syntax library

TextMate-grammar syntax highlighting in pure Dart.

import 'package:syntax_core/syntax.dart';
import 'package:syntax_core/langs/dart.dart';
import 'package:syntax_core/themes/github_dark.dart';

final highlighter = Highlighter(languages: [dartLanguage]);
print(highlighter.toAnsi(code, language: 'dart', theme: githubDarkTheme));

Bundled grammars live under package:syntax_core/langs/ and themes under package:syntax_core/themes/. Import only the ones you need, so the rest are tree-shaken. Any VS Code grammar or theme JSON can also be loaded at runtime with Language.fromJson and SyntaxTheme.fromJson.

Classes

DartRegexEngine: The default engine. It translates Oniguruma to ECMAScript and runs Dart's built-in RegExp, which is the browser's native engine on the web.
DiffColors: The colors a diff view uses, from a theme's diffEditor.* and editorGutter.* colors, with fallbacks for themes that leave them out. Colors are ARGB integers. Line and word backgrounds are translucent, to paint over the editor background; the chrome colors are opaque.
DiffFileHeaderRow: A file's header: its path, status and change counts. Only files with a path get one.
DiffGapRow: Unchanged lines that are not shown, which a view can offer to expand.
DiffHighlightCache: The highlighting and word changes a diff view needs per file, computed the first time a file is asked for.
DiffHunk: A run of changes with its surrounding context, the part of a patch that starts with @@ -oldStart,oldCount +newStart,newCount @@.
DiffHunkHeaderRow: The @@ line that starts a hunk.
DiffLabels: The words a diff view shows, and announces to screen readers.
DiffLayout: Random-access layout storing runs instead of one object per visible line. Constructing and expanding a large context region costs one block, while accessing an individual row takes logarithmic time.
DiffLine: One line of a hunk.
DiffLineRow: One line in DiffMode.unified.
DiffNoticeRow: Shown in place of a file's lines.
DiffPairRow: One row in DiffMode.split. A context line is on both sides; a removed line without an added partner, or the reverse, leaves one side empty.
DiffRow: One row of a diff view, as laid out by layoutDiff.
DiffSegment: A piece of a diff line with one style. changed marks the words that differ from the paired line, which views give a stronger background.
DocumentLine: One line of a TokenizedDocument.
FileDiff: The changes to one file.
Grammar: A compiled TextMate grammar.
HighlightedDiff: Syntax colors for both sides of a FileDiff.
Highlighter: Tokenizes and themes code with TextMate grammars.
HtmlDecoration: Safe token decoration for static HTML output. Text and attributes are escaped.
Language: A language a Highlighter can tokenize: a TextMate grammar plus its name and aliases.
LineTokens: The tokens of one line, and the state to pass to the next line.
RegexEngine: A regex backend for the tokenizer.
RowHeightIndex: Prefix sums for measured row heights. Updates and lookup are logarithmic.
ScanMatch: One scanner match. Offsets are UTF-16 code unit indices into the line. A group that did not take part in the match reports -1.
Scanner: Finds the earliest match among a fixed list of patterns.
ScopeStack: An immutable stack of scope names, innermost last, for example source.dart > string.interpolated.single.dart.
StateStack: Tokenizer state at a line boundary: the stack of open grammar rules.
StyledRange: A run of text with one style, as UTF-16 offsets into a whole document.
SyntaxTheme: A VS Code color theme: the JSON of a *-color-theme.json file.
ThemedToken: A token with its text and resolved style.
Token: A run of text with the scopes that apply to it.
TokenFontStyle: Font style flags. They can be combined, for example TokenFontStyle.bold | TokenFontStyle.italic.
TokenizedDocument: A document whose lines stay tokenized as its text changes.
TokenStyle: The resolved look of a token. Colors are ARGB integers, as 0xAARRGGBB.
WordChanges: The changed words within edited lines, for highlighting what changed inside a line rather than only which lines changed.

Enums

DiffIndicators: Change markers independent of line background colors.
DiffLineKind: The role of a line in a diff.
DiffMode: How a diff view arranges changed lines.
DiffNotice: Why a file shows a notice instead of lines. Renderers choose the wording.
FileDiffKind: What happened to a file.
HunkSeparatorStyle: Built-in presentation of context gaps and section metadata.
InlineDiffMode: Inline comparison policy, independent of the surrounding line diff. Granularity of bounded inline change highlighting.

Extensions

HighlighterRendering on Highlighter: One-call rendering helpers.

Functions

alphaBlend(int foreground, int background) → int: Paints foreground over background and returns the opaque result, like Flutter's Color.alphaBlend. Both are ARGB integers. For renderers that can't blend, such as terminals.
colorToHex(int argb) → String: Formats an ARGB color as #rrggbb, or #rrggbbaa if not opaque.
diffTexts(String oldText, String newText, {String path = '', int contextLines = 3, bool indentHeuristic = true, String? id, int revision = 0, String? language}) → FileDiff: Compares two versions of a file line by line, like git diff.
layoutDiff(List<FileDiff> files, {DiffMode mode = DiffMode.unified, Set<int> collapsed = const {}, Set<DiffGapId> expanded = const {}}) → List<DiffRow>: Lays out files as the rows a diff view shows, top to bottom.
parseHexColor(String? hex) → int?: Parses #rgb, #rgba, #rrggbb or #rrggbbaa to ARGB. Returns null for anything else.
parsePatch(String patch) → List<FileDiff>: Parses a unified diff, such as the output of git diff or diff -u, into one FileDiff per file.
renderAnsi(List<List<ThemedToken>> lines, SyntaxTheme theme, {bool background = false}) → String: Renders highlighted lines with 24-bit ANSI escape codes, for terminals. Set background to paint the theme's background across each full row.
renderDiffHtml(Iterable<FileDiff> files, {required Highlighter highlighter, required Map<String, SyntaxTheme> themes, DiffMode mode = DiffMode.unified, InlineDiffMode inlineDiffMode = InlineDiffMode.mergedWords, bool expandAll = false, bool wrap = false, HtmlDecoration? decorateLine(FileDiff file, DiffLine line)?}) → String: Renders a static file patch with unified or aligned split rows.
renderHtml(List<List<ThemedToken>> lines, SyntaxTheme theme) → String: Renders highlighted lines as a <pre> block with inline styles, in the same shape as Shiki's codeToHtml.
splitLines(String code) → List<String>: Splits code into lines on \n, dropping a \r before each break.
themeTokens(String line, List<Token> tokens, SyntaxTheme theme) → List<ThemedToken>: Applies theme to one line's raw tokens, merging adjacent tokens with the same style. tokens must come from tokenizing line.

Typedefs

CharRange = ({int end, int start}): A half-open range of UTF-16 offsets within a line.
DiffGapId = ({int file, int hunk}): The unchanged lines before hunk hunk of file file, or after the file's last hunk when hunk equals its hunk count.
GapExpansion = ({int after, int before}): Number of context lines revealed from the beginning and end of a gap.
GrammarLookup = Map<String, Object?>? Function(String scopeName): Looks up grammars by scope name, for include: "source.other".
InjectionLookup = List<String> Function(String code): Scope names of grammars that inject into scopeName through their injectionSelector, such as a SQL-in-template-strings grammar for source.js.
UnsupportedPatternCallback = void Function(String pattern, Object error): Called for a pattern that the engine cannot compile. Such a pattern never matches, and the rest of the grammar keeps working.

Exceptions / Errors

UnsupportedPatternException: An Oniguruma pattern that has no ECMAScript equivalent, such as one using absent operators.

syntax library

Classes

Enums

Extensions

Functions

Typedefs

Exceptions / Errors

syntax_core package

syntax library