Merge pull request #15 from carocad/perf

Performance improvements

.travis.yml

@@ -18,10 +18,10 @@ jobs:
         - lein trampoline test
         - nvm install 10.10 && nvm use 10.10 && lein trampoline cljsbuild test
 
-    # only run the benchmark is we are on master
+    # only run the benchmark if we are trying to merge to master
     # otherwise the build takes too long
     - stage: Benchmark
-      if: head_branch = master
+      if: branch = master
       script:
         - lein trampoline test :benchmark
 

README.md

@@ -32,20 +32,29 @@ full explanation of the options available for a parser please visit Instaparse w
   [:symbol "parcera.core"]
   [:whitespace " "]
   [:list
-   [:simple-keyword "require"]
+   [:simple-keyword ":require"]
    [:whitespace " "]
    [:vector
     [:symbol "instaparse.core"]
     [:whitespace " "]
-    [:simple-keyword "as"]
+    [:simple-keyword ":as"]
     [:whitespace " "]
     [:symbol "instaparse"]]
    [:whitespace " "]
-   [:vector [:symbol "clojure.data"] [:whitespace " "] [:simple-keyword "as"] [:whitespace " "] [:symbol "data"]]
+   [:vector [:symbol "clojure.data"] [:whitespace " "] [:simple-keyword ":as"] [:whitespace " "] [:symbol "data"]]
    [:whitespace " "]
-   [:vector [:symbol "clojure.string"] [:whitespace " "] [:simple-keyword "as"] [:whitespace " "] [:symbol "str"]]]]]
+   [:vector [:symbol "clojure.string"] [:whitespace " "] [:simple-keyword ":as"] [:whitespace " "] [:symbol "str"]]]]]
 
 ;; convert an AST back into a string
 (parcera/code [:symbol "ns"])
 ;; "ns"
 ```
+
+### notes
+There are some restrictions as to how much can a parser do. In my experience, these restrictions
+are related to some [semantic context-sensitivity](http://blog.reverberate.org/2013/09/ll-and-lr-in-context-why-parsing-tools.html).
+which the Clojure reader has embedded into itself. In general I have found the following ones:
+    - `parcera` doesnt check that a map contains an even number of elements. This is specially difficult
+      to do since Clojure supports the discard macro `#_ form` which is a valid element but "doesnt count as one"
+    - `parcera` doesnt check if a map has repeated keys
+    - `parcera` doesnt check if a set has repeated elements

project.clj

@@ -1,4 +1,4 @@
-(defproject carocad/parcera "0.2.1"
+(defproject carocad/parcera "0.3.0"
   :description "Grammar-based Clojure(script) parser"
   :url "https://github.com/carocad/parcera"
   :license {:name "LGPLv3"