util.human.io: Add parse_duration() method to parse a duration string

Similar logic occurs throughout various modules in the codebase. We might even
want a module:get_option_duration()??

2 files changed, 30 insertions, 0 deletions

diff --git a/spec/util_human_io_spec.lua b/spec/util_human_io_spec.lua
index f1b28883..c143d028 100644
--- a/spec/util_human_io_spec.lua
+++ b/spec/util_human_io_spec.lua
@@ -42,6 +42,24 @@ describe("util.human.io", function ()
 			assert.equal("räksmörgås", human_io.ellipsis("räksmörgås", 10));
 		end);
 	end);
+
+	describe("parse_duration", function ()
+		local function test(expected, duration)
+			assert.equal(expected, human_io.parse_duration(duration));
+		end
+		it("works", function ()
+			test(1, "1s");
+			test(60, "1mi");
+			test(60, "1min");
+			test(60, "1 min");
+			test(60, "1 minute");
+			test(120, "2min");
+			test(86400, "1d");
+			test(2678400, "1m");
+			test(2678400, "1month");
+			test(2678400, "1 month");
+		end);
+	end);
 end);
 
 
diff --git a/util/human/io.lua b/util/human/io.lua
index 8a903d38..c2ed4904 100644
--- a/util/human/io.lua
+++ b/util/human/io.lua
@@ -197,6 +197,17 @@ local function new_table(col_specs, max_width)
 	end, max_width;
 end
 
+local day = 86400;
+local multipliers = {
+	d = day, w = day * 7, m = 31 * day, mo = 31 * day, y = 365.2425 * day;
+	s = 1, mi = 60, h = 3600
+};
+local function parse_duration(duration_string)
+	local n, m = duration_string:lower():match("(%d+)%s*([dwmy]?.?)");
+	if not n then return nil; end
+	return tonumber(n) * ( multipliers[m] or 1 );
+end
+
 return {
 	getchar = getchar;
 	getline = getline;
@@ -210,4 +221,5 @@ return {
 	term_width = term_width;
 	ellipsis = ellipsis;
 	table = new_table;
+	parse_duration = parse_duration;
 };