diff --git a/.vscode/tape-atom-syntax/classifier.js b/.vscode/tape-atom-syntax/classifier.js
new file mode 100644
index 0000000..a3ccdd5
--- /dev/null
+++ b/.vscode/tape-atom-syntax/classifier.js
@@ -0,0 +1,195 @@
+"use strict";
+
+const { nearestCall } = require("./lexer");
+const { mergeIndexes, scanSource } = require("./source-index");
+
+const TOKEN_TYPES = [
+	"tapeAtomKeyword",
+	"tapeAtomName",
+	"tapeComponentKeyword",
+	"tapeComponentName",
+	"tapeAnnotation",
+	"tapeBindType",
+	"tapePhase",
+	"tapeLabel",
+	"tapeCpuInstruction",
+	"tapeControlFlow",
+	"tapeGteInstruction",
+	"tapeGpuInstruction",
+	"tapeComponentInstruction",
+	"tapeDelaySlot",
+	"tapeGprRegister",
+	"tapeCop2Register",
+	"tapeDuffleType",
+	"tapeAttribute",
+];
+
+const TOKEN_MODIFIERS = ["declaration", "tapeRead", "tapeWrite", "tapeAuto"];
+const TOKEN_TYPE_INDEX = new Map(TOKEN_TYPES.map((name, index) => [name, index]));
+const TOKEN_MODIFIER_INDEX = new Map(TOKEN_MODIFIERS.map((name, index) => [name, index]));
+
+const ATOM_KEYWORDS = new Set(["MipsAtom_", "MipsAtom_Proc_"]);
+const COMPONENT_KEYWORDS = new Set(["MipsAtomComp_", "MipsAtomComp_Proc_"]);
+const ANNOTATIONS = new Set([
+	"atom_info", "atom_bind", "atom_reads", "atom_writes", "atom_label",
+	"atom_offset", "atom_reg", "atom_type", "atom_ctx", "atom_phase",
+	"atom_auto_reg", "phase_auto_reg", "atom_dbg_skip",
+]);
+
+const DELAY_SLOT_KEYWORDS = new Set(["LdSlot_", "BdSlot_"]);
+
+const CONTROL_FLOW_PREFIXES = /^(?:branch_|jump_|call_)/;
+
+const ROLE_TO_TYPE = {
+	atomName: "tapeAtomName",
+	componentName: "tapeComponentName",
+	bindType: "tapeBindType",
+	duffleType: "tapeDuffleType",
+	gprRegister: "tapeGprRegister",
+	cop2Register: "tapeCop2Register",
+};
+
+function registerType(name, index) {
+	const kind = index.registers.get(name);
+	if (kind === "gpr" || /^R_[A-Za-z0-9_]+$/.test(name)) return "tapeGprRegister";
+	if (kind === "cop2" || /^(?:C2_|gte_cr_)[A-Za-z0-9_]+$/.test(name)) return "tapeCop2Register";
+	return null;
+}
+
+function instructionType(name, index) {
+	const domain = index.macros.get(name);
+	if (domain === "cpu") return "tapeCpuInstruction";
+	if (domain === "gte") return "tapeGteInstruction";
+	if (domain === "gpu") return "tapeGpuInstruction";
+	if (domain === "component") return "tapeComponentInstruction";
+	if (/^gte_(?!cr_)/.test(name)) return "tapeGteInstruction";
+	if (/^gp[01]_/.test(name)) return "tapeGpuInstruction";
+	if (/^mac_/.test(name)) return "tapeComponentInstruction";
+	return null;
+}
+
+function modifierMask(modifiers) {
+	let mask = 0;
+	for (const modifier of modifiers) {
+		const index = TOKEN_MODIFIER_INDEX.get(modifier);
+		if (index !== undefined) mask |= (1 << index);
+	}
+	return mask;
+}
+
+function isRegUseAccess(tokens, tokenIndex) {
+	const prev = tokens[tokenIndex - 1];
+	if (!prev || prev.text !== ".") return false;
+	const prevPrev = tokens[tokenIndex - 2];
+	if (!prevPrev || prevPrev.kind !== "identifier") return false;
+	if (prevPrev.text === "r") return true;
+	const prev3 = tokens[tokenIndex - 3];
+	const prev4 = tokens[tokenIndex - 4];
+	if (prev3 && prev3.text === "." && prev4 && prev4.kind === "identifier" && prev4.text === "r") return true;
+	return false;
+}
+
+function classifyDocument(source, filePath, workspaceIndex, shouldCancel = () => false) {
+	const scanned = scanSource(source, filePath);
+	const index = mergeIndexes(workspaceIndex, scanned.index);
+	const spans = [];
+
+	for (let tokenIndex = 0; tokenIndex < scanned.tokens.length; tokenIndex += 1) {
+		if (shouldCancel()) break;
+		const token = scanned.tokens[tokenIndex];
+		if (token.kind !== "identifier") continue;
+
+		let type = null;
+		let modifiers = [];
+		const declaration = scanned.declarations.get(token.start);
+		const context = nearestCall(scanned.contexts, tokenIndex);
+
+		if (declaration) {
+			type = ROLE_TO_TYPE[declaration.role] || null;
+			modifiers = declaration.modifiers.slice();
+		} else if (ATOM_KEYWORDS.has(token.text)) {
+			type = "tapeAtomKeyword";
+		} else if (COMPONENT_KEYWORDS.has(token.text)) {
+			type = "tapeComponentKeyword";
+		} else if (ANNOTATIONS.has(token.text)) {
+			type = "tapeAnnotation";
+		} else if (context && context.callee === "atom_bind" && context.argIndex === 0) {
+			type = "tapeBindType";
+		} else if (context && context.callee === "atom_phase" && context.argIndex === 0) {
+			type = "tapePhase";
+			modifiers = ["declaration"];
+		} else if (context && context.callee === "atom_ctx" && context.argIndex === 0) {
+			type = "tapeAtomName";
+		} else if (context && context.callee === "atom_label" && context.argIndex === 0) {
+			type = "tapeLabel";
+			modifiers = ["declaration"];
+		} else if (context && context.callee === "atom_offset" && context.argIndex <= 1) {
+			type = "tapeLabel";
+		} else if (context && context.callee === "atom_reads") {
+			type = registerType(token.text, index);
+			if (type) modifiers = ["tapeRead"];
+		} else if (context && context.callee === "atom_writes") {
+			type = registerType(token.text, index);
+			if (type) modifiers = ["tapeWrite"];
+		} else if (context && context.callee === "atom_auto_reg") {
+			if (context.argIndex === 0) type = "tapeAtomName";
+			if (context.argIndex === 1) {
+				type = "tapeGprRegister";
+				modifiers = ["declaration", "tapeAuto"];
+			}
+		} else if (context && context.callee === "phase_auto_reg") {
+			if (context.argIndex === 0) type = "tapePhase";
+			if (context.argIndex === 1) {
+				type = "tapeGprRegister";
+				modifiers = ["declaration", "tapeAuto"];
+			}
+		}
+
+		if (!type && index.bindTypes.has(token.text)) type = "tapeBindType";
+		if (!type && index.types.has(token.text)) type = "tapeDuffleType";
+		if (!type && index.attributes.has(token.text)) type = "tapeAttribute";
+		if (!type) type = registerType(token.text, index);
+		if (!type && DELAY_SLOT_KEYWORDS.has(token.text)) type = "tapeDelaySlot";
+		if (!type) {
+			const domain = index.macros.get(token.text);
+			if (domain && CONTROL_FLOW_PREFIXES.test(token.text)) {
+				type = "tapeControlFlow";
+			}
+		}
+		if (!type && isRegUseAccess(scanned.tokens, tokenIndex)) type = "tapeGprRegister";
+		if (!type) type = instructionType(token.text, index);
+		if (!type && index.atoms.has(token.text)) type = "tapeAtomName";
+		if (!type && index.components.has(token.text)) type = "tapeComponentName";
+		if (!type && index.phases.has(token.text)) type = "tapePhase";
+		if (!type && index.labels.has(token.text)) type = "tapeLabel";
+		if (!type) continue;
+
+		spans.push({
+			text: token.text,
+			type,
+			typeIndex: TOKEN_TYPE_INDEX.get(type),
+			modifiers,
+			modifierMask: modifierMask(modifiers),
+			start: token.start,
+			length: token.end - token.start,
+			line: token.line,
+			character: token.character,
+		});
+	}
+
+	spans.sort((left, right) => left.start - right.start || left.length - right.length);
+	const nonOverlapping = [];
+	for (const span of spans) {
+		const previous = nonOverlapping[nonOverlapping.length - 1];
+		if (!previous || previous.start + previous.length <= span.start) nonOverlapping.push(span);
+	}
+
+	return { spans: nonOverlapping, errors: scanned.errors };
+}
+
+module.exports = {
+	TOKEN_MODIFIERS,
+	TOKEN_TYPES,
+	classifyDocument,
+	modifierMask,
+};
diff --git a/.vscode/tape-atom-syntax/extension.js b/.vscode/tape-atom-syntax/extension.js
new file mode 100644
index 0000000..e8a35f6
--- /dev/null
+++ b/.vscode/tape-atom-syntax/extension.js
@@ -0,0 +1,111 @@
+"use strict";
+
+const vscode = require("vscode");
+const { TOKEN_MODIFIERS, TOKEN_TYPES, classifyDocument } = require("./classifier");
+const { createIndex, mergeIndexes, scanSource } = require("./source-index");
+
+const SOURCE_GLOB = "**/*.{c,h,cc,cpp,cxx,hh,hpp,hxx}";
+const EXCLUDE_GLOB = "**/{gen,build,.slop_cache,toolchain,node_modules}/**";
+const EXCLUDED_SEGMENTS = new Set(["gen", "build", ".slop_cache", "toolchain", "node_modules"]);
+
+function isExcluded(uri) {
+	const segments = uri.fsPath.replaceAll("\\", "/").split("/");
+	return segments.some((segment) => EXCLUDED_SEGMENTS.has(segment));
+}
+
+function formatError(filePath, error) {
+	return `${filePath}:${error.offset}: ${error.kind}`;
+}
+
+async function activate(context) {
+	const output = vscode.window.createOutputChannel("Tape Atom DSL");
+	const emitter = new vscode.EventEmitter();
+	const legend = new vscode.SemanticTokensLegend(TOKEN_TYPES, TOKEN_MODIFIERS);
+	let workspaceIndex = createIndex();
+	let rebuildGeneration = 0;
+	let debounceHandle = null;
+
+	async function rebuildIndex() {
+		const generation = ++rebuildGeneration;
+		const files = await vscode.workspace.findFiles(SOURCE_GLOB, EXCLUDE_GLOB);
+		let nextIndex = createIndex();
+
+		for (const uri of files) {
+			if (generation !== rebuildGeneration) return;
+			if (isExcluded(uri)) continue;
+			try {
+				const bytes = await vscode.workspace.fs.readFile(uri);
+				const source = Buffer.from(bytes).toString("utf8");
+				const result = scanSource(source, uri.fsPath);
+				nextIndex = mergeIndexes(nextIndex, result.index);
+				for (const error of result.errors) output.appendLine(formatError(uri.fsPath, error));
+			} catch (error) {
+				output.appendLine(`${uri.fsPath}: ${error.stack || error.message || error}`);
+			}
+		}
+
+		if (generation !== rebuildGeneration) return;
+		workspaceIndex = nextIndex;
+		emitter.fire();
+	}
+
+	function scheduleRebuild(uri) {
+		if (uri && isExcluded(uri)) return;
+		if (debounceHandle !== null) clearTimeout(debounceHandle);
+		debounceHandle = setTimeout(() => {
+			debounceHandle = null;
+			rebuildIndex().catch((error) => output.appendLine(error.stack || String(error)));
+		}, 100);
+	}
+
+	const provider = {
+		onDidChangeSemanticTokens: emitter.event,
+		provideDocumentSemanticTokens(document, cancellationToken) {
+			try {
+				const result = classifyDocument(
+					document.getText(),
+					document.uri.fsPath,
+					workspaceIndex,
+					() => cancellationToken.isCancellationRequested
+				);
+				const builder = new vscode.SemanticTokensBuilder(legend);
+				for (const span of result.spans) {
+					if (cancellationToken.isCancellationRequested) break;
+					builder.push(span.line, span.character, span.length, span.typeIndex, span.modifierMask);
+				}
+				for (const error of result.errors) {
+					output.appendLine(formatError(document.uri.fsPath || document.uri.toString(), error));
+				}
+				return builder.build();
+			} catch (error) {
+				output.appendLine(`${document.uri}: ${error.stack || error.message || error}`);
+				return new vscode.SemanticTokensBuilder(legend).build();
+			}
+		},
+	};
+
+	const selector = [
+		{ language: "c", scheme: "file" },
+		{ language: "c", scheme: "untitled" },
+		{ language: "cpp", scheme: "file" },
+		{ language: "cpp", scheme: "untitled" },
+	];
+	const watcher = vscode.workspace.createFileSystemWatcher(SOURCE_GLOB);
+
+	context.subscriptions.push(
+		output,
+		emitter,
+		watcher,
+		watcher.onDidCreate(scheduleRebuild),
+		watcher.onDidChange(scheduleRebuild),
+		watcher.onDidDelete(scheduleRebuild),
+		vscode.languages.registerDocumentSemanticTokensProvider(selector, provider, legend),
+		{ dispose() { if (debounceHandle !== null) clearTimeout(debounceHandle); } }
+	);
+
+	await rebuildIndex();
+}
+
+function deactivate() {}
+
+module.exports = { activate, deactivate };
diff --git a/.vscode/tape-atom-syntax/lexer.js b/.vscode/tape-atom-syntax/lexer.js
new file mode 100644
index 0000000..bfe6908
--- /dev/null
+++ b/.vscode/tape-atom-syntax/lexer.js
@@ -0,0 +1,186 @@
+"use strict";
+
+function isIdentifierStart(code) {
+	return code === 95 ||
+		(code >= 65 && code <= 90) ||
+		(code >= 97 && code <= 122);
+}
+
+function isIdentifierContinue(code) {
+	return isIdentifierStart(code) || (code >= 48 && code <= 57);
+}
+
+function lex(source) {
+	if (typeof source !== "string") throw new TypeError("source must be a string");
+
+	const tokens = [];
+	const errors = [];
+	let offset = 0;
+	let line = 0;
+	let character = 0;
+
+	function advance() {
+		if (source[offset] === "\r" && source[offset + 1] === "\n") {
+			offset += 2;
+			line += 1;
+			character = 0;
+			return;
+		}
+		if (source[offset] === "\n") {
+			offset += 1;
+			line += 1;
+			character = 0;
+			return;
+		}
+		offset += 1;
+		character += 1;
+	}
+
+	function pushToken(kind, start, startLine, startCharacter) {
+		tokens.push({
+			kind,
+			text: source.slice(start, offset),
+			start,
+			end: offset,
+			line: startLine,
+			character: startCharacter,
+		});
+	}
+
+	while (offset < source.length) {
+		const ch = source[offset];
+
+		if (/\s/.test(ch)) {
+			advance();
+			continue;
+		}
+
+		if (ch === "/" && source[offset + 1] === "/") {
+			while (offset < source.length && source[offset] !== "\r" && source[offset] !== "\n") advance();
+			continue;
+		}
+
+		if (ch === "/" && source[offset + 1] === "*") {
+			const start = offset;
+			advance();
+			advance();
+			let closed = false;
+			while (offset < source.length) {
+				if (source[offset] === "*" && source[offset + 1] === "/") {
+					advance();
+					advance();
+					closed = true;
+					break;
+				}
+				advance();
+			}
+			if (!closed) errors.push({ kind: "unterminated-block-comment", offset: start });
+			continue;
+		}
+
+		if (ch === "\"" || ch === "'") {
+			const quote = ch;
+			const start = offset;
+			advance();
+			let closed = false;
+			while (offset < source.length) {
+				if (source[offset] === "\\") {
+					advance();
+					if (offset < source.length) advance();
+					continue;
+				}
+				if (source[offset] === quote) {
+					advance();
+					closed = true;
+					break;
+				}
+				if (source[offset] === "\n" || source[offset] === "\r") break;
+				advance();
+			}
+			if (!closed) errors.push({ kind: "unterminated-literal", offset: start });
+			continue;
+		}
+
+		const code = source.charCodeAt(offset);
+		if (isIdentifierStart(code)) {
+			const start = offset;
+			const startLine = line;
+			const startCharacter = character;
+			advance();
+			while (offset < source.length && isIdentifierContinue(source.charCodeAt(offset))) advance();
+			pushToken("identifier", start, startLine, startCharacter);
+			continue;
+		}
+
+		const start = offset;
+		const startLine = line;
+		const startCharacter = character;
+		advance();
+		pushToken("punctuation", start, startLine, startCharacter);
+	}
+
+	return { tokens, errors };
+}
+
+function buildCallContexts(tokens) {
+	const contexts = Array.from({ length: tokens.length }, () => []);
+	const calls = [];
+	const errors = [];
+	const stack = [];
+
+	for (let tokenIndex = 0; tokenIndex < tokens.length; tokenIndex += 1) {
+		const token = tokens[tokenIndex];
+
+		if (token.text === ")") {
+			if (stack.length === 0) {
+				errors.push({ kind: "unmatched-close-paren", offset: token.start });
+			} else {
+				const frame = stack.pop();
+				if (frame.callee !== null) calls.push({ ...frame, closeTokenIndex: tokenIndex });
+			}
+		}
+
+		contexts[tokenIndex] = stack
+			.filter((frame) => frame.callee !== null)
+			.map((frame) => ({
+				callee: frame.callee,
+				calleeTokenIndex: frame.calleeTokenIndex,
+				openTokenIndex: frame.openTokenIndex,
+				argIndex: frame.argIndex,
+			}));
+
+		if (token.text === "(") {
+			const previous = tokens[tokenIndex - 1];
+			const hasCallee = previous && previous.kind === "identifier";
+			stack.push({
+				callee: hasCallee ? previous.text : null,
+				calleeTokenIndex: hasCallee ? tokenIndex - 1 : -1,
+				openTokenIndex: tokenIndex,
+				argIndex: 0,
+			});
+			continue;
+		}
+
+		if (token.text === "," && stack.length > 0) {
+			const frame = stack[stack.length - 1];
+			if (frame.callee !== null) frame.argIndex += 1;
+		}
+	}
+
+	for (const frame of stack) {
+		errors.push({ kind: "unmatched-open-paren", offset: tokens[frame.openTokenIndex].start });
+	}
+
+	return { contexts, calls, errors };
+}
+
+function nearestCall(contexts, tokenIndex, callee) {
+	const entries = contexts[tokenIndex] || [];
+	for (let contextIndex = entries.length - 1; contextIndex >= 0; contextIndex -= 1) {
+		const entry = entries[contextIndex];
+		if (callee === undefined || entry.callee === callee) return entry;
+	}
+	return null;
+}
+
+module.exports = { buildCallContexts, lex, nearestCall };
diff --git a/.vscode/tape-atom-syntax/package.json b/.vscode/tape-atom-syntax/package.json
new file mode 100644
index 0000000..c58e883
--- /dev/null
+++ b/.vscode/tape-atom-syntax/package.json
@@ -0,0 +1,81 @@
+{
+	"name": "tape-atom-syntax",
+	"displayName": "Tape Atom DSL",
+	"description": "Source-derived semantic highlighting for the Tape/Atom MIPS macro DSL",
+	"publisher": "local",
+	"version": "0.2.0",
+	"engines": { "vscode": "^1.80.0" },
+	"categories": ["Programming Languages"],
+	"activationEvents": ["onLanguage:c", "onLanguage:cpp"],
+	"main": "./extension.js",
+	"files": [
+		"classifier.js",
+		"extension.js",
+		"lexer.js",
+		"source-index.js",
+		"syntaxes/tape_atom.tmLanguage.json"
+	],
+	"scripts": {
+		"test": "node --test test/*.test.js",
+		"package": "npx --yes @vscode/vsce@3.6.1 package --allow-missing-repository --skip-license --out tape-atom-syntax-0.2.0.vsix"
+	},
+	"contributes": {
+		"semanticTokenTypes": [
+			{ "id": "tapeAtomKeyword", "description": "Tape atom declaration keyword" },
+			{ "id": "tapeAtomName", "description": "Tape atom name" },
+			{ "id": "tapeComponentKeyword", "description": "Tape atom component declaration keyword" },
+			{ "id": "tapeComponentName", "description": "Tape atom component name" },
+			{ "id": "tapeAnnotation", "description": "Tape atom annotation" },
+			{ "id": "tapeBindType", "description": "Tape bind structure type" },
+			{ "id": "tapePhase", "description": "Tape atom phase" },
+			{ "id": "tapeLabel", "description": "Tape atom branch label" },
+			{ "id": "tapeCpuInstruction", "description": "MIPS CPU instruction emitter" },
+			{ "id": "tapeControlFlow", "description": "MIPS branch or jump instruction" },
+			{ "id": "tapeGteInstruction", "description": "GTE instruction emitter" },
+			{ "id": "tapeGpuInstruction", "description": "GPU command emitter" },
+			{ "id": "tapeComponentInstruction", "description": "Tape atom component invocation" },
+			{ "id": "tapeDelaySlot", "description": "Load or branch delay slot annotation" },
+			{ "id": "tapeGprRegister", "description": "MIPS GPR alias" },
+			{ "id": "tapeCop2Register", "description": "COP2 data or control register alias" },
+			{ "id": "tapeDuffleType", "description": "Duffle type or type constructor" },
+			{ "id": "tapeAttribute", "description": "Duffle linkage or storage attribute" }
+		],
+		"semanticTokenModifiers": [
+			{ "id": "tapeRead", "description": "Register declared in atom_reads" },
+			{ "id": "tapeWrite", "description": "Register declared in atom_writes" },
+			{ "id": "tapeAuto", "description": "Auto-allocated register" }
+		],
+		"semanticTokenScopes": [
+			{
+				"language": "c",
+				"scopes": {
+					"tapeAtomKeyword": ["keyword.control.duffle.atom"],
+					"tapeAtomName": ["entity.name.function.duffle.atom"],
+					"tapeComponentKeyword": ["keyword.control.duffle.component"],
+					"tapeComponentName": ["entity.name.function.duffle.component"],
+					"tapeAnnotation": ["support.function.duffle.annotation"],
+					"tapeBindType": ["entity.name.type.duffle.bind"],
+					"tapePhase": ["entity.name.tag.duffle.phase"],
+					"tapeLabel": ["entity.name.label.duffle.atom"],
+					"tapeCpuInstruction": ["support.function.duffle.cpu"],
+					"tapeControlFlow": ["keyword.control.duffle.branch"],
+					"tapeGteInstruction": ["support.function.duffle.gte"],
+					"tapeGpuInstruction": ["support.function.duffle.gpu"],
+					"tapeComponentInstruction": ["support.function.duffle.component"],
+					"tapeDelaySlot": ["keyword.operator.duffle.delayslot"],
+					"tapeGprRegister": ["variable.other.constant.duffle.gpr"],
+					"tapeCop2Register": ["variable.other.constant.duffle.cop2"],
+					"tapeDuffleType": ["storage.type.duffle.type"],
+					"tapeAttribute": ["storage.modifier.duffle.attr"]
+				}
+			}
+		],
+		"grammars": [
+			{
+				"scopeName": "tape_atom.injection",
+				"path": "./syntaxes/tape_atom.tmLanguage.json",
+				"injectTo": ["source.c", "source.cpp"]
+			}
+		]
+	}
+}
diff --git a/.vscode/tape-atom-syntax/source-index.js b/.vscode/tape-atom-syntax/source-index.js
new file mode 100644
index 0000000..bd0f0b6
--- /dev/null
+++ b/.vscode/tape-atom-syntax/source-index.js
@@ -0,0 +1,222 @@
+"use strict";
+
+const path = require("node:path");
+const { buildCallContexts, lex, nearestCall } = require("./lexer");
+
+const BASE_TYPES = [
+	"B1", "B2", "B4", "B8", "F4", "F8", "S1", "S2", "S4", "S8",
+	"U1", "U2", "U4", "U8", "MipsAtom", "MipsCode", "Reg",
+];
+
+const BASE_ATTRIBUTES = [
+	"FI_", "I_", "NI_", "Relative_", "Struct_", "Enum_", "Union_",
+	"TypeR_", "TypeV_", "align_", "internal", "local_persist", "global",
+];
+
+function createIndex() {
+	return {
+		atoms: new Set(),
+		components: new Set(),
+		componentAliases: new Set(),
+		macros: new Map(),
+		registers: new Map(),
+		bindTypes: new Set(),
+		types: new Set(BASE_TYPES),
+		phases: new Set(),
+		labels: new Set(),
+		attributes: new Set(BASE_ATTRIBUTES),
+	};
+}
+
+function cloneIndex(source) {
+	const result = createIndex();
+	for (const key of ["atoms", "components", "componentAliases", "bindTypes", "types", "phases", "labels", "attributes"]) {
+		for (const value of source[key]) result[key].add(value);
+	}
+	for (const [name, domain] of source.macros) result.macros.set(name, domain);
+	for (const [name, domain] of source.registers) result.registers.set(name, domain);
+	return result;
+}
+
+function mergeIndexes(...sources) {
+	const result = createIndex();
+	for (const source of sources) {
+		if (!source) continue;
+		for (const key of ["atoms", "components", "componentAliases", "bindTypes", "types", "phases", "labels", "attributes"]) {
+			for (const value of source[key]) result[key].add(value);
+		}
+		for (const [name, domain] of source.macros) result.macros.set(name, domain);
+		for (const [name, domain] of source.registers) result.registers.set(name, domain);
+	}
+	return result;
+}
+
+function domainFromPath(filePath) {
+	const base = path.basename(filePath.replaceAll("\\", "/")).toLowerCase();
+	if (base === "mips.h" || base === "mips.atom.c") return "cpu";
+	if (base === "gte.h" || base === "gte.atom.c") return "gte";
+	if (base === "gp.h" || base === "gp.atom.c") return "gpu";
+	return "component";
+}
+
+function registerKind(name) {
+	if (/^R_[A-Za-z0-9_]+$/.test(name)) return "gpr";
+	if (/^(?:C2_|gte_cr_)[A-Za-z0-9_]+$/.test(name)) return "cop2";
+	return null;
+}
+
+function componentAlias(name) {
+	return name.startsWith("ac_") ? `mac_${name.slice(3)}` : null;
+}
+
+function findFunctionNameBefore(tokens, calleeTokenIndex) {
+	let closeIndex = calleeTokenIndex - 1;
+	while (closeIndex >= 0 && tokens[closeIndex].kind === "identifier" && tokens[closeIndex].text === "atom_dbg_skip") {
+		closeIndex -= 1;
+	}
+	if (!tokens[closeIndex] || tokens[closeIndex].text !== ")") return null;
+
+	let depth = 1;
+	for (let tokenIndex = closeIndex - 1; tokenIndex >= 0; tokenIndex -= 1) {
+		if (tokens[tokenIndex].text === ")") depth += 1;
+		if (tokens[tokenIndex].text === "(") depth -= 1;
+		if (depth !== 0) continue;
+		const name = tokens[tokenIndex - 1];
+		return name && name.kind === "identifier" ? name : null;
+	}
+	return null;
+}
+
+function scanSource(source, filePath) {
+	const lexical = lex(source);
+	const balanced = buildCallContexts(lexical.tokens);
+	const tokens = lexical.tokens;
+	const contexts = balanced.contexts;
+	const index = createIndex();
+	const declarations = new Map();
+	const domain = domainFromPath(filePath);
+
+	function mark(token, role, modifiers = ["declaration"]) {
+		declarations.set(token.start, { role, modifiers });
+	}
+
+	function addComponent(token) {
+		index.components.add(token.text);
+		mark(token, "componentName");
+		const alias = componentAlias(token.text);
+		if (alias) {
+			index.componentAliases.add(alias);
+			index.macros.set(alias, domain);
+		}
+	}
+
+	for (let tokenIndex = 0; tokenIndex < tokens.length; tokenIndex += 1) {
+		const token = tokens[tokenIndex];
+		if (token.kind !== "identifier") continue;
+
+		const kind = registerKind(token.text);
+		if (kind) {
+			index.registers.set(token.text, kind);
+			if (tokens[tokenIndex + 1] && tokens[tokenIndex + 1].text === "=") {
+				mark(token, kind === "gpr" ? "gprRegister" : "cop2Register");
+			}
+		}
+
+		const context = nearestCall(contexts, tokenIndex);
+		if (context && context.argIndex === 0) {
+			if (context.callee === "MipsAtom_") {
+				index.atoms.add(token.text);
+				mark(token, "atomName");
+			}
+			if (context.callee === "MipsAtomComp_") addComponent(token);
+			if (context.callee === "atom_bind") index.bindTypes.add(token.text);
+			if (context.callee === "atom_phase" || context.callee === "phase_auto_reg") index.phases.add(token.text);
+			if (context.callee === "atom_label" || context.callee === "atom_offset") index.labels.add(token.text);
+		}
+
+		const isWrappedType = context && (
+			((context.callee === "Struct_" || context.callee === "Union_") && context.argIndex === 0) ||
+			(context.callee === "Enum_" && context.argIndex === 1)
+		);
+		if (isWrappedType) {
+			index.types.add(token.text);
+			mark(token, token.text.startsWith("Binds_") ? "bindType" : "duffleType");
+			if (token.text.startsWith("Binds_")) index.bindTypes.add(token.text);
+		}
+
+		if (context && context.callee === "atom_offset" && context.argIndex === 1) index.labels.add(token.text);
+
+		if (context && context.callee === "atom_auto_reg") {
+			if (context.argIndex === 0) index.atoms.add(token.text);
+			if (context.argIndex === 1) {
+				index.registers.set(token.text, "gpr");
+				mark(token, "gprRegister", ["declaration", "tapeAuto"]);
+			}
+		}
+
+		if (context && context.callee === "phase_auto_reg" && context.argIndex === 1) {
+			index.registers.set(token.text, "gpr");
+			mark(token, "gprRegister", ["declaration", "tapeAuto"]);
+		}
+
+		if (token.text === "define" && tokens[tokenIndex - 1] && tokens[tokenIndex - 1].text === "#") {
+			const name = tokens[tokenIndex + 1];
+			if (name && name.kind === "identifier" && name.line === token.line) index.macros.set(name.text, domain);
+		}
+
+		if (token.text === "typedef") {
+			let endIndex = tokenIndex + 1;
+			let hasBrace = false;
+			let lastIdentifier = null;
+			while (endIndex < tokens.length && tokens[endIndex].text !== ";") {
+				if (tokens[endIndex].text === "{") hasBrace = true;
+				if (tokens[endIndex].kind === "identifier") lastIdentifier = tokens[endIndex];
+				endIndex += 1;
+			}
+			if (!hasBrace && lastIdentifier) {
+				index.types.add(lastIdentifier.text);
+				mark(lastIdentifier, "duffleType");
+			}
+		}
+
+		if (token.text === "MipsAtom_Proc_") {
+			const functionName = findFunctionNameBefore(tokens, tokenIndex);
+			if (functionName) {
+				const atomName = functionName.text.endsWith("_proc")
+					? functionName.text.slice(0, -5)
+					: functionName.text;
+				index.atoms.add(atomName);
+				index.atoms.add(functionName.text);
+				mark(functionName, "atomName");
+			}
+		}
+
+		if (token.text === "MipsAtomComp_Proc_") {
+			const functionName = findFunctionNameBefore(tokens, tokenIndex);
+			if (functionName) addComponent(functionName);
+		}
+	}
+
+	for (const call of balanced.calls) {
+		if (domain === "component") continue;
+		const name = tokens[call.calleeTokenIndex];
+		const after = tokens[call.closeTokenIndex + 1];
+		if (!name || !after || after.text !== "{") continue;
+		if (/^(?:gp0_|gp1_|gte_|mac_)/.test(name.text)) index.macros.set(name.text, domain);
+	}
+
+	return {
+		index: cloneIndex(index),
+		declarations,
+		tokens,
+		contexts,
+		errors: [...lexical.errors, ...balanced.errors],
+	};
+}
+
+module.exports = {
+	createIndex,
+	domainFromPath,
+	mergeIndexes,
+	scanSource,
+};
diff --git a/.vscode/tape-atom-syntax/syntaxes/tape_atom.tmLanguage.json b/.vscode/tape-atom-syntax/syntaxes/tape_atom.tmLanguage.json
new file mode 100644
index 0000000..7edf983
--- /dev/null
+++ b/.vscode/tape-atom-syntax/syntaxes/tape_atom.tmLanguage.json
@@ -0,0 +1,85 @@
+{
+	"scopeName": "tape_atom.injection",
+	"injectionSelector": "L:source.c -comment -string, L:source.cpp -comment -string",
+	"patterns": [
+		{ "include": "#atom-declarations" },
+		{ "include": "#component-declarations" },
+		{ "include": "#annotation-arguments" },
+		{ "include": "#annotations" },
+		{ "include": "#instructions" },
+		{ "include": "#registers" },
+		{ "include": "#types" },
+		{ "include": "#attributes" }
+	],
+	"repository": {
+		"atom-declarations": {
+			"patterns": [
+				{
+					"match": "\\b(MipsAtom_)\\s*\\(\\s*([A-Za-z_][A-Za-z0-9_]*)",
+					"captures": {
+						"1": { "name": "keyword.control.duffle.atom" },
+						"2": { "name": "entity.name.function.duffle.atom" }
+					}
+				},
+				{ "match": "\\bMipsAtom_Proc_\\b", "name": "keyword.control.duffle.atom" },
+				{ "match": "\\b[A-Za-z_][A-Za-z0-9_]*_proc\\b", "name": "entity.name.function.duffle.atom" }
+			]
+		},
+		"component-declarations": {
+			"patterns": [
+				{
+					"match": "\\b(MipsAtomComp_)\\s*\\(\\s*(ac_[A-Za-z0-9_]*)",
+					"captures": {
+						"1": { "name": "keyword.control.duffle.component" },
+						"2": { "name": "entity.name.function.duffle.component" }
+					}
+				},
+				{ "match": "\\bMipsAtomComp_Proc_\\b", "name": "keyword.control.duffle.component" },
+				{ "match": "\\bac_[A-Za-z0-9_]+\\b", "name": "entity.name.function.duffle.component" }
+			]
+		},
+		"annotation-arguments": {
+			"patterns": [
+				{ "match": "(?<=\\batom_bind\\()\\s*Binds_[A-Za-z0-9_]+", "name": "entity.name.type.duffle.bind" },
+				{ "match": "(?<=\\batom_phase\\()\\s*[A-Za-z_][A-Za-z0-9_]*", "name": "entity.name.tag.duffle.phase" },
+				{ "match": "(?<=\\batom_label\\()\\s*[A-Za-z_][A-Za-z0-9_]*", "name": "entity.name.label.duffle.atom" },
+				{
+					"match": "\\b(atom_offset)\\s*\\(\\s*([A-Za-z_][A-Za-z0-9_]*)\\s*,\\s*([A-Za-z_][A-Za-z0-9_]*)",
+					"captures": {
+						"1": { "name": "support.function.duffle.annotation" },
+						"2": { "name": "entity.name.label.duffle.atom" },
+						"3": { "name": "entity.name.label.duffle.atom" }
+					}
+				}
+			]
+		},
+		"annotations": {
+			"match": "\\b(atom_info|atom_bind|atom_reads|atom_writes|atom_label|atom_offset|atom_reg|atom_type|atom_ctx|atom_phase|atom_auto_reg|phase_auto_reg|atom_dbg_skip)\\b",
+			"name": "support.function.duffle.annotation"
+		},
+		"instructions": {
+			"patterns": [
+				{ "match": "\\b(branch_|jump_|jump_rel|call_)[A-Za-z0-9_]*\\b", "name": "keyword.control.duffle.branch" },
+				{ "match": "\\b(LdSlot_|BdSlot_)\\b", "name": "keyword.operator.duffle.delayslot" },
+				{ "match": "\\b(load_|store_|add_|sub_|shift_|set_lt_|and_i|or_i|xor_i|nop[0-9]*)[A-Za-z0-9_]*\\b", "name": "support.function.duffle.cpu" },
+				{ "match": "\\bgte_(?!cr_)[A-Za-z0-9_]+\\b", "name": "support.function.duffle.gte" },
+				{ "match": "\\bgp[01]_[A-Za-z0-9_]+\\b", "name": "support.function.duffle.gpu" },
+				{ "match": "\\bmac_[A-Za-z0-9_]+\\b", "name": "support.function.duffle.component" }
+			]
+		},
+		"registers": {
+			"patterns": [
+				{ "match": "\\bR_[A-Za-z0-9_]+\\b", "name": "variable.other.constant.duffle.gpr" },
+				{ "match": "\\b(?:C2_|gte_cr_)[A-Za-z0-9_]+\\b", "name": "variable.other.constant.duffle.cop2" }
+			]
+		},
+		"types": {
+			"match": "\\b(?:[USFB][1248]|MipsAtom|MipsCode|Reg|Binds_[A-Za-z0-9_]+|Struct_|Enum_|Union_|TypeR_|TypeV_)\\b",
+			"name": "storage.type.duffle.type"
+		},
+		"attributes": {
+			"match": "\\b(?:FI_|I_|NI_|Relative_|align_|internal|local_persist|global)\\b",
+			"name": "storage.modifier.duffle.attr"
+		}
+	}
+}
diff --git a/.vscode/tape-atom-syntax/tape-atom-syntax-0.2.0.vsix b/.vscode/tape-atom-syntax/tape-atom-syntax-0.2.0.vsix
new file mode 100644
index 0000000..b15f1cc
Binary files /dev/null and b/.vscode/tape-atom-syntax/tape-atom-syntax-0.2.0.vsix differ
diff --git a/.vscode/tape-atom-syntax/test/classifier.test.js b/.vscode/tape-atom-syntax/test/classifier.test.js
new file mode 100644
index 0000000..c19275d
--- /dev/null
+++ b/.vscode/tape-atom-syntax/test/classifier.test.js
@@ -0,0 +1,83 @@
+"use strict";
+
+const assert = require("node:assert/strict");
+const test = require("node:test");
+
+const { classifyDocument } = require("../classifier");
+const { createIndex } = require("../source-index");
+
+function byText(result, text) {
+	return result.spans.filter((span) => span.text === text);
+}
+
+test("classifyDocument distinguishes declaration, annotation, phase, bind, and label roles", () => {
+	const source = [
+		"typedef Struct_(Binds_CubeTri) { U4 PrimCursor; };",
+		"MipsAtom_(cube_g4_face) atom_info(atom_bind(Binds_CubeTri), atom_phase(cube_g4),",
+		"\tatom_reads(R_PrimCursor), atom_writes(R_FaceCursor)) {",
+		"\tbranch_le_zero(R_T0, atom_offset(cull, exit)),",
+		"\tatom_label(exit)",
+		"};",
+	].join("\n");
+
+	const result = classifyDocument(source, "C:/x/code/hello_camera/hello_camera.atom.c", createIndex());
+
+	assert.equal(byText(result, "MipsAtom_")[0].type, "tapeAtomKeyword");
+	assert.deepEqual(byText(result, "cube_g4_face")[0].modifiers, ["declaration"]);
+	assert.equal(byText(result, "atom_bind")[0].type, "tapeAnnotation");
+	assert.equal(byText(result, "Binds_CubeTri").at(-1).type, "tapeBindType");
+	assert.equal(byText(result, "cube_g4")[0].type, "tapePhase");
+	assert.deepEqual(byText(result, "cube_g4")[0].modifiers, ["declaration"]);
+	assert.equal(byText(result, "cull")[0].type, "tapeLabel");
+	assert.equal(byText(result, "exit").every((span) => span.type === "tapeLabel"), true);
+});
+
+test("classifyDocument applies read and write modifiers to GPRs", () => {
+	const source = "atom_info(atom_reads(R_PrimCursor), atom_writes(R_FaceCursor))";
+	const result = classifyDocument(source, "C:/x/code/test.atom.c", createIndex());
+
+	assert.deepEqual(byText(result, "R_PrimCursor")[0].modifiers, ["tapeRead"]);
+	assert.deepEqual(byText(result, "R_FaceCursor")[0].modifiers, ["tapeWrite"]);
+});
+
+test("classifyDocument separates CPU, GTE, GPU, and component domains", () => {
+	const workspace = createIndex();
+	workspace.macros.set("load_word", "cpu");
+	workspace.macros.set("gte_cmdw_rtpt", "gte");
+	workspace.macros.set("gp1_word_DisplayOn", "gpu");
+	workspace.macros.set("mac_yield", "component");
+	workspace.componentAliases.add("mac_yield");
+
+	const source = "load_word(R_T0, R_T1, 0), gte_cmdw_rtpt, gp1_word_DisplayOn(), mac_yield(), C2_MAC0, gte_cr_OFX_Code";
+	const result = classifyDocument(source, "C:/x/code/test.c", workspace);
+
+	assert.equal(byText(result, "load_word")[0].type, "tapeCpuInstruction");
+	assert.equal(byText(result, "gte_cmdw_rtpt")[0].type, "tapeGteInstruction");
+	assert.equal(byText(result, "gp1_word_DisplayOn")[0].type, "tapeGpuInstruction");
+	assert.equal(byText(result, "mac_yield")[0].type, "tapeComponentInstruction");
+	assert.equal(byText(result, "C2_MAC0")[0].type, "tapeCop2Register");
+	assert.equal(byText(result, "gte_cr_OFX_Code")[0].type, "tapeCop2Register");
+});
+
+test("document-local declarations override an empty workspace index", () => {
+	const source = [
+		"MipsAtomComp_(ac_new_component) { nop };",
+		"mac_new_component(),",
+	].join("\n");
+	const result = classifyDocument(source, "C:/x/code/duffle/math.atom.c", createIndex());
+
+	assert.equal(byText(result, "ac_new_component")[0].type, "tapeComponentName");
+	assert.equal(byText(result, "mac_new_component")[0].type, "tapeComponentInstruction");
+});
+
+test("classifier returns ordered non-overlapping spans and partial malformed output", () => {
+	const source = "atom_reads(R_A /* broken";
+	const result = classifyDocument(source, "C:/x/code/test.atom.c", createIndex());
+
+	assert.equal(result.errors.some((error) => error.kind === "unterminated-block-comment"), true);
+	for (let spanIndex = 1; spanIndex < result.spans.length; spanIndex += 1) {
+		const previous = result.spans[spanIndex - 1];
+		const current = result.spans[spanIndex];
+		assert.equal(previous.start + previous.length <= current.start, true);
+	}
+});
diff --git a/.vscode/tape-atom-syntax/test/contract.test.js b/.vscode/tape-atom-syntax/test/contract.test.js
new file mode 100644
index 0000000..05b0d31
--- /dev/null
+++ b/.vscode/tape-atom-syntax/test/contract.test.js
@@ -0,0 +1,93 @@
+"use strict";
+
+const assert = require("node:assert/strict");
+const fs = require("node:fs");
+const path = require("node:path");
+const test = require("node:test");
+
+const { TOKEN_MODIFIERS, TOKEN_TYPES } = require("../classifier");
+
+const ROOT = path.resolve(__dirname, "..");
+
+function readJson(filePath) {
+	return JSON.parse(fs.readFileSync(filePath, "utf8"));
+}
+
+function collectScopeNames(value, output = new Set()) {
+	if (Array.isArray(value)) {
+		for (const entry of value) collectScopeNames(entry, output);
+		return output;
+	}
+	if (!value || typeof value !== "object") return output;
+	if (typeof value.name === "string") output.add(value.name);
+	for (const child of Object.values(value)) collectScopeNames(child, output);
+	return output;
+}
+
+test("package semantic legend matches classifier exports", () => {
+	const packageJson = readJson(path.join(ROOT, "package.json"));
+	const contributedTypes = packageJson.contributes.semanticTokenTypes.map((entry) => entry.id);
+	const contributedModifiers = packageJson.contributes.semanticTokenModifiers.map((entry) => entry.id);
+
+	assert.equal(packageJson.version, "0.2.0");
+	assert.deepEqual(contributedTypes, TOKEN_TYPES);
+	assert.deepEqual(contributedModifiers, TOKEN_MODIFIERS.filter((name) => name !== "declaration"));
+});
+
+test("package includes runtime files only and acknowledges local-only metadata", () => {
+	const packageJson = readJson(path.join(ROOT, "package.json"));
+
+	assert.deepEqual(packageJson.files, [
+		"classifier.js",
+		"extension.js",
+		"lexer.js",
+		"source-index.js",
+		"syntaxes/tape_atom.tmLanguage.json",
+	]);
+	assert.equal(packageJson.scripts.package.includes("--allow-missing-repository"), true);
+	assert.equal(packageJson.scripts.package.includes("--skip-license"), true);
+});
+
+test("every semantic token has a TextMate fallback scope and grammar scope", () => {
+	const packageJson = readJson(path.join(ROOT, "package.json"));
+	const grammar = readJson(path.join(ROOT, "syntaxes", "tape_atom.tmLanguage.json"));
+	const mappings = packageJson.contributes.semanticTokenScopes[0].scopes;
+	const grammarScopes = collectScopeNames(grammar);
+
+	for (const tokenType of TOKEN_TYPES) {
+		assert.equal(Array.isArray(mappings[tokenType]), true, `missing scope mapping: ${tokenType}`);
+		assert.equal(mappings[tokenType].some((scope) => grammarScopes.has(scope)), true, `grammar does not emit: ${tokenType}`);
+	}
+});
+
+test("TextMate offset labels stay scoped to atom_offset calls", () => {
+	const grammar = readJson(path.join(ROOT, "syntaxes", "tape_atom.tmLanguage.json"));
+	const serialized = JSON.stringify(grammar);
+	const offsetRule = grammar.repository["annotation-arguments"].patterns
+		.find((rule) => rule.match.includes("atom_offset"));
+
+	assert.equal(serialized.includes("(?<=,)"), false);
+	assert.equal(offsetRule.captures[1].name, "support.function.duffle.annotation");
+	assert.equal(offsetRule.captures[2].name, "entity.name.label.duffle.atom");
+	assert.equal(offsetRule.captures[3].name, "entity.name.label.duffle.atom");
+});
+
+test("workspace enables semantic highlighting and colors every custom token", () => {
+	const settings = readJson(path.resolve(ROOT, "..", "settings.json"));
+	const semantic = settings["editor.semanticTokenColorCustomizations"];
+
+	assert.equal(settings["editor.semanticHighlighting.enabled"], true);
+	assert.equal(semantic.enabled, true);
+	for (const tokenType of TOKEN_TYPES) {
+		assert.equal(Object.hasOwn(semantic.rules, tokenType), true, `missing color: ${tokenType}`);
+	}
+	for (const rule of [
+		"tapeGprRegister.tapeRead",
+		"tapeGprRegister.tapeWrite",
+		"tapeCop2Register.tapeRead",
+		"tapeCop2Register.tapeWrite",
+		"*.tapeAuto",
+	]) {
+		assert.equal(Object.hasOwn(semantic.rules, rule), true, `missing modifier color: ${rule}`);
+	}
+});
diff --git a/.vscode/tape-atom-syntax/test/lexer.test.js b/.vscode/tape-atom-syntax/test/lexer.test.js
new file mode 100644
index 0000000..8d06b80
--- /dev/null
+++ b/.vscode/tape-atom-syntax/test/lexer.test.js
@@ -0,0 +1,77 @@
+"use strict";
+
+const assert = require("node:assert/strict");
+const test = require("node:test");
+
+const { buildCallContexts, lex, nearestCall } = require("../lexer");
+
+test("lex skips comments, strings, and character literals", () => {
+	const source = [
+		"MipsAtom_(visible)",
+		"// MipsAtom_(line_comment)",
+		"const char *s = \"atom_reads(R_Hidden)\";",
+		"char c = '\\''; /* gte_cmdw_hidden */",
+		"atom_reads(R_Visible)",
+	].join("\n");
+
+	const result = lex(source);
+	const identifiers = result.tokens
+		.filter((token) => token.kind === "identifier")
+		.map((token) => token.text);
+
+	assert.deepEqual(result.errors, []);
+	assert.equal(identifiers.includes("visible"), true);
+	assert.equal(identifiers.includes("R_Visible"), true);
+	assert.equal(identifiers.includes("line_comment"), false);
+	assert.equal(identifiers.includes("R_Hidden"), false);
+	assert.equal(identifiers.includes("gte_cmdw_hidden"), false);
+});
+
+test("lex reports unterminated block comments without returning comment tokens", () => {
+	const result = lex("R_Visible /* atom_reads(R_Hidden)");
+
+	assert.equal(result.tokens.some((token) => token.text === "R_Visible"), true);
+	assert.equal(result.tokens.some((token) => token.text === "R_Hidden"), false);
+	assert.deepEqual(result.errors.map((error) => error.kind), ["unterminated-block-comment"]);
+});
+
+test("line comments stop at CRLF boundaries", () => {
+	const result = lex("// atom_reads(R_Hidden)\r\natom_reads(R_Visible)\r\n");
+	const identifiers = result.tokens
+		.filter((token) => token.kind === "identifier")
+		.map((token) => token.text);
+
+	assert.equal(identifiers.includes("R_Hidden"), false);
+	assert.equal(identifiers.includes("R_Visible"), true);
+});
+
+test("balanced contexts retain multiline nesting and argument indexes", () => {
+	const source = [
+		"atom_info(",
+		"\tatom_phase(cube_g4),",
+		"\tatom_reads(R_A, nested(R_B, R_C)),",
+		"\tatom_writes(R_D)",
+		")",
+	].join("\n");
+	const lexical = lex(source);
+	const balanced = buildCallContexts(lexical.tokens);
+
+	const byText = new Map();
+	lexical.tokens.forEach((token, index) => {
+		if (token.kind === "identifier") byText.set(token.text, index);
+	});
+
+	assert.equal(nearestCall(balanced.contexts, byText.get("cube_g4")).callee, "atom_phase");
+	assert.equal(nearestCall(balanced.contexts, byText.get("R_A")).callee, "atom_reads");
+	assert.equal(nearestCall(balanced.contexts, byText.get("R_A")).argIndex, 0);
+	assert.equal(nearestCall(balanced.contexts, byText.get("R_C")).callee, "nested");
+	assert.equal(nearestCall(balanced.contexts, byText.get("R_D")).callee, "atom_writes");
+	assert.deepEqual(balanced.errors, []);
+});
+
+test("balanced contexts report unmatched parentheses", () => {
+	const lexical = lex("atom_reads(R_A");
+	const balanced = buildCallContexts(lexical.tokens);
+
+	assert.deepEqual(balanced.errors.map((error) => error.kind), ["unmatched-open-paren"]);
+});
diff --git a/.vscode/tape-atom-syntax/test/source-index.test.js b/.vscode/tape-atom-syntax/test/source-index.test.js
new file mode 100644
index 0000000..c662737
--- /dev/null
+++ b/.vscode/tape-atom-syntax/test/source-index.test.js
@@ -0,0 +1,77 @@
+"use strict";
+
+const assert = require("node:assert/strict");
+const test = require("node:test");
+
+const {
+	createIndex,
+	domainFromPath,
+	mergeIndexes,
+	scanSource,
+} = require("../source-index");
+
+test("scanSource discovers current atom and component forms", () => {
+	const source = [
+		"MipsAtom_(cube_g4_face) atom_info(atom_phase(cube_g4), atom_reads(R_PrimCursor)) { mac_yield() };",
+		"MipsAtomComp_(ac_load_pair) { load_word(R_T0, R_T1, 0) };",
+		"internal MipsAtom* normalize_proc(AtomArena_R aa) MipsAtom_Proc_(aa, { mac_yield() })",
+		"FI_ void ac_store_pair(MipsAtomBuilder_R ab) atom_dbg_skip MipsAtomComp_Proc_(ab, { store_word(R_T0, R_T1, 0) })",
+	].join("\n");
+
+	const result = scanSource(source, "C:/projects/Pikuma/ps1/code/duffle/mips.atom.c");
+
+	assert.equal(result.index.atoms.has("cube_g4_face"), true);
+	assert.equal(result.index.atoms.has("normalize"), true);
+	assert.equal(result.index.components.has("ac_load_pair"), true);
+	assert.equal(result.index.components.has("ac_store_pair"), true);
+	assert.equal(result.index.componentAliases.has("mac_load_pair"), true);
+	assert.equal(result.index.componentAliases.has("mac_store_pair"), true);
+	assert.equal(result.index.macros.get("mac_store_pair"), "cpu");
+	assert.equal(result.index.phases.has("cube_g4"), true);
+	assert.equal(result.index.registers.get("R_PrimCursor"), "gpr");
+	assert.deepEqual(result.errors, []);
+});
+
+test("scanSource discovers binds, labels, registers, typedefs, and macro domains", () => {
+	const source = [
+		"typedef Struct_(Binds_CubeTri) { U4 PrimCursor; };",
+		"typedef Enum_(U4, PadStatus) { PadStatus_Ok };",
+		"typedef U4 const MipsCode;",
+		"enum { R_PrimCursor = R_T7 atom_reg, C2_Custom = 12, gte_cr_Custom = 13 };",
+		"#define load_word(rt, base, off) enc_i(rt, base, off)",
+		"atom_bind(Binds_CubeTri)",
+		"atom_label(exit)",
+		"atom_offset(entry, exit)",
+	].join("\n");
+
+	const result = scanSource(source, "C:/projects/Pikuma/ps1/code/duffle/mips.h");
+
+	assert.equal(result.index.bindTypes.has("Binds_CubeTri"), true);
+	assert.equal(result.index.types.has("PadStatus"), true);
+	assert.equal(result.index.types.has("MipsCode"), true);
+	assert.equal(result.index.registers.get("R_PrimCursor"), "gpr");
+	assert.equal(result.index.registers.get("C2_Custom"), "cop2");
+	assert.equal(result.index.registers.get("gte_cr_Custom"), "cop2");
+	assert.equal(result.index.macros.get("load_word"), "cpu");
+	assert.equal(result.index.labels.has("entry"), true);
+	assert.equal(result.index.labels.has("exit"), true);
+});
+
+test("domainFromPath uses the declaration file rather than parent directory names", () => {
+	assert.equal(domainFromPath("C:/x/code/hello_gte/hello_gte.atom.c"), "component");
+	assert.equal(domainFromPath("C:/x/code/duffle/mips.h"), "cpu");
+	assert.equal(domainFromPath("C:/x/code/duffle/gte.atom.c"), "gte");
+	assert.equal(domainFromPath("C:/x/code/duffle/gp.h"), "gpu");
+});
+
+test("mergeIndexes preserves domain-specific aliases", () => {
+	const left = createIndex();
+	left.macros.set("load_word", "cpu");
+	const right = createIndex();
+	right.componentAliases.add("mac_gte_store");
+	right.macros.set("mac_gte_store", "gte");
+
+	const merged = mergeIndexes(left, right);
+	assert.equal(merged.macros.get("load_word"), "cpu");
+	assert.equal(merged.macros.get("mac_gte_store"), "gte");
+});