YAMLFragments

Overview ¶

YAMLFragment is a type of value that is defined directly in YAML (instead of plain Starlark). For example, function val() returns a value of type yamlfragment.

#@ def vals():
key1: val1
key2:
  subkey: val2
#@ end

YAMLFragment may contain:

• YAML document set (array of YAML documents)
• YAML array
• YAML map
• null

Given various contents it wraps, YAMLFragment currently exposes limited ways of accessing its contents directly. Following accessors are available in v0.26.0+.

YAML Document Set ¶

#@ def docs():
---
doc1
---
doc2
---
doc3
#@ end

• access contents of a document at particular index

docs()[1] # returns "doc2"

• loop over each document, setting val to its contents

for val in docs():
  val # ...
end

YAML Array ¶

#@ def vals():
- val1
- val2
#@ end

• access contents of an array item at particular index

vals()[1] # returns "val2"

• loop over each array item, setting val to its contents

for val in vals():
  val # ...
end

YAML Map ¶

#@ def vals():
key1: val1
key2:
  subkey: val2
#@ end

• access contents of a map item with particular key

vals()["key1"] # returns "val1"

• check if map contains particular key

"key1" in vals() # returns True
"key6" in vals() # returns False

• loop over each map item, setting val to its contents

for key in vals():
  val = vals()[key] # ...
end

• convert to a dictionary

dict(**vals()) # returns {"key1": "val1", "key2": yamlfragment({"subkey": "val2"})}