# 1. we parse metadata tags in transaction and posting comments. Currently,
# - they can be on the same line and/or separate lines
# - they are always printed on separate lines
bin/hledger -f - print
<<<
2010/01/01  ; txntag1: txn val 1
  ; txntag2: txn val 2
  a             1
  ; posting1tag1: posting 1 val 1
  ; posting1tag2: 
  b            -1   ; posting-2-tag-1: posting 2 val 1
  ; posting-2-tag-2:
; non-metadata:
>>>
2010/01/01
    ; txntag1: txn val 1
    ; txntag2: txn val 2
    a             1
    ; posting1tag1: posting 1 val 1
    ; posting1tag2: 
    b            -1
    ; posting-2-tag-1: posting 2 val 1
    ; posting-2-tag-2: 

>>>2
>>>=0

# 2. print (and a few other commands) can filter by tag value
bin/hledger -f - print tag foo=bar
<<<
2010/01/01
  ; foo:bar
  a             1
  b            -1

2010/01/02
  ; foo:baz
  c             1
  d            -1

2010/01/03
    e             1
    f            -1
>>>
2010/01/01
    ; foo: bar
    a             1
    b            -1

>>>2
>>>=0

# # 3. or tag existence ? not yet
# bin/hledger -f - print tag foo
# <<<
# 2010/01/01
#   ; foo:bar
#   a             1
#   b            -1

# 2010/01/02
#   ; foo:baz
#   c             1
#   d            -1

# 2010/01/03
#     e             1
#     f            -1
# >>>
# 2010/01/01
#   ; foo:bar
#     a             1
#     b            -1

# 2010/01/02
#   ; foo:baz
#     c             1
#     d            -1

# >>>2
# >>>=0