yaml

The yaml package provides a pure-Kiwi YAML 1.2 parser and serializer.

Supported features: - Block mappings and sequences (any indentation) - Flow collections: {} and [] - Scalars: null, boolean, integer, float, plain and quoted strings - Single- and double-quoted strings with escape sequences - Block scalars: | (literal) and > (folded) - Inline comments - Anchors (&name) and aliases (*name) - Document markers (--- and ...) - Multi-document streams via parse_all() - Serialization via stringify()

---

Package Functions

parse(input)

Parses a YAML string and returns the first document as a Kiwi value.

Parameters

Type	Name	Description
string	input	The YAML-formatted string to parse.

Returns

Type	Description
any	A Kiwi value: hashmap, list, string, integer, float, boolean, or null.

Example

doc = yaml::parse("name: Kiwi\nversion: 2\nactive: true")
println doc["name"]    # Kiwi
println doc["version"] # 2
println doc["active"]  # true

---

parse_file(file_path)

Parses a YAML file and returns the first document.

Parameters

Type	Name	Description
string	file_path	Path to the YAML file.

Returns

Type	Description
any	The parsed document.

Throws

string — if the file does not exist.

Example

doc = yaml::parse_file("/etc/myapp/config.yaml")
println doc["database"]["host"]

---

parse_all(input)

Parses a YAML string containing multiple ----separated documents and returns all of them as a list.

Parameters

Type	Name	Description
string	input	A YAML string with one or more documents.

Returns

Type	Description
list	One parsed document per --- section.

Example

src = "---\nname: first\n---\nname: second"
docs = yaml::parse_all(src)
println docs.size()       # 2
println docs[0]["name"]   # first
println docs[1]["name"]   # second

---

stringify(value)

Serializes a Kiwi value to a YAML-formatted string.

Parameters

Type	Name	Description
any	value	The value to serialize (hashmap, list, scalar, or null).

Returns

Type	Description
string	YAML-formatted string.

Example

data = {name: "Alice", scores: [95, 87, 100], active: true}
println yaml::stringify(data)
# name: Alice
# scores:
#   - 95
#   - 87
#   - 100
# active: true

---

Examples

Nested mapping

src = "
server:
  host: localhost
  port: 8080
  tls: false
"
cfg = yaml::parse(src)
host = cfg["server"]["host"]
port = cfg["server"]["port"]
println "${host}:${port}"  # localhost:8080

Sequence of mappings

src = "
- name: Alice
  age: 30
- name: Bob
  age: 25
"
people = yaml::parse(src)
for p in people do
  n = p["name"]
  a = p["age"]
  println "${n} is ${a}"
end
# Alice is 30
# Bob is 25

Anchors and aliases

src = "
defaults: &defaults
  timeout: 30
  retries: 3

production:
  <<: *defaults
  host: prod.example.com
"
doc = yaml::parse(src)
println doc["defaults"]["timeout"]  # 30

Round-trip (parse → stringify → parse)

original = {project: "Kiwi", version: 2, tags: ["scripting", "aot"]}
serialized = yaml::stringify(original)
restored = yaml::parse(serialized)
tags = restored["tags"]
println tags[0]  # scripting

Scalar type coercion

YAML scalars are automatically coerced to Kiwi types:

YAML literal	Kiwi type	Value
42	integer	42
3.14	float	3.14
true / True / TRUE	boolean	true
false / False / FALSE	boolean	false
null / ~ / Null	null	null
"hello"	string	"hello"