Simplify Path and Sexpr calculated flags

1 files changed, 36 insertions, 4 deletions

diff --git a/lib/handlebars/compiler/compiler.js b/lib/handlebars/compiler/compiler.js
index ea65583..5dbbfc4 100644
--- a/lib/handlebars/compiler/compiler.js
+++ b/lib/handlebars/compiler/compiler.js
@@ -3,6 +3,26 @@ import {isArray} from "../utils";
 
 var slice = [].slice;
 
+
+// a mustache is definitely a helper if:
+// * it is an eligible helper, and
+// * it has at least one parameter or hash segment
+function helperExpr(sexpr) {
+  return !!(sexpr.isHelper || sexpr.params.length || sexpr.hash);
+}
+
+function scopedId(id) {
+  return (/^\.|this\b/).test(id.original);
+}
+
+// an ID is simple if it only has one part, and that part is not
+// `..` or `this`.
+function simpleId(id) {
+  var part = id.parts[0];
+
+  return id.parts.length === 1 && !scopedId(id) && !id.depth;
+}
+
 export function Compiler() {}
 
 // the foundHelper register will disambiguate helper lookup from finding a
@@ -245,7 +265,7 @@ Compiler.prototype = {
       id.falsy = true;
 
       this.accept(id);
-      this.opcode('invokeHelper', sexpr, params.length, id.original, id.isSimple);
+      this.opcode('invokeHelper', sexpr, params.length, id.original, simpleId(id));
     }
   },
 
@@ -275,7 +295,7 @@ Compiler.prototype = {
       this.options.data = true;
       this.opcode('lookupData', id, id.depth, id.parts);
     } else {
-      this.opcode('lookupOnContext', id, id.parts, id.falsy, id.isScoped);
+      this.opcode('lookupOnContext', id, id.parts, id.falsy, scopedId(id));
     }
   },
 
@@ -306,8 +326,15 @@ Compiler.prototype = {
   },
 
   classifySexpr: function(sexpr) {
-    var isHelper   = sexpr.isHelper;
-    var isEligible = sexpr.eligibleHelper;
+    // a mustache is an eligible helper if:
+    // * its id is simple (a single part, not `this` or `..`)
+    var isHelper   = helperExpr(sexpr);
+
+    // if a mustache is an eligible helper but not a definite
+    // helper, it is ambiguous, and will be resolved in a later
+    // pass or at runtime.
+    var isEligible = isHelper || simpleId(sexpr.id);
+
     var options    = this.options;
 
     // if ambiguous, we can possibly resolve the ambiguity now
@@ -336,6 +363,11 @@ Compiler.prototype = {
   pushParam: function(val) {
     var value = val.value != null ? val.value : val.original || '';
 
+    // Force helper evaluation
+    if (val.type === 'sexpr') {
+      val.isHelper = true;
+    }
+
     if (this.stringParams) {
       if (value.replace) {
         value = value