Commit `f398ac3ee4`

Isaac Freund <ifreund@ifreund.xyz>
2021-06-26 15:21:27
std/fmt: add fmtDurationSigned
When working with durations it often makes sense to use signed integers and allow negative durations, and there is currently no nice way to format these in std.fmt. This patch adds a simple wrapper for the existing fmtDurtion to fit this need.
master
1 parent ef56e42
Changed files (1)
lib
std
fmt.zig
@@ -1461,6 +1461,87 @@ test "fmtDuration" {
     }
 }
 
+fn formatDurationSigned(ns: i64, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {
+    if (ns < 0) {
+        try writer.writeByte('-');
+        try formatDuration(@intCast(u64, -ns), fmt, options, writer);
+    } else {
+        try formatDuration(@intCast(u64, ns), fmt, options, writer);
+    }
+}
+
+/// Return a Formatter for number of nanoseconds according to its signed magnitude:
+/// [#y][#w][#d][#h][#m]#[.###][n|u|m]s
+pub fn fmtDurationSigned(ns: i64) Formatter(formatDurationSigned) {
+    return .{ .data = ns };
+}
+
+test "fmtDurationSigned" {
+    var buf: [24]u8 = undefined;
+    inline for (.{
+        .{ .s = "0ns", .d = 0 },
+        .{ .s = "1ns", .d = 1 },
+        .{ .s = "-1ns", .d = -(1) },
+        .{ .s = "999ns", .d = std.time.ns_per_us - 1 },
+        .{ .s = "-999ns", .d = -(std.time.ns_per_us - 1) },
+        .{ .s = "1us", .d = std.time.ns_per_us },
+        .{ .s = "-1us", .d = -(std.time.ns_per_us) },
+        .{ .s = "1.45us", .d = 1450 },
+        .{ .s = "-1.45us", .d = -(1450) },
+        .{ .s = "1.5us", .d = 3 * std.time.ns_per_us / 2 },
+        .{ .s = "-1.5us", .d = -(3 * std.time.ns_per_us / 2) },
+        .{ .s = "14.5us", .d = 14500 },
+        .{ .s = "-14.5us", .d = -(14500) },
+        .{ .s = "145us", .d = 145000 },
+        .{ .s = "-145us", .d = -(145000) },
+        .{ .s = "999.999us", .d = std.time.ns_per_ms - 1 },
+        .{ .s = "-999.999us", .d = -(std.time.ns_per_ms - 1) },
+        .{ .s = "1ms", .d = std.time.ns_per_ms + 1 },
+        .{ .s = "-1ms", .d = -(std.time.ns_per_ms + 1) },
+        .{ .s = "1.5ms", .d = 3 * std.time.ns_per_ms / 2 },
+        .{ .s = "-1.5ms", .d = -(3 * std.time.ns_per_ms / 2) },
+        .{ .s = "1.11ms", .d = 1110000 },
+        .{ .s = "-1.11ms", .d = -(1110000) },
+        .{ .s = "1.111ms", .d = 1111000 },
+        .{ .s = "-1.111ms", .d = -(1111000) },
+        .{ .s = "1.111ms", .d = 1111100 },
+        .{ .s = "-1.111ms", .d = -(1111100) },
+        .{ .s = "999.999ms", .d = std.time.ns_per_s - 1 },
+        .{ .s = "-999.999ms", .d = -(std.time.ns_per_s - 1) },
+        .{ .s = "1s", .d = std.time.ns_per_s },
+        .{ .s = "-1s", .d = -(std.time.ns_per_s) },
+        .{ .s = "59.999s", .d = std.time.ns_per_min - 1 },
+        .{ .s = "-59.999s", .d = -(std.time.ns_per_min - 1) },
+        .{ .s = "1m", .d = std.time.ns_per_min },
+        .{ .s = "-1m", .d = -(std.time.ns_per_min) },
+        .{ .s = "1h", .d = std.time.ns_per_hour },
+        .{ .s = "-1h", .d = -(std.time.ns_per_hour) },
+        .{ .s = "1d", .d = std.time.ns_per_day },
+        .{ .s = "-1d", .d = -(std.time.ns_per_day) },
+        .{ .s = "1w", .d = std.time.ns_per_week },
+        .{ .s = "-1w", .d = -(std.time.ns_per_week) },
+        .{ .s = "1y", .d = 365 * std.time.ns_per_day },
+        .{ .s = "-1y", .d = -(365 * std.time.ns_per_day) },
+        .{ .s = "1y52w23h59m59.999s", .d = 730 * std.time.ns_per_day - 1 }, // 365d = 52w1d
+        .{ .s = "-1y52w23h59m59.999s", .d = -(730 * std.time.ns_per_day - 1) }, // 365d = 52w1d
+        .{ .s = "1y1h1.001s", .d = 365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_s + std.time.ns_per_ms },
+        .{ .s = "-1y1h1.001s", .d = -(365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_s + std.time.ns_per_ms) },
+        .{ .s = "1y1h1s", .d = 365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_s + 999 * std.time.ns_per_us },
+        .{ .s = "-1y1h1s", .d = -(365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_s + 999 * std.time.ns_per_us) },
+        .{ .s = "1y1h999.999us", .d = 365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_ms - 1 },
+        .{ .s = "-1y1h999.999us", .d = -(365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_ms - 1) },
+        .{ .s = "1y1h1ms", .d = 365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_ms },
+        .{ .s = "-1y1h1ms", .d = -(365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_ms) },
+        .{ .s = "1y1h1ms", .d = 365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_ms + 1 },
+        .{ .s = "-1y1h1ms", .d = -(365 * std.time.ns_per_day + std.time.ns_per_hour + std.time.ns_per_ms + 1) },
+        .{ .s = "1y1m999ns", .d = 365 * std.time.ns_per_day + std.time.ns_per_min + 999 },
+        .{ .s = "-1y1m999ns", .d = -(365 * std.time.ns_per_day + std.time.ns_per_min + 999) },
+    }) |tc| {
+        const slice = try bufPrint(&buf, "{}", .{fmtDurationSigned(tc.d)});
+        try std.testing.expectEqualStrings(tc.s, slice);
+    }
+}
+
 pub const ParseIntError = error{
     /// The result cannot fit in the type specified
     Overflow,
Commit f398ac3ee4

Commit `f398ac3ee4`
