Debugging and Inspection

Structure Summary

Inspect a Field Type

Inspection starts by checking what kind of value a record field contains.

Program

Play the script to choose a field and inspect its simple type label.

structure_summary.R 
item_index <- 
record <- list(count = 3, label = "ready", active = TRUE)
field <- names(record)[item_index]
kind <- class(record[[field]])[1]
label <- paste(field, kind, sep = ":")
cat(label, "\n", sep = "")

item_index <- 
record <- list(count = 3, label = "ready", active = TRUE)
field <- names(record)[item_index]
kind <- class(record[[field]])[1]
label <- paste(field, kind, sep = ":")
cat(label, "\n", sep = "")

item_index <- 
record <- list(count = 3, label = "ready", active = TRUE)
field <- names(record)[item_index]
kind <- class(record[[field]])[1]
label <- paste(field, kind, sep = ":")
cat(label, "\n", sep = "")
record A small named list gives the inspection target.
field name `names(record)[item_index]` chooses which field to inspect.
type label `class(record[[field]])[1]` reports a compact type name.