first commit

javascript/examples/0_1_magic.js

@@ -0,0 +1,94 @@
+"use strict";
+
+// Magic helper functions
+function example(s, description) {
+    const result = (() => {
+        try {
+            return eval(s);
+        } catch (e) {
+            return e;
+        }
+    })();
+
+    if (description) {
+        println(description + ":", s, "->", result);
+    } else {
+        println(s, "->", result);
+    }
+}
+
+function examples(collection, template) {
+    collection.forEach(function(name) {
+        return example(template.replace('#', name).replace('#', name));
+    });
+}
+
+function subsection(name) {
+    println();
+    println("---", name);
+}
+
+function section(name) {
+    println();
+    println();
+    println("===", name, "===");
+}
+
+function chapter(name) {
+    println();
+    println();
+    println();
+    println("##########", name, "##########");
+}
+
+function lecture(name) {
+    println();
+    println("#".repeat(name.length + 16));
+    println("### Lecture " + name + " ###");
+    println("#".repeat(name.length + 16));
+}
+
+// Helper function
+function dumpProperty(o, property) {
+    if (typeof(o[property]) === "function") {
+        if (o[property].length === 0) {
+            println("    " + property.toString() + "() -> " + o[property]());
+        } else {
+            println("    " + property.toString() + "(...)");
+        }
+    } else {
+        println("    " + property.toString() + " = " + o[property]);
+    }
+}
+
+function dumpObject(name, o) {
+    println(name + ": " + o.constructor.name);
+    for (const property in o) {
+        dumpProperty(o, property);
+    }
+    let symbols = Object.getOwnPropertySymbols(o);
+    if (symbols.length > 0) {
+        for (const property of symbols) {
+            dumpProperty(o, property);
+        }
+    }
+}
+
+function dumpArray(a) {
+    const other = (Object.keys(a)
+        .filter(i => i != "" + parseInt(i) || !(0 <= i && i < a.length))
+        .map(name => name + " = " + a[name])
+        .join(", ")
+    );
+    println("    length: " + a.length + ", elements: [" + a + "]" + (other ? ", other: {" + other + "}" : ""));
+}
+
+if (!String.prototype.repeat) {
+    String.prototype.repeat = function(count) {
+        let result = "";
+        for (let i = 0; i < count; i++) {
+            result += this;
+        }
+        return result;
+    }
+}