always use explicit arguments

CLAUDE.md

@@ -26,6 +26,11 @@ License MIT. Docs: <https://ipeagit.github.io/gtfstools/>.
   `MEMORY.md`.
 - **Code style.** Always use the convention `package::function()`. Exceptions
   are functions from ggplot2 and special data.table operators such as `:=`.
+- **Explicit argument names.** Never use positional arguments. Every
+  function call in R names its arguments explicitly, e.g.
+  `get_trip_length(gtfs = gtfs, trip_id = ids, unit = "km")`, never
+  `get_trip_length(gtfs, ids, unit = "km")`. (Values passed through `...`,
+  as in `c()` or `paste0()`, have no argument name to give.)
 
 Conventions are in [`.claude/rules/r-package-conventions.md`](.claude/rules/r-package-conventions.md);
 gates are in [`.claude/rules/quality-gates.md`](.claude/rules/quality-gates.md).

R/build_graph.R

@@ -232,7 +232,7 @@ build_graph <- function(gtfs,
   # 'frequencies' come from its start and end times, which are fixed too
   # (fields of the wrong class are reported later, when they are used)
 
-  gtfs <- fix_overnight_in_call(gtfs, frequencies = TRUE)
+  gtfs <- fix_overnight_in_call(gtfs = gtfs, frequencies = TRUE)
 
   network <- build_service_network(
     gtfs,

R/filter_by_time_of_day.R

@@ -142,7 +142,7 @@ filter_by_time_of_day <- function(gtfs,
   # they are compared with the time of day as they should be. the returned
   # feed keeps them fixed
 
-  gtfs <- fix_overnight_in_call(gtfs, frequencies = TRUE)
+  gtfs <- fix_overnight_in_call(gtfs = gtfs, frequencies = TRUE)
 
   # if the gtfs contains a frequencies table, it's important to keep the
   # stop_times of the trips listed in there intact.

R/fix_gtfs.R

@@ -153,7 +153,7 @@ fix_gtfs <- function(
   # fix times after midnight before the steps that use the times, which skip
   # the spans that go back
 
-  gtfs_fixed <- fix_overnight_times(gtfs_fixed)
+  gtfs_fixed <- fix_overnight_times(gtfs = gtfs_fixed)
 
   # cap max speed. this is done before interpolating, so the interpolated
   # times follow the capped times