state machine

Author: goto-bus-stop

find-fast.js

@@ -1,5 +1,6 @@
 var acorn = require('acorn');
 var defined = require('defined');
+var nanostate = require('nanostate');
 
 var ST_NONE = 0;
 var ST_SAW_NAME = 1;
@@ -11,9 +12,26 @@ module.exports = function findFast(src, opts) {
     if (typeof src !== 'string') src = String(src);
     if (opts.word === undefined) opts.word = 'require';
 
+    var machine = nanostate('none', {
+        none: {
+            name: 'sawName',
+            dot: 'memberExpression',
+            reset: 'none'
+        },
+        sawName: {
+            parenL: 'insideCall',
+            dot: 'memberExpression',
+            reset: 'none'
+        },
+        insideCall: {
+            parenR: 'none',
+            reset: 'none'
+        },
+        memberExpression: { reset: 'none' }
+    });
+
     var tokenizer = acorn.tokenizer(src, opts.parse);
     var token;
-    var state = ST_NONE;
 
     var opener;
     var args = [];
@@ -22,15 +40,15 @@ module.exports = function findFast(src, opts) {
     if (opts.nodes) modules.nodes = [];
 
     while ((token = tokenizer.getToken()) && token.type !== acorn.tokTypes.eof) {
-        if (state !== ST_INSIDE_CALL && token.type === acorn.tokTypes.dot) {
-            state = ST_MEMBER_EXPRESSION;
-        } else if (state === ST_NONE && token.type === acorn.tokTypes.name && mayBeRequire(token)) {
-            state = ST_SAW_NAME;
+        if (machine.state !== 'insideCall' && token.type === acorn.tokTypes.dot) {
+            machine.emit('dot')
+        } else if (machine.state === 'none' && token.type === acorn.tokTypes.name && mayBeRequire(token)) {
             opener = token;
-        } else if (state === ST_SAW_NAME && token.type === acorn.tokTypes.parenL) {
-            state = ST_INSIDE_CALL;
+            machine.emit('name')
+        } else if (machine.state === 'sawName' && token.type === acorn.tokTypes.parenL) {
             args = [];
-        } else if (state === ST_INSIDE_CALL) {
+            machine.emit('parenL')
+        } else if (machine.state === 'insideCall') {
             if (token.type === acorn.tokTypes.parenR) { // End of fn() call
                 if (args.length === 1 && args[0].type === acorn.tokTypes.string) {
                     modules.strings.push(args[0].value);
@@ -46,12 +64,12 @@ module.exports = function findFast(src, opts) {
                     modules.nodes.push(node);
                 }
 
-                state = ST_NONE;
+                machine.emit('parenR')
             } else {
                 args.push(token);
             }
         } else {
-            state = ST_NONE;
+            machine.emit('reset');
         }
     }
     return modules;

package.json

@@ -19,6 +19,7 @@
   "dependencies": {
     "acorn": "^4.0.3",
     "defined": "^1.0.0",
+    "nanostate": "^1.0.3",
     "shallow-copy": "0.0.1"
   },
   "devDependencies": {