Add isIsoLeapYear variable and fix iyl documentation

src/eval/command/formula.rs

@@ -43,6 +43,7 @@ pub enum Var {
     IsWeekday,
     IsWeekend,
     IsLeapYear,
+    IsIsoLeapYear,
 }
 
 impl Var {
@@ -97,6 +98,7 @@ impl Var {
                 b2i(wd.is_weekend())
             }
             Var::IsLeapYear => b2i(util::is_leap_year(date.year())),
+            Var::IsIsoLeapYear => b2i(util::is_iso_leap_year(date.year())),
         })
     }
 }
@@ -162,6 +164,7 @@ impl From<&Spanned<commands::Expr>> for Expr {
                 commands::Var::IsWeekday => Self::Var(Var::IsWeekday),
                 commands::Var::IsWeekend => Self::Var(Var::IsWeekend),
                 commands::Var::IsLeapYear => Self::Var(Var::IsLeapYear),
+                commands::Var::IsIsoLeapYear => Self::Var(Var::IsIsoLeapYear),
             },
             commands::Expr::Paren(i) => i.as_ref().into(),
             commands::Expr::Neg(i) => Self::Neg(conv(i)),

src/eval/util.rs

@@ -19,6 +19,7 @@ pub fn month_length(year: i32, month: u32) -> u32 {
         .day()
 }
 
+// Length of an ISO week year in days.
 pub fn iso_year_length(year: i32) -> u32 {
     if is_iso_leap_year(year) {
         53 * 7

src/files/commands.rs

@@ -145,7 +145,7 @@ pub enum Var {
     DayReverse,
     /// `iy`, ISO 8601 year
     IsoYear,
-    /// `iyl`, length of current ISO 8601 year **in weeks**
+    /// `iyl`, length of current ISO 8601 year in days
     IsoYearLength,
     /// `iw`, ISO 8601 week
     IsoWeek,
@@ -159,6 +159,8 @@ pub enum Var {
     IsWeekend,
     /// `isLeapYear`, whether the current year is a leap year
     IsLeapYear,
+    /// `isIsoLeapYear`, whether the current year is a long year in the ISO week system
+    IsIsoLeapYear,
 }
 
 impl Var {
@@ -197,6 +199,7 @@ impl Var {
             Var::IsWeekday => "isWeekday",
             Var::IsWeekend => "isWeekend",
             Var::IsLeapYear => "isLeapYear",
+            Var::IsIsoLeapYear => "isIsoLeapYear",
         }
     }
 }

src/files/grammar.pest

@@ -48,7 +48,7 @@ delta = {
 boolean = { "true" | "false" }
 variable = {
     "mon" | "tue" | "wed" | "thu" | "fri" | "sat" | "sun"
-    | "isWeekday" | "isWeekend" | "isLeapYear"
+    | "isWeekday" | "isWeekend" | "isLeapYear" | "isIsoLeapYear"
     | "j"
     | "yl" | "yd" | "yD" | "yw" | "yW" | "y"
     | "ml" | "mw" | "mW" | "m"

src/files/parse.rs

@@ -348,6 +348,7 @@ fn parse_variable(p: Pair<'_, Rule>) -> Var {
         "isWeekday" => Var::IsWeekday,
         "isWeekend" => Var::IsWeekend,
         "isLeapYear" => Var::IsLeapYear,
+        "isIsoLeapYear" => Var::IsIsoLeapYear,
         _ => unreachable!(),
     }
 }