YAML Converter

Bidirectional converter for specific YAML files.

Primary motivation is to have a bidirectional converter for Flow123d input files. However, long term plan is to make it an independent tool for bidirectional conversion of custom YAML file formats.

Requirements

ruamel.yaml

Documentation

PathSet syntax

Modification rules (described further on) are applied to the addresses in the given YAML file that match given PathSet pattern. PathSet pattern is an address like:

/key_a/1/key_b

Following constructs can be used:

'*' character - match any key

'#' character - match any index

'**' - match any sub path (can contain both keys and indices)

'KEY!TAG' - match the KEY only if it have tag TAG. Usefull for custom tags or in combination with '*'.

'(A|B|C)' - match A or B or C. Can be used for both keys and tags.

Tail and value patterns

Single path pattern could be composed from one, two or three patterns seprated by the colon :. The first pattern is always the path pattern, the second is the tail pattern, the third is the value pattern. The tail and value patterns are empty by default.

The tail pattern restricts the modification rule only to the addresses that contains the tail pattern as a subpath. E.g. path pattern x(a|b):y for the YAML file

xa:
  y: 2
xb:
  z: 3  

matches only the address xa as it contains subpath y but does not match the path xb.

The value pattern restricts the modification rule only to the addresses that contains a value which matches the value pattern.

YAML predefined tag names

• 'null'
• 'bool'
• 'int'
• 'float'
• 'binary'
• 'timestamp' - YAML recognize time and date in some format
• 'omap' - ordered map, used by default by ruamel YAML instead of 'map' coud be required explicitely
• 'pairs' - ?
• 'set' - is a mapping where all keys have null value
• 'str'
• 'seq'
• 'map'

Change rules

add_key_to_map(paths, key, value)

set_tag_from_key(paths, key, tag)

manual_change(paths, message_forward, message_backward)

copy_value(new_paths, old_paths)

move_value(new_paths, old_paths)

rename_key(paths, old_key, new_key)

rename_tag(paths, old_tag, new_tag):

replace_value(paths, re_forward, re_backward)

change_value(paths, old_val, new_val)

scale_scalar(paths, multiplicator)