From bbabf59505266c1038916ad65d3f856fb8959d25 Mon Sep 17 00:00:00 2001
From: Ian Gulliver <ian@isinglasstheater.org>
Date: Tue, 20 May 2014 12:49:30 -0700
Subject: [PATCH] Start of an actual parser.

---
 recentrunes.js | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
 test.js        | 10 +++++++
 2 files changed, 88 insertions(+)

diff --git a/recentrunes.js b/recentrunes.js
index 27eb41a..6d78900 100644
--- a/recentrunes.js
+++ b/recentrunes.js
@@ -1,6 +1,24 @@
 var rr = {};
 
 rr.Literal_ = function(value) {
+  this.value_ = value;
+};
+
+rr.Literal_.prototype.match = function(input) {
+  if (input.slice(0, this.value_.length) == this.value_) {
+    return [this.value_.length, null];
+  } else {
+    return null;
+  }
+};
+
+rr.Literal_.prototype.search = function(input) {
+  var index = input.indexOf(this.value_);
+  if (index == -1) {
+    return null;
+  } else {
+    return index;
+  }
 };
 
 rr.Literal = function(value) {
@@ -11,6 +29,7 @@ rr.Literal.cache = {};
 
 
 rr.Ref_ = function(key) {
+  this.key_ = key;
 };
 
 rr.Ref = function(key) {
@@ -32,6 +51,8 @@ rr.EndOfLine.cache = new rr.EndOfLine_();
 rr.MultiLineText_ = function() {
 };
 
+rr.MultiLineText_.prototype.minimize = true;
+
 rr.MultiLineText = function() {
   return rr.MultiLineText.cache;
 };
@@ -39,6 +60,7 @@ rr.MultiLineText.cache = new rr.MultiLineText_();
 
 
 rr.Or_ = function(options) {
+  this.options_ = options;
 };
 
 rr.Or = function() {
@@ -49,6 +71,17 @@ rr.Or = function() {
 rr.SingleLineText_ = function() {
 };
 
+rr.SingleLineText_.prototype.minimize = true;
+
+rr.SingleLineText_.prototype.match = function(input) {
+  var newLine = input.indexOf('\n');
+  if (newLine == -1) {
+    return [input.length, document.createTextNode(input)];
+  } else {
+    return [newLine, document.createTextNode(input.slice(0, newLine))];
+  }
+};
+
 rr.SingleLineText = function() {
   return rr.SingleLineText.cache;
 };
@@ -67,6 +100,8 @@ rr.StartOfLine.cache = new rr.StartOfLine_();
 rr.WordText_ = function() {
 };
 
+rr.WordText_.prototype.minimize = true;
+
 rr.WordText = function() {
   return rr.WordText.cache;
 };
@@ -74,6 +109,7 @@ rr.WordText.cache = new rr.WordText_();
 
 
 rr.ZeroOrMore_ = function(key) {
+  this.key_ = key;
 };
 
 rr.ZeroOrMore = function(key) {
@@ -88,4 +124,46 @@ var RecentRunes = function(dictionary) {
 };
 
 RecentRunes.prototype.parse = function(nodeType, input) {
+  var ret = document.createElement(nodeType);
+  var rules = this.dictionary_[nodeType];
+  var inputIndex = 0;
+  var lastRuleMinimize = false;
+  for (var i = 0; i < rules.length; i++) {
+    var rule = rules[i];
+    if (rule.minimize) {
+      if (lastRuleMinimize) {
+        // Two minimize rules in a row is ambiguous
+        return null;
+      }
+      lastRuleMinimize = true;
+      continue;
+    }
+    if (lastRuleMinimize) {
+      // Check if this rule can find a match in the string
+      var loc = rule.search(input.slice(inputIndex));
+      if (loc == null) {
+        return null;
+      }
+
+      // Check if the previous rule will match the interim data
+      var prevMatch = rules[i - 1].match(
+          input.slice(inputIndex, inputIndex + loc));
+      if (!prevMatch) {
+        return null;
+      };
+      inputIndex += prevMatch[0];
+      if (prevMatch[1]) {
+        ret.appendChild(prevMatch[1]);
+      }
+    }
+    var match = rule.match(input.slice(inputIndex));
+    if (!match) {
+      return null;
+    }
+    inputIndex += match[0];
+    if (match[1]) {
+      ret.appendChild(match[1]);
+    }
+  };
+  return [inputIndex, ret];
 };
diff --git a/test.js b/test.js
index e69de29..6b664d2 100644
--- a/test.js
+++ b/test.js
@@ -0,0 +1,10 @@
+test('Simple', function() {
+  expect(0);
+  var grammar = {
+    'rule1': [rr.Literal('=== '), rr.SingleLineText(), rr.Literal(' ===')],
+    'rule2': [rr.SingleLineText(), rr.Literal('=')],
+  };
+  var parser = new RecentRunes(grammar);
+  console.log(parser.parse('rule1', '=== bar ==='));
+  console.log(parser.parse('rule2', 'foo=\nbar='));
+});