dc

commit 82e950c3bfb9b1a1b95b14ec775c534a68eac0f7
parent cbb5cc555b6dcaed9f5740c33ff3d309721dfd18
Author: Byron Torres <b@torresjrjr.com>
Date:   Tue, 23 Nov 2021 19:02:08 +0000

scan decimal points, ignore blanks, add more ops

Full floating point numbers like 3.14 are scanable.
All blank characters like spaces, tabs and newlines are ignored.
Added multiplication '*', division '/', modulus '%', quit 'q'.

Diffstat:
M
dc.ha
 | 
38
+++++++++++++++++++++++++++++++++++++-

1 file changed, 37 insertions(+), 1 deletion(-)
diff --git a/dc.ha b/dc.ha
@@ -4,6 +4,7 @@ use encoding::utf8;
 use fmt;
 use getopt;
 use io;
+use math;
 use os;
 use strconv;
 use strings;
@@ -46,6 +47,10 @@ export fn main() void = {
 			yield r;
 		};
 
+		if (!ascii::isgraph(r)) {
+			continue;
+		};
+
 		if (ascii::isdigit(r)) {
 			bufio::unreadrune(os::stdin, r);
 			const el = scan_number();
@@ -70,6 +75,30 @@ export fn main() void = {
 			const a = pop();
 			const b = pop();
 			push(a - b);
+		case '*' =>
+			if (len(stack) < 2) {
+				fmt::errorln("dc: stack has too few elements")?;
+				continue;
+			};
+			const a = pop();
+			const b = pop();
+			push(a * b);
+		case '/' =>
+			if (len(stack) < 2) {
+				fmt::errorln("dc: stack has too few elements")?;
+				continue;
+			};
+			const a = pop();
+			const b = pop();
+			push(a / b);
+		case '%' =>
+			if (len(stack) < 2) {
+				fmt::errorln("dc: stack has too few elements")?;
+				continue;
+			};
+			const a = pop();
+			const b = pop();
+			push(math::modf64(a, b));
 		case 'p' =>
 			if (len(stack) == 0) {
 				fmt::errorln("dc: stack has no elements")?;
@@ -77,7 +106,10 @@ export fn main() void = {
 			};
 			const el = peek();
 			fmt::println(el)?;
+		case 'q' =>
+			os::exit(0);
 		case =>
+			fmt::errorfln("dc: unimplemented '{}'", r)?;
 			continue;
 		};
 	};
@@ -91,6 +123,7 @@ export fn main() void = {
 fn scan_number() f64 = {
 	let num: []u8 = [];
 	defer free(num);
+	let seen_decimal = false;
 	for (true) {
 		const r = match (bufio::scanrune(os::stdin)) {
 		case utf8::invalid =>
@@ -103,8 +136,11 @@ fn scan_number() f64 = {
 			yield r;
 		};
 
-		if (ascii::isdigit(r)) {
+		if (ascii::isdigit(r) || (!seen_decimal && r == '.')) {
 			append(num, r: u32: u8);
+			if (r == '.') {
+				seen_decimal = true;
+			};
 		} else {
 			bufio::unreadrune(os::stdin, r);
 			match (strconv::stof64(strings::fromutf8(num))) {