dc

commit 07efabcc63e26356c5ba94913cd1357aeefd3bbc
parent 82e950c3bfb9b1a1b95b14ec775c534a68eac0f7
Author: Byron Torres <b@torresjrjr.com>
Date:   Tue, 23 Nov 2021 22:49:40 +0000

add negative numbers and stack control commands

Diffstat:
M
dc.ha
 | 
67
+++++++++++++++++++++++++++++++++++++++++++++++++++++--------------

1 file changed, 53 insertions(+), 14 deletions(-)
diff --git a/dc.ha b/dc.ha
@@ -9,7 +9,7 @@ use os;
 use strconv;
 use strings;
 
-let stack: []f64 = [];
+let S: []f64 = [];
 
 export fn main() void = {
 	const help: [_]getopt::help = [
@@ -53,14 +53,18 @@ export fn main() void = {
 
 		if (ascii::isdigit(r)) {
 			bufio::unreadrune(os::stdin, r);
-			const el = scan_number();
-			push(el);
+			push(scan_number());
+			continue;
+		};
+
+		if (r == '_') {
+			push(-scan_number());
 			continue;
 		};
 
 		switch (r) {
 		case '+' =>
-			if (len(stack) < 2) {
+			if (len(S) < 2) {
 				fmt::errorln("dc: stack has too few elements")?;
 				continue;
 			};
@@ -68,7 +72,7 @@ export fn main() void = {
 			const b = pop();
 			push(a + b);
 		case '-' =>
-			if (len(stack) < 2) {
+			if (len(S) < 2) {
 				fmt::errorln("dc: stack has too few elements")?;
 				continue;
 			};
@@ -76,7 +80,7 @@ export fn main() void = {
 			const b = pop();
 			push(a - b);
 		case '*' =>
-			if (len(stack) < 2) {
+			if (len(S) < 2) {
 				fmt::errorln("dc: stack has too few elements")?;
 				continue;
 			};
@@ -84,7 +88,7 @@ export fn main() void = {
 			const b = pop();
 			push(a * b);
 		case '/' =>
-			if (len(stack) < 2) {
+			if (len(S) < 2) {
 				fmt::errorln("dc: stack has too few elements")?;
 				continue;
 			};
@@ -92,7 +96,7 @@ export fn main() void = {
 			const b = pop();
 			push(a / b);
 		case '%' =>
-			if (len(stack) < 2) {
+			if (len(S) < 2) {
 				fmt::errorln("dc: stack has too few elements")?;
 				continue;
 			};
@@ -100,17 +104,46 @@ export fn main() void = {
 			const b = pop();
 			push(math::modf64(a, b));
 		case 'p' =>
-			if (len(stack) == 0) {
+			if (len(S) == 0) {
 				fmt::errorln("dc: stack has no elements")?;
 				continue;
 			};
 			const el = peek();
 			fmt::println(el)?;
+		case 'f' =>
+			for (let i = len(S) - 1; i < len(S); i -= 1) {
+				const el = S[i];
+				fmt::println(el)?;
+			};
+		case 'c' =>
+			clear();
+		case 'd' =>
+			push(peek());
+		case 'r' =>
+			const a = pop();
+			const b = pop();
+			push(a);
+			push(b);
+		case 'R' =>
+			let n = pop(): int;
+			if (n > 1) {
+				const l = len(S): int;
+				const n = if (n < l) n else l;
+				const i = l - n;
+				const a = S[i];
+				delete(S[i]);
+				append(S, a);
+			} else if (n < 1) {
+				const l = len(S): int;
+				const n = if (-n < l) -n else l;
+				const i = l - n;
+				const a = pop();
+				insert(S[i], a);
+			};
 		case 'q' =>
 			os::exit(0);
 		case =>
 			fmt::errorfln("dc: unimplemented '{}'", r)?;
-			continue;
 		};
 	};
 };
@@ -155,15 +188,21 @@ fn scan_number() f64 = {
 };
 
 fn pop() f64 = {
-	const a = stack[len(stack) - 1];
-	delete(stack[len(stack) - 1]);
+	const a = S[len(S) - 1];
+	delete(S[len(S) - 1]);
 	return a;
 };
 
 fn push(el: f64) void = {
-	append(stack, el);
+	append(S, el);
 };
 
 fn peek() f64 = {
-	return stack[len(stack) - 1];
+	return S[len(S) - 1];
+};
+
+fn clear() void = {
+	for (len(S) != 0) {
+		delete(S[len(S) - 1]);
+	};
 };