This is a special form: the argument must be a variable identifier. It returns a map where the keys are integers and the values are the date in physical times of the successive assignements to the variable. Integer 0 corresponds to the current value, 1 to the previous value, etc. Variable's history has a bounded length that can be specified using a @localor a@global declaration.

See also @tab_history, @map_history and @map_history_rdate.

See also System Related Functions @arch_darwin    @arch_linux    @arch_windows    @compilation    @configuration_arch    @configuration_audiosample    @configuration_debug    @configuration_faust    @configuration_host    @configuration_release    @configuration_target_architecture    @current_load_directory    @directory_read    @exe_child_of    @exe_parent    @history_length    @host_date    @info    @is_fastforward    @is_following_on    @is_paused    @is_playing_on    @is_running    @is_stopped    @max_absolute_path    @max_patch_path    @pwd    @strip_path    @system    @Tracing    @time    @typecheck    @UnTracing    @usage_resident_memory_size    @usage_statistics    @usage_virtual_memory_size    @user_directory