++++++++++++++++++++++++++--------------------

1 file changed, 41 insertions(+), 20 deletions(-)
diff --git a/dc.ha b/dc.ha
@@ -2,6 +2,7 @@ use ascii;
 use bufio;
 use encoding::utf8;
 use fmt;
+use fs;
 use getopt;
 use io;
 use math;
@@ -14,29 +15,41 @@ let S: []f64 = [];
 export fn main() void = {
 	const help: [_]getopt::help = [
 		"desk calculator",
-		"[file]",
+		"[file ...]",
 	];
 	const cmd = getopt::parse(os::args, help...);
 	defer getopt::finish(&cmd);
 
-	if (len(cmd.args) > 1) {
-		usage_exit(help);
-	};
+	static const buf: [1]u8 = [0...];
 
-	let filename: (str | void) = if (len(cmd.args) == 1)
-		switch (cmd.args[0]) {
+	for (let i = 0z; i < len(cmd.args); i += 1) {
+		const filename = switch (cmd.args[i]) {
 		case "-" =>
 			fmt::fatal("dc: invalid filename '-'");
 		case "" =>
 			fmt::fatal("dc: invalid filename ''");
 		case =>
-			yield cmd.args[0];
-		}
-	else
-		void;
+			yield cmd.args[i];
+		};
+
+		const file = match (os::open(filename)) {
+		case f: io::file =>
+			yield f;
+		case err: fs::error =>
+			fmt::fatal("dc: {} '{}'", fs::strerror(err), filename);
+		};
+		defer io::close(file);
+
+		const in = bufio::buffered(file, buf, []);
+		dc(in);
+	};
+
+	dc(os::stdin);
+};
 
+fn dc(in: io::handle) void = {
 	for (true) {
-		const r = match (bufio::scanrune(os::stdin)) {
+		const r = match (bufio::scanrune(in)) {
 		case utf8::invalid =>
 			fmt::fatal("dc: invalid utf8 input");
 		case io::error =>
@@ -52,13 +65,13 @@ export fn main() void = {
 		};
 
 		if (ascii::isdigit(r)) {
-			bufio::unreadrune(os::stdin, r);
-			push(scan_number());
+			bufio::unreadrune(in, r);
+			push(scan_number(in));
 			continue;
 		};
 
 		if (r == '_') {
-			push(-scan_number());
+			push(-scan_number(in));
 			continue;
 		};
 
@@ -69,13 +82,13 @@ export fn main() void = {
 		// printing
 		case 'p' =>
 			if (len(S) == 0) {
-				fmt::errorln("dc: stack has no elements")?;
+				fmt::errorln("dc: stack empty")?;
 				continue;
 			};
 			fmt::println(peek())?;
 		case 'n' =>
 			if (len(S) == 0) {
-				fmt::errorln("dc: stack has no elements")?;
+				fmt::errorln("dc: stack empty")?;
 				continue;
 			};
 			fmt::println(pop())?;
@@ -87,8 +100,16 @@ export fn main() void = {
 		case 'c' =>
 			clear();
 		case 'd' =>
+			if (len(S) == 0) {
+				fmt::errorln("dc: stack empty")?;
+				continue;
+			};
 			push(peek());
 		case 'r' =>
+			if (len(S) < 2) {
+				fmt::errorln("dc: stack has too few elements")?;
+				continue;
+			};
 			const b = pop();
 			const a = pop();
 			push(b);
@@ -102,7 +123,7 @@ export fn main() void = {
 				const a = S[i];
 				delete(S[i]);
 				append(S, a);
-			} else if (n < 1) {
+			} else if (n < -1) {
 				const l = len(S): int;
 				const n = if (-n < l) -n else l;
 				const i = l - n;
@@ -169,12 +190,12 @@ export fn main() void = {
 	os::exit(1);
 };
 
-fn scan_number() f64 = {
+fn scan_number(in: io::handle) f64 = {
 	let num: []u8 = [];
 	defer free(num);
 	let seen_decimal = false;
 	for (true) {
-		const r = match (bufio::scanrune(os::stdin)) {
+		const r = match (bufio::scanrune(in)) {
 		case utf8::invalid =>
 			fmt::fatal("dc: invalid utf8 input");
 		case io::error =>
@@ -191,7 +212,7 @@ fn scan_number() f64 = {
 				seen_decimal = true;
 			};
 		} else {
-			bufio::unreadrune(os::stdin, r);
+			bufio::unreadrune(in, r);
 			match (strconv::stof64(strings::fromutf8(num))) {
 			case (strconv::invalid | strconv::overflow) =>
 				abort("dc: invalid numerical input");