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mstore/vendor/go.yaml.in/yaml/v4/yaml.go
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2026-06-16 08:02:19 +02:00

752 lines
25 KiB
Go

// Copyright 2011-2019 Canonical Ltd
// Copyright 2025 The go-yaml Project Contributors
// SPDX-License-Identifier: Apache-2.0
// Package yaml implements YAML support for the Go language.
//
// Source code and other details for the project are available at GitHub:
//
// https://github.com/yaml/go-yaml
//
// This file contains:
// - Version preset functions (WithV2Defaults, WithV3Defaults, WithV4Defaults)
// - Options API (WithIndent, WithKnownFields, etc.)
// - Type and constant re-exports from internal/libyaml
// - Helper functions for struct field handling
// - Load/Dump API (Load, Dump, Loader, Dumper)
// - Classic APIs (Decoder, Encoder, Unmarshal, Marshal)
package yaml
import (
"errors"
"fmt"
"io"
"go.yaml.in/yaml/v4/internal/libyaml"
"go.yaml.in/yaml/v4/plugin/limit"
)
//-----------------------------------------------------------------------------
// Version presets
//-----------------------------------------------------------------------------
// Usage:
// yaml.Dump(&data, yaml.WithV3Defaults())
// yaml.Dump(&data, yaml.WithV3Defaults(), yaml.WithIndent(2), yaml.WithCompactSeqIndent())
// WithV2Defaults returns V2-compatible default options.
func WithV2Defaults() Option {
return Options(
WithIndent(2),
WithCompactSeqIndent(false),
WithLineWidth(80),
WithUnicode(true),
WithUniqueKeys(true),
WithQuotePreference(QuoteLegacy),
WithPlugin(limit.New()),
)
}
// WithV3Defaults returns V3-compatible default options.
func WithV3Defaults() Option {
return Options(
WithIndent(4),
WithCompactSeqIndent(false),
WithLineWidth(80),
WithUnicode(true),
WithUniqueKeys(true),
WithQuotePreference(QuoteLegacy),
WithPlugin(limit.New()),
)
}
// WithV4Defaults returns the current V4 default options.
func WithV4Defaults() Option {
return Options(
WithIndent(2),
WithCompactSeqIndent(true),
WithLineWidth(80),
WithUnicode(true),
WithUniqueKeys(true),
WithQuotePreference(QuoteSingle),
WithPlugin(limit.New()),
)
}
//-----------------------------------------------------------------------------
// Options
//-----------------------------------------------------------------------------
// Option allows configuring YAML loading and dumping operations.
type Option = libyaml.Option
// Option configuration functions
var (
// WithIndent sets the number of spaces to use for indentation when
// dumping YAML content.
//
// Valid values are 2-9. Common choices: 2 (compact), 4 (readable).
WithIndent = libyaml.WithIndent
// WithCompactSeqIndent configures whether the sequence indicator '- ' is
// considered part of the indentation when dumping YAML content.
//
// If compact is true, '- ' is treated as part of the indentation.
// If compact is false, '- ' is not treated as part of the indentation.
// When called without arguments, defaults to true.
WithCompactSeqIndent = libyaml.WithCompactSeqIndent
// WithKnownFields enables or disables strict field checking during YAML
// loading.
//
// When enabled, loading will return an error if the YAML input contains
// fields that do not correspond to any fields in the target struct.
// When called without arguments, defaults to true.
WithKnownFields = libyaml.WithKnownFields
// WithSingleDocument configures the Loader to only process the first
// document in a YAML stream. After the first document is loaded,
// subsequent calls to Load will return [io.EOF].
//
// When called without arguments, defaults to true.
//
// This is useful when you expect exactly one document and want behavior
// similar to Unmarshal.
WithSingleDocument = libyaml.WithSingleDocument
// WithStreamNodes enables returning stream boundary nodes when loading
// YAML.
//
// When enabled, Loader.Load returns an interleaved sequence of
// StreamNode and DocumentNode values:
//
// [StreamNode, DocNode, StreamNode, DocNode, ..., StreamNode]
//
// StreamNodes contain metadata about the stream including:
// - Encoding (UTF-8, UTF-16LE, UTF-16BE)
// - YAML version directive (%YAML)
// - Tag directives (%TAG)
// - Position information (Line, Column)
//
// An empty YAML stream returns a single StreamNode.
// When called without arguments, defaults to true.
//
// The default is false.
WithStreamNodes = libyaml.WithStreamNodes
// WithAllDocuments enables multi-document mode for Load and Dump
// operations.
//
// When used with Load, the target must be a pointer to a slice.
// All documents in the YAML stream will be decoded into the slice.
// Zero documents results in an empty slice (no error).
//
// When used with Dump, the input must be a slice.
// Each element will be encoded as a separate YAML document
// with "---" separators.
//
// When called without arguments, defaults to true.
//
// The default is false (single-document mode).
WithAllDocuments = libyaml.WithAllDocuments
// WithLineWidth sets the preferred line width for YAML output.
//
// When encoding long strings, the encoder will attempt to wrap them at
// this width using literal block style (|). Set to -1 or 0 for unlimited
// width.
//
// The default is 80 characters.
WithLineWidth = libyaml.WithLineWidth
// WithUnicode controls whether non-ASCII characters are allowed in YAML
// output.
//
// When true, non-ASCII characters appear as-is (e.g., "café").
// When false, non-ASCII characters are escaped (e.g., "caf\u00e9").
// When called without arguments, defaults to true.
//
// The default is true.
WithUnicode = libyaml.WithUnicode
// WithUniqueKeys enables or disables duplicate key detection during YAML
// loading.
//
// When enabled, loading will return an error if the YAML input contains
// duplicate keys in any mapping. This is a security feature that prevents
// key override attacks.
// When called without arguments, defaults to true.
//
// The default is true.
WithUniqueKeys = libyaml.WithUniqueKeys
// WithCanonical forces canonical YAML output format.
//
// When enabled, the encoder outputs strictly canonical YAML with explicit
// tags for all values. This produces verbose output primarily useful for
// debugging and YAML spec compliance testing.
// When called without arguments, defaults to true.
//
// The default is false.
WithCanonical = libyaml.WithCanonical
// WithLineBreak sets the line ending style for YAML output.
//
// Available options:
// - LineBreakLN: Unix-style \n (default)
// - LineBreakCR: Old Mac-style \r
// - LineBreakCRLN: Windows-style \r\n
//
// The default is LineBreakLN.
WithLineBreak = libyaml.WithLineBreak
// WithExplicitStart controls whether document start markers (---) are
// always emitted.
//
// When true, every document begins with an explicit "---" marker.
// When false (default), the marker is omitted for the first document.
// When called without arguments, defaults to true.
WithExplicitStart = libyaml.WithExplicitStart
// WithExplicitEnd controls whether document end markers (...) are always
// emitted.
//
// When true, every document ends with an explicit "..." marker.
// When false (default), the marker is omitted.
// When called without arguments, defaults to true.
WithExplicitEnd = libyaml.WithExplicitEnd
// WithFlowSimpleCollections controls whether simple collections use flow
// style.
//
// When true, sequences and mappings containing only scalar values (no
// nested collections) are rendered in flow style if they fit within the
// line width.
// Example: {name: test, count: 42} or [a, b, c]
// When called without arguments, defaults to true.
//
// When false (default), all collections use block style.
WithFlowSimpleCollections = libyaml.WithFlowSimpleCollections
// WithQuotePreference sets the preferred quote style for strings that
// require quoting.
//
// This option only affects strings that require quoting per the YAML spec.
// Plain strings that don't need quoting remain unquoted regardless of this
// setting. Quoting is required for:
// - Strings that look like other YAML types (true, false, null, 123, etc.)
// - Strings with leading/trailing whitespace
// - Strings containing special YAML syntax characters
// - Empty strings in certain contexts
//
// Quote styles:
// - QuoteSingle: Use single quotes (v4 default)
// - QuoteDouble: Use double quotes
// - QuoteLegacy: Legacy v2/v3 behavior (mixed quoting)
WithQuotePreference = libyaml.WithQuotePreference
)
// Options combines multiple options into a single Option.
// This is useful for creating option presets or combining version defaults
// with custom options.
//
// Example:
//
// opts := yaml.Options(yaml.WithV4Defaults(), yaml.WithIndent(3))
// yaml.Dump(&data, opts)
func Options(opts ...Option) Option {
return libyaml.CombineOptions(opts...)
}
// DepthKind represents the type of nesting (flow or block).
type DepthKind = libyaml.DepthKind
// DepthKind constants for nesting depth checks.
const (
DepthKindFlow = libyaml.DepthKindFlow
DepthKindBlock = libyaml.DepthKindBlock
)
// DepthContext holds context about a nesting depth check.
type DepthContext = libyaml.DepthContext
// WithPlugin registers one or more plugins for YAML processing.
//
// Plugins extend the YAML library with custom processing logic.
// Each plugin implements one or more plugin interfaces.
// Currently supported plugin types:
// - LimitPlugin: Controls depth and alias expansion limits
//
// Example:
//
// import "go.yaml.in/yaml/v4/plugin/limit"
// loader := yaml.NewLoader(data, yaml.WithPlugin(limit.New(limit.AliasNone())))
//
// Plugins use public types and can be implemented by external packages.
func WithPlugin(plugins ...any) Option {
return func(o *libyaml.Options) error {
for _, p := range plugins {
registered := false
if lp, ok := p.(LimitPlugin); ok {
o.DepthCheck = lp.CheckDepth
o.AliasCheck = lp.CheckAlias
registered = true
}
// Future plugin types add cases here (non-exclusive if)
if !registered {
return fmt.Errorf("yaml: unsupported plugin type: %T", p)
}
}
return nil
}
}
// OptsYAML parses a YAML string containing option settings and returns
// an Option that can be combined with other options using Options().
//
// The YAML string can specify any of these fields:
// - indent (int)
// - compact-seq-indent (bool)
// - line-width (int)
// - unicode (bool)
// - canonical (bool)
// - line-break (string: ln, cr, crln)
// - explicit-start (bool)
// - explicit-end (bool)
// - flow-simple-coll (bool)
// - known-fields (bool)
// - single-document (bool)
// - unique-keys (bool)
// - plugin (map of plugin name to config)
//
// The plugin field configures plugins by name. Each key is a plugin
// name and the value is its configuration map (or null for defaults).
// Currently supported: "limit" with keys "depth" and "alias" (int
// or null to disable).
//
// Only fields specified in the YAML will override other options when
// combined. Unspecified fields won't affect other options.
//
// Example:
//
// opts, err := yaml.OptsYAML(`
// indent: 3
// known-fields: true
// plugin:
// limit:
// depth: 50
// `)
// yaml.Dump(&data, yaml.Options(V4, opts))
func OptsYAML(yamlStr string) (Option, error) {
var cfg struct {
Indent *int `yaml:"indent"`
CompactSeqIndent *bool `yaml:"compact-seq-indent"`
LineWidth *int `yaml:"line-width"`
Unicode *bool `yaml:"unicode"`
Canonical *bool `yaml:"canonical"`
LineBreak *string `yaml:"line-break"`
ExplicitStart *bool `yaml:"explicit-start"`
ExplicitEnd *bool `yaml:"explicit-end"`
FlowSimpleCollections *bool `yaml:"flow-simple-coll"`
KnownFields *bool `yaml:"known-fields"`
SingleDocument *bool `yaml:"single-document"`
UniqueKeys *bool `yaml:"unique-keys"`
Plugin map[string]any `yaml:"plugin"`
}
if err := Load([]byte(yamlStr), &cfg, WithKnownFields()); err != nil {
return nil, err
}
// Build options only for fields that were set
var optList []Option
if cfg.Indent != nil {
optList = append(optList, WithIndent(*cfg.Indent))
}
if cfg.CompactSeqIndent != nil {
optList = append(optList, WithCompactSeqIndent(*cfg.CompactSeqIndent))
}
if cfg.LineWidth != nil {
optList = append(optList, WithLineWidth(*cfg.LineWidth))
}
if cfg.Unicode != nil {
optList = append(optList, WithUnicode(*cfg.Unicode))
}
if cfg.ExplicitStart != nil {
optList = append(optList, WithExplicitStart(*cfg.ExplicitStart))
}
if cfg.ExplicitEnd != nil {
optList = append(optList, WithExplicitEnd(*cfg.ExplicitEnd))
}
if cfg.FlowSimpleCollections != nil {
optList = append(optList, WithFlowSimpleCollections(*cfg.FlowSimpleCollections))
}
if cfg.KnownFields != nil {
optList = append(optList, WithKnownFields(*cfg.KnownFields))
}
if cfg.SingleDocument != nil && *cfg.SingleDocument {
optList = append(optList, WithSingleDocument())
}
if cfg.UniqueKeys != nil {
optList = append(optList, WithUniqueKeys(*cfg.UniqueKeys))
}
if cfg.Canonical != nil {
optList = append(optList, WithCanonical(*cfg.Canonical))
}
if cfg.LineBreak != nil {
switch *cfg.LineBreak {
case "ln":
optList = append(optList, WithLineBreak(LineBreakLN))
case "cr":
optList = append(optList, WithLineBreak(LineBreakCR))
case "crln":
optList = append(optList, WithLineBreak(LineBreakCRLN))
default:
return nil, errors.New("yaml: invalid line-break value (use ln, cr, or crln)")
}
}
for name, val := range cfg.Plugin {
switch name {
case "limit":
var cfgMap map[string]any
switch v := val.(type) {
case nil:
cfgMap = map[string]any{}
case map[string]any:
cfgMap = v
default:
return nil, fmt.Errorf("yaml: plugin %q value must be a mapping or null", name)
}
p, err := limit.NewFromYAML(cfgMap)
if err != nil {
return nil, err
}
optList = append(optList, WithPlugin(p))
default:
return nil, fmt.Errorf("yaml: unknown plugin %q", name)
}
}
return Options(optList...), nil
}
//-----------------------------------------------------------------------------
// Type and constant re-exports
//-----------------------------------------------------------------------------
// Re-export stream-related types
type (
Stream = libyaml.Stream
VersionDirective = libyaml.StreamVersionDirective
// TagDirective represents a YAML %TAG directive for stream nodes.
TagDirective = libyaml.StreamTagDirective
// Encoding represents the character encoding of a YAML stream.
Encoding = libyaml.Encoding
)
// Encoding constants for YAML stream encoding
const (
// EncodingAny lets the parser choose the encoding.
EncodingAny = libyaml.ANY_ENCODING
// EncodingUTF8 is the default UTF-8 encoding.
EncodingUTF8 = libyaml.UTF8_ENCODING
// EncodingUTF16LE is UTF-16-LE encoding with BOM.
EncodingUTF16LE = libyaml.UTF16LE_ENCODING
// EncodingUTF16BE is UTF-16-BE encoding with BOM.
EncodingUTF16BE = libyaml.UTF16BE_ENCODING
)
// Stage identifies the processing stage where an error occurred during YAML
// loading or dumping.
type Stage = libyaml.Stage
// Stage constants for YAML processing pipeline.
const (
// Load stages
ReaderStage = libyaml.ReaderStage // Input reading and encoding
ScannerStage = libyaml.ScannerStage // Tokenization
ParserStage = libyaml.ParserStage // Event stream parsing
ComposerStage = libyaml.ComposerStage // Node tree construction
ResolverStage = libyaml.ResolverStage // Tag resolution
ConstructorStage = libyaml.ConstructorStage // Go value construction
// Dump stages
RepresenterStage = libyaml.RepresenterStage // Go value to Node tree
SerializerStage = libyaml.SerializerStage // Node tree to events
EmitterStage = libyaml.EmitterStage // Events to YAML bytes
WriterStage = libyaml.WriterStage // Output writing
)
// Mark represents a position in the YAML document.
type Mark = libyaml.Mark
// Error types for YAML loading and dumping
type (
// LoadError represents an error encountered while decoding a YAML document.
//
// It contains details about the location in the document where the error
// occurred, as well as the processing stage that generated it.
LoadError = libyaml.LoadError
// LoadErrors is returned when one or more fields cannot be properly decoded.
//
// It contains multiple *[LoadError] instances with details about each error.
LoadErrors = libyaml.LoadErrors
// DumpError represents an error that occurred while dumping a YAML document.
//
// It identifies the processing stage where the error occurred and provides
// an optional underlying cause via Unwrap.
DumpError = libyaml.DumpError
// TypeError is a legacy error type retained for compatibility.
//
// Deprecated: Use [LoadErrors] instead.
//
//nolint:staticcheck // we are using deprecated TypeError for compatibility
TypeError = libyaml.TypeError
)
// NewLoadError creates a LoadError with an underlying cause error.
// The cause is accessible via Unwrap for use with [errors.Is] and [errors.As].
var NewLoadError = libyaml.NewLoadError
// NewDumpError creates a DumpError with an underlying cause error.
// The cause is accessible via Unwrap for use with [errors.Is] and [errors.As].
var NewDumpError = libyaml.NewDumpError
// LineBreak represents the line ending style for YAML output.
type LineBreak = libyaml.LineBreak
// Line break constants for different platforms.
const (
LineBreakLN = libyaml.LN_BREAK // Unix-style \n (default)
LineBreakCR = libyaml.CR_BREAK // Old Mac-style \r
LineBreakCRLN = libyaml.CRLN_BREAK // Windows-style \r\n
)
// QuoteStyle represents the quote style to use when quoting is required.
type QuoteStyle = libyaml.QuoteStyle
// Quote style constants for required quoting.
const (
QuoteSingle = libyaml.QuoteSingle // Prefer single quotes (v4 default)
QuoteDouble = libyaml.QuoteDouble // Prefer double quotes
QuoteLegacy = libyaml.QuoteLegacy // Legacy v2/v3 behavior
)
//-----------------------------------------------------------------------------
// Load/Dump API
//-----------------------------------------------------------------------------
// Advanced streaming API types
type (
// Loader reads and loads YAML values from an input stream with
// configurable options.
Loader = libyaml.Loader
// Dumper writes YAML values to an output stream with configurable options.
Dumper = libyaml.Dumper
)
// NewLoader returns a new Loader that reads from r with the given options.
func NewLoader(r io.Reader, opts ...Option) (*Loader, error) {
return libyaml.NewLoader(r, opts...)
}
// NewDumper returns a new Dumper that writes to w with the given options.
func NewDumper(w io.Writer, opts ...Option) (*Dumper, error) {
return libyaml.NewDumper(w, opts...)
}
// Load loads YAML document(s) with the given options.
func Load(in []byte, out any, opts ...Option) error {
return libyaml.Load(in, out, opts...)
}
// Dump encodes a value to YAML with the given options.
func Dump(in any, opts ...Option) (out []byte, err error) {
return libyaml.Dump(in, opts...)
}
//-----------------------------------------------------------------------------
// Classic APIs
//-----------------------------------------------------------------------------
// A Decoder reads and decodes YAML values from an input stream.
type Decoder struct {
loader *Loader
}
// NewDecoder returns a new decoder that reads from r.
//
// The decoder introduces its own buffering and may read
// data from r beyond the YAML values requested.
func NewDecoder(r io.Reader) *Decoder {
// NewLoader won't return error with WithV3Defaults() and withFromLegacy
loader, _ := NewLoader(r, WithV3Defaults(), withFromLegacy())
return &Decoder{loader: loader}
}
// KnownFields ensures that the keys in decoded mappings to
// exist as fields in the struct being decoded into.
func (dec *Decoder) KnownFields(enable bool) {
dec.loader.SetKnownFields(enable)
}
// Decode reads the next YAML-encoded value from its input
// and stores it in the value pointed to by v.
//
// See the documentation for Unmarshal for details about the
// conversion of YAML into a Go value.
func (dec *Decoder) Decode(v any) error {
return dec.loader.Load(v)
}
// An Encoder writes YAML values to an output stream.
type Encoder struct {
dumper *Dumper
}
// NewEncoder returns a new encoder that writes to w.
// The Encoder should be closed after use to flush all data
// to w.
func NewEncoder(w io.Writer) *Encoder {
// NewDumper won't return an error when using WithV3Defaults()
dumper, _ := NewDumper(w, WithV3Defaults())
return &Encoder{dumper: dumper}
}
// Encode writes the YAML encoding of v to the stream.
// If multiple items are encoded to the stream, the
// second and subsequent document will be preceded
// with a "---" document separator, but the first will not.
//
// See the documentation for Marshal for details about the conversion of Go
// values to YAML.
func (e *Encoder) Encode(v any) error {
return e.dumper.Dump(v)
}
// SetIndent changes the used indentation used when encoding.
func (e *Encoder) SetIndent(spaces int) {
e.dumper.SetIndent(spaces)
}
// CompactSeqIndent makes it so that '- ' is considered part of the indentation.
func (e *Encoder) CompactSeqIndent() {
e.dumper.SetCompactSeqIndent(true)
}
// DefaultSeqIndent makes it so that '- ' is not considered part of the indentation.
func (e *Encoder) DefaultSeqIndent() {
e.dumper.SetCompactSeqIndent(false)
}
// Close closes the encoder by writing any remaining data.
// It does not write a stream terminating string "...".
func (e *Encoder) Close() error {
return e.dumper.Close()
}
// Unmarshal decodes the first document found within the in byte slice
// and assigns decoded values into the out value.
//
// Maps and pointers (to a struct, string, int, etc) are accepted as out
// values. If an internal pointer within a struct is not initialized,
// the yaml package will initialize it if necessary for unmarshalling
// the provided data. The out parameter must not be nil.
//
// The type of the decoded values should be compatible with the respective
// values in out. If one or more values cannot be decoded due to a type
// mismatches, decoding continues partially until the end of the YAML
// content, and a *yaml.LoadErrors is returned with details for all
// missed values.
//
// Struct fields are only unmarshalled if they are exported (have an
// upper case first letter), and are unmarshalled using the field name
// lowercased as the default key. Custom keys may be defined via the
// "yaml" name in the field tag: the content preceding the first comma
// is used as the key, and the following comma-separated options are
// used to tweak the marshaling process (see Marshal).
// Conflicting names result in a runtime error.
//
// For example:
//
// type T struct {
// F int `yaml:"a,omitempty"`
// B int
// }
// var t T
// yaml.Construct([]byte("a: 1\nb: 2"), &t)
//
// See the documentation of Marshal for the format of tags and a list of
// supported tag options.
func Unmarshal(in []byte, out any) (err error) {
return Load(in, out, WithV3Defaults(), withFromLegacy())
}
// withFromLegacy is a private option that indicates this call is from
// a legacy API (Unmarshal/Decoder). It enables Unmarshaler interface
// checking and allows trailing content for backward compatibility.
func withFromLegacy() Option {
return func(o *libyaml.Options) error {
o.FromLegacy = true
return nil
}
}
// Marshal serializes the value provided into a YAML document. The structure
// of the generated document will reflect the structure of the value itself.
// Maps and pointers (to struct, string, int, etc) are accepted as the in value.
//
// Struct fields are only marshaled if they are exported (have an upper case
// first letter), and are marshaled using the field name lowercased as the
// default key. Custom keys may be defined via the "yaml" name in the field
// tag: the content preceding the first comma is used as the key, and the
// following comma-separated options are used to tweak the marshaling process.
// Conflicting names result in a runtime error.
//
// The field tag format accepted is:
//
// `(...) yaml:"[<key>][,<flag1>[,<flag2>]]" (...)`
//
// The following flags are currently supported:
//
// omitempty Only include the field if it's not set to the zero
// value for the type or to empty slices or maps.
// Zero valued structs will be omitted if all their public
// fields are zero, unless they implement an IsZero
// method (see the IsZeroer interface type), in which
// case the field will be excluded if IsZero returns true.
//
// flow Marshal using a flow style (useful for structs,
// sequences and maps).
//
// inline Inline the field, which must be a struct or a map,
// causing all of its fields or keys to be processed as if
// they were part of the outer struct. For maps, keys must
// not conflict with the yaml keys of other struct fields.
// See doc/inline-tags.md for detailed examples and use cases.
//
// In addition, if the key is "-", the field is ignored.
//
// For example:
//
// type T struct {
// F int `yaml:"a,omitempty"`
// B int
// }
// yaml.Marshal(&T{B: 2}) // Returns "b: 2\n"
// yaml.Marshal(&T{F: 1}} // Returns "a: 1\nb: 0\n"
func Marshal(in any) (out []byte, err error) {
// Use WithV3Defaults() with unlimited line width to match legacy DefaultOptions
return Dump(in, WithV3Defaults(), WithLineWidth(-1))
}