dialect

Documentation

Overview

Package dialect provides canonical type-to-language mapping via dialect registries. A dialect maps canonical type names (e.g., "string", "uuid", "datetime") to language-specific spellings (e.g., Go's "string", Postgres's "UUID").

Index

• Variables
• func UserDialectsDir() (string, error)
• type Dialect
• type Registry
  • func LoadDefaults() (*Registry, error)
  • func LoadForTemplate(templateRoot, dialectsDirName string) (*Registry, error)
  • func LoadWithOverrides(userDir, templateDir string) (*Registry, error)
  • func NewRegistry() *Registry
  • func (r *Registry) Get(name string) *Dialect
  • func (r *Registry) Load(data []byte) error
  • func (r *Registry) LoadDir(dir string) error
  • func (r *Registry) LoadFS(fsys fs.FS, dir string) error
  • func (r *Registry) Names() []string
  • func (r *Registry) Resolve(canonicalType, dialectName string) (string, error)

Variables

var (
	// ErrUnknownDialect is returned when resolving a type against a dialect that
	// does not exist in the registry.
	ErrUnknownDialect = errors.New("unknown dialect")

	// ErrUnmappedType is returned when a canonical type has no mapping in the
	// requested dialect.
	ErrUnmappedType = errors.New("unmapped canonical type")
)

Sentinel errors for dialect resolution.

Functions

func UserDialectsDir

func UserDialectsDir() (string, error)

UserDialectsDir returns the user-global dialect directory path. This is <XDG_DATA_HOME>/tag/dialects/ (typically ~/.local/share/tag/dialects/).

Types

type Dialect

type Dialect struct {
	Name        string            `yaml:"name"`
	Description string            `yaml:"description,omitempty"`
	Types       map[string]string `yaml:"types"`
}

Dialect represents a single dialect with its type mappings.

type Registry

type Registry struct {
	// contains filtered or unexported fields
}

Registry holds a collection of named dialects and resolves canonical types to dialect-specific types.

func LoadDefaults

func LoadDefaults() (*Registry, error)

LoadDefaults creates a registry populated with only the built-in dialects.

func LoadForTemplate

func LoadForTemplate(templateRoot, dialectsDirName string) (*Registry, error)

LoadForTemplate loads dialects using three-tier resolution for a given template directory: built-in → user-global → template-local (_dialects/). The dialectsDir constant must be passed in to avoid a dependency on internal/types from this leaf package.

func LoadWithOverrides

func LoadWithOverrides(userDir, templateDir string) (*Registry, error)

LoadWithOverrides creates a registry using three-tier loading:

1. Built-in dialects (embedded YAML files)
2. User-global dialects from userDir (if non-empty and directory exists)
3. Template-local dialects from templateDir (if non-empty and directory exists)

Later tiers override individual type mappings via deep merge. Empty directory paths are silently skipped.

func NewRegistry

func NewRegistry() *Registry

NewRegistry creates an empty dialect registry.

func (*Registry) Get

func (r *Registry) Get(name string) *Dialect

Get returns the dialect with the given name, or nil if it does not exist. The returned Dialect must not be modified by callers.

func (*Registry) Load

func (r *Registry) Load(data []byte) error

Load parses a single YAML dialect definition and merges it into the registry. If a dialect with the same name already exists, the type mappings are deep-merged (individual type keys from the new definition override existing ones).

func (*Registry) LoadDir

func (r *Registry) LoadDir(dir string) error

LoadDir loads all *.yaml files from a directory on disk into the registry. Files are loaded in lexical order for deterministic results. Returns nil if the directory does not exist.

func (*Registry) LoadFS

func (r *Registry) LoadFS(fsys fs.FS, dir string) error

LoadFS loads all *.yaml files from a directory within an fs.FS into the registry. Files are loaded in lexical order for deterministic results. Uses forward-slash path joining as required by the fs.FS interface.

func (*Registry) Names

func (r *Registry) Names() []string

Names returns the sorted names of all dialects in the registry.

func (*Registry) Resolve

func (r *Registry) Resolve(canonicalType, dialectName string) (string, error)

Resolve looks up the target type for a canonical type name in the given dialect. Returns ErrUnknownDialect if the dialect does not exist. Returns ErrUnmappedType if the canonical type has no mapping in the dialect.