SQLite

src/fileAttachment.js

@@ -1,4 +1,5 @@
 import {require as requireDefault} from "d3-require";
+import sqlite, {SQLiteDatabaseClient} from "./sqlite.js";
 
 async function remote_fetch(file) {
   const response = await fetch(await file.url());
@@ -56,6 +57,11 @@ class FileAttachment {
       i.src = url;
     });
   }
+  async sqlite() {
+    const [SQL, buffer] = await Promise.all([sqlite(requireDefault), this.arrayBuffer()]);
+    const db = new SQL.Database(new Uint8Array(buffer));
+    return new SQLiteDatabaseClient(db);
+  }
 }
 
 export function NoFileAttachments(name) {

src/library.js

@@ -10,6 +10,7 @@ import now from "./now.js";
 import Promises from "./promises/index.js";
 import resolve from "./resolve.js";
 import requirer from "./require.js";
+import SQLite from "./sqlite.js";
 import svg from "./svg.js";
 import tex from "./tex.js";
 import vegalite from "./vegalite.js";
@@ -26,18 +27,19 @@ export default Object.assign(function Library(resolver) {
     Mutable: () => Mutable,
     Plot: () => require("@observablehq/[email protected]/dist/plot.umd.min.js"),
     Promises: () => Promises,
+    SQLite: () => SQLite(require),
     _: () => require("[email protected]/lodash.min.js"),
     d3: () => require("[email protected]/dist/d3.min.js"),
     dot: () => require("@observablehq/[email protected]/dist/graphviz.min.js"),
     htl: () => require("[email protected]/dist/htl.min.js"),
     html: () => html,
-    md: md(require),
+    md: () => md(require),
     now: now,
     require: () => require,
     resolve: () => resolve,
     svg: () => svg,
-    tex: tex(require),
-    vl: vegalite(require),
+    tex: () => tex(require),
+    vl: () => vegalite(require),
     width: width
   }));
 }, {resolve: requireDefault.resolve});

src/md.js

@@ -1,47 +1,44 @@
 import template from "./template.js";
 
-const HL_ROOT =
-  "https://cdn.jsdelivr.net/npm/@observablehq/[email protected]/";
+const HL_ROOT = "https://cdn.jsdelivr.net/npm/@observablehq/[email protected]/";
 
 export default function(require) {
-  return function() {
-    return require("[email protected]/marked.min.js").then(function(marked) {
-      return template(
-        function(string) {
-          var root = document.createElement("div");
-          root.innerHTML = marked(string, {langPrefix: ""}).trim();
-          var code = root.querySelectorAll("pre code[class]");
-          if (code.length > 0) {
-            require(HL_ROOT + "highlight.min.js").then(function(hl) {
-              code.forEach(function(block) {
-                function done() {
-                  hl.highlightBlock(block);
-                  block.parentNode.classList.add("observablehq--md-pre");
-                }
-                if (hl.getLanguage(block.className)) {
-                  done();
-                } else {
-                  require(HL_ROOT + "async-languages/index.js")
-                    .then(index => {
-                      if (index.has(block.className)) {
-                        return require(HL_ROOT +
-                          "async-languages/" +
-                          index.get(block.className)).then(language => {
-                          hl.registerLanguage(block.className, language);
-                        });
-                      }
-                    })
-                    .then(done, done);
-                }
-              });
+  return require("[email protected]/marked.min.js").then(function(marked) {
+    return template(
+      function(string) {
+        var root = document.createElement("div");
+        root.innerHTML = marked(string, {langPrefix: ""}).trim();
+        var code = root.querySelectorAll("pre code[class]");
+        if (code.length > 0) {
+          require(HL_ROOT + "highlight.min.js").then(function(hl) {
+            code.forEach(function(block) {
+              function done() {
+                hl.highlightBlock(block);
+                block.parentNode.classList.add("observablehq--md-pre");
+              }
+              if (hl.getLanguage(block.className)) {
+                done();
+              } else {
+                require(HL_ROOT + "async-languages/index.js")
+                  .then(index => {
+                    if (index.has(block.className)) {
+                      return require(HL_ROOT +
+                        "async-languages/" +
+                        index.get(block.className)).then(language => {
+                        hl.registerLanguage(block.className, language);
+                      });
+                    }
+                  })
+                  .then(done, done);
+              }
             });
-          }
-          return root;
-        },
-        function() {
-          return document.createElement("div");
+          });
         }
-      );
-    });
-  };
+        return root;
+      },
+      function() {
+        return document.createElement("div");
+      }
+    );
+  });
 }

src/sqlite.js

@@ -0,0 +1,56 @@
+export default async function sqlite(require) {
+  const sql = await require("[email protected]/dist/sql-wasm.js");
+  return sql({locateFile: file => `https://cdn.jsdelivr.net/npm/[email protected]/dist/${file}`});
+}
+
+export class SQLiteDatabaseClient {
+  constructor(db) {
+    Object.defineProperties(this, {
+      _db: {value: db}
+    });
+  }
+  async query(query, params) {
+    return await exec(this._db, query, params);
+  }
+  async queryRow(query, params) {
+    return (await this.query(query, params))[0] || null;
+  }
+  async explain(query, params) {
+    const rows = await this.query(`EXPLAIN QUERY PLAN ${query}`, params);
+    return element("pre", {className: "observablehq--inspect"}, [
+      text(rows.map(row => row.detail).join("\n"))
+    ]);
+  }
+  async describe(object) {
+    const rows = await (object === undefined
+      ? this.query(`SELECT name FROM sqlite_master WHERE type = 'table'`)
+      : this.query(`SELECT * FROM pragma_table_info(?)`, [object]));
+    if (!rows.length) throw new Error("Not found");
+    const {columns} = rows;
+    return element("table", {value: rows}, [
+      element("thead", [element("tr", columns.map(c => element("th", [text(c)])))]),
+      element("tbody", rows.map(r => element("tr", columns.map(c => element("td", [text(r[c])])))))
+    ]);
+  }
+}
+
+async function exec(db, query, params) {
+  const [result] = await db.exec(query, params);
+  if (!result) return [];
+  const {columns, values} = result;
+  const rows = values.map(row => Object.fromEntries(row.map((value, i) => [columns[i], value])));
+  rows.columns = columns;
+  return rows;
+}
+
+function element(name, props, children) {
+  if (arguments.length === 2) children = props, props = undefined;
+  const element = document.createElement(name);
+  if (props !== undefined) for (const p in props) element[p] = props[p];
+  if (children !== undefined) for (const c of children) element.appendChild(c);
+  return element;
+}
+
+function text(value) {
+  return document.createTextNode(value);
+}

src/tex.js

@@ -11,25 +11,23 @@ function style(href) {
   });
 }
 
-export default function(require) {
-  return function() {
-    return Promise.all([
-      require("@observablehq/[email protected]/dist/katex.min.js"),
-      require.resolve("@observablehq/[email protected]/dist/katex.min.css").then(style)
-    ]).then(function(values) {
-      var katex = values[0], tex = renderer();
+export default function tex(require) {
+  return Promise.all([
+    require("@observablehq/[email protected]/dist/katex.min.js"),
+    require.resolve("@observablehq/[email protected]/dist/katex.min.css").then(style)
+  ]).then(function(values) {
+    var katex = values[0], tex = renderer();
 
-      function renderer(options) {
-        return function() {
-          var root = document.createElement("div");
-          katex.render(raw.apply(String, arguments), root, options);
-          return root.removeChild(root.firstChild);
-        };
-      }
+    function renderer(options) {
+      return function() {
+        var root = document.createElement("div");
+        katex.render(raw.apply(String, arguments), root, options);
+        return root.removeChild(root.firstChild);
+      };
+    }
 
-      tex.options = renderer;
-      tex.block = renderer({displayMode: true});
-      return tex;
-    });
-  };
+    tex.options = renderer;
+    tex.block = renderer({displayMode: true});
+    return tex;
+  });
 }

src/vegalite.js

@@ -1,10 +1,8 @@
-export default function vl(require) {
-  return async () => {
-    const [vega, vegalite, api] = await Promise.all([
-      "[email protected]/build/vega.min.js",
-      "[email protected]/build/vega-lite.min.js",
-      "[email protected]/build/vega-lite-api.min.js"
-    ].map(module => require(module)));
-    return api.register(vega, vegalite);
-  };
+export default async function vl(require) {
+  const [vega, vegalite, api] = await Promise.all([
+    "[email protected]/build/vega.min.js",
+    "[email protected]/build/vega-lite.min.js",
+    "[email protected]/build/vega-lite-api.min.js"
+  ].map(module => require(module)));
+  return api.register(vega, vegalite);
 }

test/index-test.js

@@ -11,6 +11,7 @@ test("new Library returns a library with the expected keys", async t => {
     "Mutable",
     "Plot",
     "Promises",
+    "SQLite",
     "_",
     "d3",
     "dot",