Chroma Adapter

The kazarichroma package connects Kazari to Chroma for pure Go syntax highlighting with zero external dependencies and negligible initialization time. All Kazari presentation features work identically regardless of which adapter is used.

Setup

Install Kazari and Chroma:

go get github.com/frostybee/kazari@latest
go get github.com/alecthomas/chroma/v2@latest

Wire the adapter at engine construction:

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import (
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    "github.com/frostybee/kazari"
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    kazarichroma "github.com/frostybee/kazari/chroma"
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)
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chromaHL := kazarichroma.New(kazarichroma.WithStyleMap(map[string]string{
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    "github-light":        "github",
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    "github-dark-default": "github-dark",
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}))
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engine := kazari.New(
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    kazari.WithHighlighter(chromaHL),
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    kazari.WithThemes("github-light", "github-dark-default"),
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)

No context is required. There is no Close method and no deferred cleanup.

Style map

Kazari theme names and Chroma style names use different naming conventions. kazarichroma.WithStyleMap bridges them:

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kazarichroma.WithStyleMap(map[string]string{
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    "github-light":        "github",
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    "github-dark-default": "github-dark",
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    "one-dark-pro":        "monokai",
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})

Keys are the theme names passed to kazari.WithThemes(). Values are Chroma style names as returned by Chroma's styles.Names() registry.

Without a style map, theme names are passed directly to Chroma's styles.Get().

Available styles

Chroma ships with 74+ built-in styles. Common light/dark pairs for dual-theme rendering:

Light	Dark
`github`	`github-dark`
`solarized-light`	`solarized-dark`
`gruvbox-light`	`gruvbox`
`catppuccin-latte`	`catppuccin-mocha`
`tokyonight-day`	`tokyonight-night`
`rose-pine-dawn`	`rose-pine`
`paraiso-light`	`paraiso-dark`
`modus-operandi`	`modus-vivendi`

For the full list, call styles.Names() from github.com/alecthomas/chroma/v2/styles.

Language names

The engine resolves language names via its internal ResolveLanguage() before passing them to the adapter. Pass lowercase names to Kazari regardless of what Chroma's registry uses internally.

Chroma supports 400+ languages. Call lexers.Names(false) from github.com/alecthomas/chroma/v2/lexers for the full list of canonical names.

Theme colors

GetThemeColors populates ThemeInfo from the Chroma style:

Field	Source
`FG`	Chroma `Text` entry foreground; falls back to `Background` entry foreground
`BG`	Chroma `Background` entry background
`LineNumberFG`	Chroma `LineNumbers` entry foreground
`SelectionBG`	Always empty (Chroma has no selection color)
`FoldBG`	Always empty (Chroma has no fold color)

GetThemeColors never returns an error. An unknown style name silently produces a Fallback-based ThemeInfo with minimal color data.

Configuration

Option	Default	Description
`WithStyleMap(map[string]string)`	`nil`	Map Kazari theme names to Chroma style names

Differences from Nuri

Aspect	Nuri	Chroma
Initialization	Requires context and `nuri.New()`	Instant, no context
`DualThemeTokenizer`	Yes (one tokenization pass)	No (engine calls `Tokenize` twice)
Theme source	VS Code / Shiki themes (TextMate)	Chroma built-in styles
Theme name mapping	None needed	`WithStyleMap` required for most setups
Token granularity	Hierarchical TextMate scopes	~92 flat Pygments token types
`SelectionBG` in `ThemeInfo`	Populated from theme	Always empty
`FoldBG` in `ThemeInfo`	Populated from theme	Always empty
`GetThemeColors` error	Returns error for unknown theme	Always returns nil
Unknown language	Returns error (engine falls back to plaintext)	Returns error (engine falls back to plaintext)
Strikethrough font style	Supported	Not mapped
Binary size overhead	~400KB (embedded WASM)	~0 (pure Go)
Language count	257 (core: 39, full: 258)	~400

Because ChromaHighlighter does not implement DualThemeTokenizer, the engine calls Tokenize once for the light theme and once for the dark theme when dual-theme rendering is active. For large code blocks this doubles the tokenization work compared to the Nuri adapter. In practice, Chroma's tokenization is fast enough that this has minimal impact on total render time.