yaml #

Description

yaml provides a pure-V YAML reader and writer for common configuration files. It supports nested mappings, sequences, flow-style collections, block scalars, tree access through yaml.Any, and generic struct encode/decode.

The generic encode/decode path delegates to the main json module so it matches existing JSON field behavior, including @[json: 'name'].

Usage

import yaml

struct Config {
    name    string
    enabled bool
    ports   []int
}

const config_text = '
name: app
enabled: true
ports:
  - 8080
  - 9090
'

fn main() {
    doc := yaml.parse_text(config_text)!
    assert doc.value('ports[1]').int() == 9090

    config := yaml.decode[Config](config_text)!
    assert config.name == 'app'
    assert yaml.encode(config).contains('"name": "app"')
}

File helpers

import yaml

struct Config {
    name string
}

fn main() {
    config := yaml.decode_file[Config]('config.yml')!
    yaml.encode_file('config.out.yml', config)!
}

fn decode[T](yaml_text string) !T

decode decodes YAML text into the target type T. The generic encode/decode path uses the main json module for field parity.

fn decode_file[T](path string) !T

decode_file decodes the YAML file at path into the target type T.

fn encode[T](value T) string

encode encodes the value value into a YAML string. The generic encode/decode path uses the main json module for field parity.

fn encode_file[T](path string, value T) !

encode_file encodes value as YAML and writes it to path.

fn parse_file(path string) !Doc

parse_file parses the YAML file at path.

fn parse_text(text string) !Doc

parse_text parses the YAML document provided in text.

type Any = []Any | Null | bool | f64 | i64 | int | map[string]Any | string | u64

Any is the tree representation used by the YAML module.

fn (a Any) str() string

str returns a display-friendly string form of Any.

fn (a Any) string() string

string returns Any as a string when possible, or a YAML representation otherwise.

fn (a Any) int() int

int returns Any as an int.

fn (a Any) i64() i64

i64 returns Any as an i64.

fn (a Any) u64() u64

u64 returns Any as a u64.

fn (a Any) f64() f64

f64 returns Any as an f64.

fn (a Any) bool() bool

bool returns Any as a bool.

fn (a Any) array() []Any

array returns Any as an array.

fn (a Any) as_map() map[string]Any

as_map returns Any as a map.

fn (a Any) default_to(value Any) Any

default_to returns value when a is Null.

fn (a Any) value(key string) Any

value queries a value from the current node using dotted keys and array indices.

fn (a Any) value_opt(key string) !Any

value_opt queries a value from the current node and returns an error when missing.

fn (a Any) to_json() string

to_json converts Any to JSON.

fn (a Any) to_yaml() string

to_yaml converts Any to YAML.

fn (a []Any) value(key string) Any

value queries a value from the array.

fn (a []Any) as_strings() []string

as_strings returns the contents of the array as []string.

fn (a []Any) to_yaml() string

to_yaml converts a YAML array to YAML text.

fn (m map[string]Any) value(key string) Any

value queries a value from the map.

fn (m map[string]Any) as_strings() map[string]string

as_strings returns the contents of the map as map[string]string.

fn (m map[string]Any) to_yaml() string

to_yaml converts a YAML map to YAML text.

struct Doc {
pub:
	root Any
}

Doc is a parsed YAML document.

fn (d Doc) decode[T]() !T

decode decodes the YAML document into the target type T.

fn (d Doc) to_any() Any

to_any converts the YAML document to yaml.Any.

fn (d Doc) to_json() string

to_json converts the YAML document to JSON.

fn (d Doc) to_yaml() string

to_yaml converts the YAML document back to YAML text.

fn (d Doc) value(key string) Any

value queries a value from the YAML document. key supports dotted keys and array indexing like servers[0].host.

fn (d Doc) value_opt(key string) !Any

value_opt queries a value from the YAML document and returns an error when missing.

struct Null {}

Null is a simple representation of the YAML null value.