Initial commit

7 files changed, 325 insertions, 0 deletions

diff --git a/lib/binops.js b/lib/binops.js
new file mode 100644
index 0000000..a709097
--- /dev/null
+++ b/lib/binops.js
@@ -0,0 +1,33 @@
+var binaryOperators = {
+	'!=': function(a, b) {
+		return a != b;
+	},
+
+	'<': function(a, b) {
+		return a < b;
+	},
+
+	'>': function(a, b) {
+		return a > b;
+	},
+
+	'-': function(a, b) {
+		return a - b;
+	},
+
+	'+': function(a, b) {
+		return a + b;
+	},
+
+	'==': function(a, b) {
+		return a == b;
+	},
+
+	'<=': function(a, b) {
+		return a <= b;
+	},
+
+	'>=': function(a, b) {
+		return a >= b;
+	}
+};
diff --git a/lib/readability.js b/lib/readability.js
new file mode 100644
index 0000000..06eb4ad
--- /dev/null
+++ b/lib/readability.js
@@ -0,0 +1,38 @@
+var appendText = function(node, text) {
+	var n = document.createElement('var');
+	n.innerText = text;
+	node.appendChild(n);
+};
+
+var readability = {
+	'assign': function(e) {
+		return e.dataset.name;
+	},
+
+	'variable': function(e) {
+		return e.dataset.name;
+	},
+
+	'constant': function(e) {
+		return e.dataset.type + '(' + e.dataset.val + ')';
+	},
+
+	'compare': function(e) {
+		return e.dataset.op;
+	},
+
+	'bin-op': function(e) {
+		return e.dataset.op;
+	}
+};
+
+var makeReadable = function(root) {
+	var classes = Object.keys(readability);
+	for (var idx = 0; idx < classes.length; idx++) {
+		var klass = classes[idx];
+		var els = root.getElementsByClassName(klass);
+		els.forEach(function(el) {
+			appendText(el, readability[klass](el));
+		});
+	}
+};
diff --git a/lib/run.js b/lib/run.js
new file mode 100644
index 0000000..92441a2
--- /dev/null
+++ b/lib/run.js
@@ -0,0 +1,20 @@
+(function() {
+	var evaluate = function(node, context) {
+		if (typeof context === 'undefined') {
+			context = {};
+		}
+		return statementEvaluators[node.className](node.dataset, node.children, context);
+	};
+
+	var statementEvaluators = getStatementEvaluators(evaluate);
+
+	document.addEventListener('DOMContentLoaded', function() {
+		var t0 = performance.now();
+		evaluate(document.body.children[0]);
+		var t1 = performance.now();
+		makeReadable(document.body);
+		var t2 = performance.now();
+		console.debug('Evaluated in ' + (t1 - t0) + 'ms');
+		console.debug('Rendered in ' + (t2 - t1) + 'ms');
+	});
+})();
diff --git a/lib/statements.js b/lib/statements.js
new file mode 100644
index 0000000..b59c08f
--- /dev/null
+++ b/lib/statements.js
@@ -0,0 +1,74 @@
+var getStatementEvaluators = function(evaluate) {
+	return {
+		'statement-sequence': function(dataset, children, context) {
+			var retval = null;
+			children.forEach(function(child) {
+				retval = evaluate(child, context);
+			});
+			return retval;
+		},
+
+		'while': function(dataset, children, context) {
+			var condition = children[0];
+			var body = children[1];
+			while (evaluate(condition, context)) {
+				evaluate(body, context);
+			}
+		},
+
+		'compare': function(dataset, children, context) {
+			var operator = binaryOperators[dataset.op];
+			var lhs = evaluate(children[0], context);
+			var rhs = evaluate(children[1], context);
+			var result = operator(lhs, rhs);
+			return result;
+		},
+
+		'variable': function(dataset, children, context) {
+			return context[dataset.name];
+		},
+
+		'constant': function(dataset, children, context) {
+			return stringToType(dataset.val, dataset.type);
+		},
+
+		'branch': function(dataset, children, context) {
+			var condition = children[0];
+			var ifBody = children[1];
+
+			// else is optional
+			if (children.length > 2) {
+				var elseBody = children[2];
+			}
+
+			if (evaluate(condition, context)) {
+				return evaluate(ifBody, context);
+			} else if (elseBody) {
+				return evaluate(elseBody, context);
+			}
+		},
+
+		'assign': function(dataset, children, context) {
+			context[dataset.name] = evaluate(children[0], context);
+			return context[dataset.name];
+		},
+
+		'bin-op': function(dataset, children, context) {
+			var operator = binaryOperators[dataset.op];
+			var lhs = evaluate(children[0], context);
+			var rhs = evaluate(children[1], context);
+			return operator(lhs, rhs);
+		},
+
+		'return': function(dataset, children, context) {
+			return evaluate(children[0], context);
+		},
+
+		'print': function(dataset, children, context) {
+			var args = children.map(function(child) {
+				return evaluate(child, context);
+			});
+			console.log.apply(this, args);
+		}
+	};
+};
diff --git a/lib/style.css b/lib/style.css
new file mode 100644
index 0000000..6b7d25f
--- /dev/null
+++ b/lib/style.css
@@ -0,0 +1,125 @@
+body {
+	font-family: monospace;
+}
+
+span {
+	display: flex;
+	padding-left: 3px;
+	padding-right: 3px;
+}
+
+var {
+	font-style: normal;
+	padding-left: 3px;
+	padding-right: 3px;
+}
+
+.statement-sequence {
+	display: block;
+	border: 2px solid #666;
+}
+
+.statement-sequence > span {
+	background-color: yellow;
+	padding: 3px;
+	margin: 3px;
+	border: 1px dotted #666;
+}
+
+.assign {
+	color: blue;
+}
+
+.assign::before {
+	content: 'Variable Assignment';
+	color: darkmagenta;
+	order: 1;
+}
+
+.assign::after {
+	content: '=';
+	color: black;
+	order: 3;
+}
+
+.assign > *:nth-child(1) {
+	order: 4;
+}
+
+.assign > *:nth-child(2) {
+	order: 2;
+}
+
+.variable {
+	color: blue;
+}
+
+.constant {
+	color: red;
+}
+
+.while {
+	flex-direction: column;
+}
+
+.while > span {
+	margin-left: 20px;
+}
+
+.while::before {
+	content: 'While';
+	color: darkmagenta;
+}
+
+.return > span {
+	order: 2;
+}
+
+.return::after {
+	content: 'Return';
+	color: darkmagenta;
+	order: 1;
+}
+
+.compare::before {
+	content: 'Comparison';
+	color: darkmagenta;
+	order: 1;
+}
+
+.compare > *:nth-child(1) {
+	order: 2;
+}
+
+.compare > *:nth-child(3) {
+	order: 3;
+}
+
+.compare > *:nth-child(2) {
+	order: 4;
+}
+
+.branch {
+	flex-direction: column;
+}
+
+.branch::before {
+	content: 'Logical Branch';
+	color: darkmagenta;
+}
+
+.branch > span {
+	margin-left: 20px;
+}
+
+.bin-op > span:nth-child(1) {
+	order: 1;
+}
+
+.bin-op > span:nth-child(2) {
+	order: 3;
+}
+
+.bin-op > var {
+	order: 2;
+}
diff --git a/lib/types.js b/lib/types.js
new file mode 100644
index 0000000..38e2b60
--- /dev/null
+++ b/lib/types.js
@@ -0,0 +1,22 @@
+var stringToType = function(str, type) {
+	switch (type) {
+		case 'number':
+			if (str.indexOf('.')) {
+				return parseFloat(str);
+			} else {
+				return parseInt(str, 10);
+			}
+		case 'string':
+			return str;
+		case 'boolean':
+			if (str === 'true') {
+				return true;
+			} else if (str === 'false') {
+				return false;
+			} else {
+				throw new Error('Invalid boolean value ' + str);
+			}
+		default:
+			throw new Error('type', type, 'is not defined');
+	}
+};
diff --git a/lib/util.js b/lib/util.js
new file mode 100644
index 0000000..3c6857c
--- /dev/null
+++ b/lib/util.js
@@ -0,0 +1,13 @@
+HTMLCollection.prototype.map = function(fn) {
+	var results = [];
+	for (var idx = 0; idx < this.length; idx++) {
+		results.push(fn(this.item(idx)));
+	}
+	return results;
+};
+
+HTMLCollection.prototype.forEach = function(fn) {
+	for (var idx = 0; idx < this.length; idx++) {
+		fn(this.item(idx));
+	}
+};