# This document defines the BNF grammar that will be supported in Taskwarrior
# 2.1.


# Commands (alphabetically)

command_add         ::= "add" ws+ task-elements ;

command_annotate    ::= "annotate" ws+ range ws+ words ;

command_append      ::= "append" ws+ range ws+ words ;

command_burndown    ::= "burndown.monthly" ws+ filter
                      | "burndown.weekly"  ws+ filter
                      | "burndown.daily"   ws+ filter
                      | "burndown.monthly"
                      | "burndown.weekly"
                      | "burndown.daily"
                      ;

command_calendar    ::= "calendar" ws+ "due" ws+ filter
                      | "calendar" ws+ "due"
                      | "calendar" ws+ "y" ws+ filter
                      | "calendar" ws+ "y"
                      | "calendar" ws+ year ws+ filter
                      | "calendar" ws+ year
                      | "calendar" ws+ year ws+ month ws+ filter
                      | "calendar" ws+ year ws+ month
                      | "calendar" ws+ month-name ws+ filter
                      | "calendar" ws+ month-name
                      | "calendar" ws+ filter
                      | "calendar"
                      ;

command_colors      ::= "colors" ws+ "legend"
                      | "colors" ws+ "sample"
                      | "colors"
                      ;

command_config      ::= "config" ws+ word ws+ words
                      | "config" ws+ word
                      ;

command_count       ::= "count" ws+ filter
                      | "count"
                      ;

# TODO en-passant
command_delete      ::= "delete" ws+ range ;

command_denotate    ::= "denotate" ws+ range ws+ pattern ;

command_diagnostics ::= "diagnostics" ;

# TODO en-passant
command_done        ::= "done" ws+ range ;

# TODO en-passant
command_duplicate   ::= "duplicate" ws+ range ;

command_edit        ::= "edit" ws+ range ;

command_ghistory    ::= "ghistory.annual"  ws+ filter
                      | "ghistory.monthly" ws+ filter
                      | "ghistory.weekly"  ws+ filter
                      | "ghistory.daily"   ws+ filter
                      | "ghistory.annual"
                      | "ghistory.monthly"
                      | "ghistory.weekly"
                      | "ghistory.daily"
                      ;

command_help        ::= "help" ;

command_history     ::= "history.annual"  ws+ filter
                      | "history.monthly" ws+ filter
                      | "history.weekly"  ws+ filter
                      | "history.daily"   ws+ filter
                      | "history.annual"
                      | "history.monthly"
                      | "history.weekly"
                      | "history.daily"
                      ;

command_import      ::= "import" ws+ file
                      | "import" ws+ "-"
                      ;

command_info        ::= "info" ws+ range
                      ;

command_log         ::= "log" ws+ task-elements ;

command_merge       ::= "merge" ws+ url ;

command_prepend     ::= "prepend" ws+ range ws+ words ;

command_projects    ::= "projects" ws+ filter
                      | "projects"
                      ;

command_pull        ::= "pull" ws+ url ;

command_push        ::= "push" ws+ url ;

command_shell       ::= "shell" ;

command_show        ::= "show" ws+ pattern
                      | "show"
                      ;

command_start       ::= "start" ws+ range
                      | "start"
                      ;

command_stats       ::= "statistics" ws+ filter
                      | "statistics"
                      ;

command_stop        ::= "stop" ws+ range
                      | "stop"
                      ;

command_summary     ::= "summary" ws+ filter
                      | "summary"
                      ;

command_tags        ::= "tags" ;

command_timesheet   ::= "timesheet" ws+ digit
                      | "timesheet"
                      ;

command_undo        ::= "undo" ;

command_version     ::= "version" ;

# command_report      ::= report ws+ filter ;


# Helper Commands (alphabetically)

helper_query        ::= "query" ws+ filter
                      | "query"
                      ;


# Primitives
range               ::=   ;
id-equivalent       ::= uuid | id ;
id                  ::= digit+ ;
uuid                ::=   ;
attribute           ::=   ;
modifier            ::=   ;

task-elements       ::= task-element+ ;

task-element        ::= attribute ws+
                      | tag ws+
                      | word ws+
                      ;

filter              ::= filter-elements+ ;

filter-elements     ::= range
                      | pattern
                      | filter-attribute ;

filter-attribute    ::= field modifier? ":" value? ;

modifier            ::= ".above"
                      | ".after"
                      | ".any"
                      | ".before"
                      | ".below"
                      | ".contains"
                      | ".endswith"
                      | ".equals"
                      | ".has"
                      | ".hasnt"
                      | ".is"
                      | ".isnt"
                      | ".left"
                      | ".none"
                      | ".not"
                      | ".noword"
                      | ".over"
                      | ".right"
                      | ".startswith"
                      | ".under"
                      | ".word"
                      ;

value               ::=   ;

year                ::= digit digit digit digit ;

month               ::= "1" | "2" | "3" |  "4" |  "5" |  "6"
                      | "7" | "8" | "9" | "10" | "11" | "12"
                      ;

# TODO Case-insensitive
month-name          ::= "january"
                      | "february"
                      | "march"
                      | "april"
                      | "may"
                      | "june"
                      | "july"
                      | "august"
                      | "september"
                      | "october"
                      | "november"
                      | "december"
                      ;

filter-attribute    ::= field "." modifier ":" value
                      | field "." modifier ":"
                      | field ":" value
                      | field ":"
                      ;

tag                 ::= "+" word
                      | "-" word ;

substitution        ::= "/" pattern "/" words "/" "g"? ;

pattern             ::=   ;
url                 ::=   ;
file                ::=   ;
words               ::=   ;
word                ::=   ;


# Fundamentals

digit               ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
ws                  ::= " " | "\t" ;

# End