Add lib/annotate_engine.js

Decouple rules and annotation execution

1 files changed, 43 insertions, 0 deletions

diff --git a/packages/gitbook-markdown/lib/annotate_engine.js b/packages/gitbook-markdown/lib/annotate_engine.js
new file mode 100644
index 0000000..1feea47
--- /dev/null
+++ b/packages/gitbook-markdown/lib/annotate_engine.js
@@ -0,0 +1,43 @@
+function annotateEngine(src, rules, ruleTypes, ruleMap) {
+    var tokens = [];
+
+    while(src) {
+        // Pick rule
+        var rule = ruleTypes.filter(function(ruleName, idx) {
+            var regex = rules[ruleName];
+            return regex.exec(src);
+        })[0];
+
+        // No matching rules
+        if(!rule) {
+            throw new Error('No rule found for: ' + src);
+        }
+
+        // Use rule to extract block
+        var ruleRegex = rules[rule];
+        var block = ruleRegex.exec(src);
+
+        // Get rule type
+        var type = ruleMap[rule] || rule;
+
+        // Get raw text
+        var raw = block[0];
+
+        // Break out here to avoid infinite loops
+        if(raw.length === 0) {
+            break;
+        }
+
+        tokens.push({
+            type: ruleMap[rule] || rule,
+            raw: raw,
+        });
+
+        // Update source
+        src = src.substring(raw.length);
+    }
+
+    return tokens
+}
+
+module.exports = annotateEngine;