theme

Documentation

Overview

Package theme provides color palettes for syntax highlighting.

Index

• Constants
• func SetEnvPrefix(prefix string)
• type Background
  • func DetectBackground(out *os.File) (Background, bool)
  • func (b Background) String() string
• type Pair
  • func DefaultPair(opts ...PairOption) *Pair
  • func FromEnv(opts ...PairOption) (*Pair, error)
  • func MustPair(light, dark *Theme, opts ...PairOption) *Pair
  • func NewPair(light, dark *Theme, opts ...PairOption) (*Pair, error)
  • func PairFromEnv(opts ...PairOption) (*Pair, error)
  • func Single(t *Theme) *Pair
  • func (p *Pair) Auto(files ...*os.File) *Theme
  • func (p *Pair) ForBackground(bg Background) *Theme
  • func (p *Pair) ForTerminal(out *os.File) *Theme
• type PairOption
  • func WithFallback(bg Background) PairOption
• type Theme
  • func Auto(files ...*os.File) *Theme
  • func CatppuccinFrappe() *Theme
  • func CatppuccinLatte() *Theme
  • func CatppuccinMacchiato() *Theme
  • func CatppuccinMocha() *Theme
  • func Dark() *Theme
  • func Dracula() *Theme
  • func Light() *Theme
  • func Monokai() *Theme
  • func (t *Theme) MarshalText() ([]byte, error)
  • func (t *Theme) Name() string
  • func (t *Theme) UnmarshalText(text []byte) error

Constants

const DefaultEnvPrefix = "CLOG"

DefaultEnvPrefix is the default environment variable prefix.

Functions

func SetEnvPrefix

func SetEnvPrefix(prefix string)

SetEnvPrefix sets a custom environment variable prefix. The prefix is process-wide and shared with root clog.

theme.SetEnvPrefix("MYAPP")
// Now checks MYAPP_THEME_LIGHT/MYAPP_THEME_DARK first, then CLOG_THEME_LIGHT/CLOG_THEME_DARK

Types

type Background

type Background int

Background describes the terminal background a theme is designed for.

const (
	BackgroundUnspecified Background = iota
	BackgroundLight
	BackgroundDark
)

func DetectBackground

func DetectBackground(out *os.File) (Background, bool)

DetectBackground queries a terminal for its background color.

func (Background) String

func (b Background) String() string

type Pair

type Pair struct {
	Light    *Theme
	Dark     *Theme
	Fallback Background
}

Pair holds the light and dark themes an application supports.

func DefaultPair

func DefaultPair(opts ...PairOption) *Pair

DefaultPair returns clog's built-in light/dark theme pair.

func FromEnv

func FromEnv(opts ...PairOption) (*Pair, error)

FromEnv resolves theme configuration from the environment.

Precedence:

1. <PREFIX>_THEME selects an explicit theme, wrapped via Single so the same theme applies regardless of the terminal background.
2. <PREFIX>_THEME_LIGHT and <PREFIX>_THEME_DARK select a light/dark pair.

It returns (nil, nil) when no theme variables are set. A set-but-invalid value returns an error.

func MustPair

func MustPair(light, dark *Theme, opts ...PairOption) *Pair

MustPair creates a theme pair and panics if it is invalid.

func NewPair

func NewPair(light, dark *Theme, opts ...PairOption) (*Pair, error)

NewPair creates a theme pair with one light theme and one dark theme.

func PairFromEnv

func PairFromEnv(opts ...PairOption) (*Pair, error)

PairFromEnv builds a theme pair from <PREFIX>_THEME_LIGHT and <PREFIX>_THEME_DARK.

func Single

func Single(t *Theme) *Pair

Single returns a Pair that renders t on both light and dark backgrounds, bypassing the light/dark validation that NewPair performs. Background detection still runs but has no visible effect.

func (*Pair) Auto

func (p *Pair) Auto(files ...*os.File) *Theme

Auto selects from the pair using the terminal background. Defaults to os.Stdout if no files are provided. All provided files must report the same background, otherwise the pair fallback is used.

func (*Pair) ForBackground

func (p *Pair) ForBackground(bg Background) *Theme

ForBackground returns the theme matching bg.

func (*Pair) ForTerminal

func (p *Pair) ForTerminal(out *os.File) *Theme

ForTerminal queries out and returns the theme matching its terminal background.

type PairOption

type PairOption func(*Pair)

PairOption configures a theme Pair.

func WithFallback

func WithFallback(bg Background) PairOption

WithFallback sets the background used when terminal detection is unavailable.

type Theme

type Theme struct {

	// Background declares the terminal background this theme is designed for.
	Background Background

	Accent     color.Color // type-level identifiers (block types, table headers, datetime, anchors)
	BoolFalse  color.Color // false, no, off
	BoolTrue   color.Color // true, yes, on
	Comment    color.Color // comments, null, tags
	Foreground color.Color // punctuation, structural tokens
	Key        color.Color // mapping/attribute keys
	Number     color.Color // numeric values
	Secondary  color.Color // secondary keys (nested keys)
	String     color.Color // string values
	// contains filtered or unexported fields
}

Theme defines a named color palette for syntax highlighting.

func Auto

func Auto(files ...*os.File) *Theme

Auto selects from clog's built-in themes using the terminal background. Defaults to os.Stdout if no files are provided.

func CatppuccinFrappe

func CatppuccinFrappe() *Theme

CatppuccinFrappe returns the Catppuccin Frappe (dark) color theme.

func CatppuccinLatte

func CatppuccinLatte() *Theme

CatppuccinLatte returns the Catppuccin Latte (light) color theme.

func CatppuccinMacchiato

func CatppuccinMacchiato() *Theme

CatppuccinMacchiato returns the Catppuccin Macchiato (dark) color theme.

func CatppuccinMocha

func CatppuccinMocha() *Theme

CatppuccinMocha returns the Catppuccin Mocha (dark) color theme.

func Dark

func Dark() *Theme

Dark returns clog's default dark-background color theme.

This intentionally preserves the colors that clog used before light/dark theme selection was added.

func Dracula

func Dracula() *Theme

Dracula returns the Dracula color theme.

func Light

func Light() *Theme

Light returns clog's default light-background color theme.

func Monokai

func Monokai() *Theme

Monokai returns the Monokai color theme.

func (*Theme) MarshalText

func (t *Theme) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler.

func (*Theme) Name

func (t *Theme) Name() string

Name returns the preset name for built-in themes, or "custom" for themes that were modified programmatically.

func (*Theme) UnmarshalText

func (t *Theme) UnmarshalText(text []byte) error

UnmarshalText implements encoding.TextUnmarshaler.