added support for esper style time windows

Author: andykent

lib/grammar.coffee

@@ -36,8 +36,14 @@ grammar =
   ]
 
   SelectClause: [
-    o 'SELECT Fields FROM Literal',                       -> new Select($2, $4, false)
-    o 'SELECT DISTINCT Fields FROM Literal',              -> new Select($3, $5, true)
+    o 'SELECT Fields FROM Table',                         -> new Select($2, $4, false)
+    o 'SELECT DISTINCT Fields FROM Table',                -> new Select($3, $5, true)
+  ]
+  
+  Table: [
+    o 'Literal',                                          -> new Table($1)
+    o 'Literal WINDOW WINDOW_FUNCTION LEFT_PAREN Number RIGHT_PAREN',
+                                                          -> new Table($1, $2, $3, $5)
   ]
 
   WhereClause: [

lib/lexer.coffee

@@ -9,6 +9,7 @@ class Lexer
       bytesConsumed =  @keywordToken() or
                        @starToken() or
                        @functionToken() or
+                       @windowExtension() or
                        @sortOrderToken() or
                        @seperatorToken() or
                        @operatorToken() or
@@ -73,6 +74,13 @@ class Lexer
     @tokenizeFromRegex('LEFT_PAREN', /^\(/,) or 
     @tokenizeFromRegex('RIGHT_PAREN', /^\)/,)
 
+  windowExtension: ->
+    match = (/^\.(win):(length)/i).exec(@chunk)
+    return 0 unless match
+    @token('WINDOW', match[1])
+    @token('WINDOW_FUNCTION', match[2])
+    match[0].length
+  
   whitespaceToken: ->
     return 0 unless match = WHITESPACE.exec(@chunk)
     partMatch = match[0]

lib/nodes.coffee

@@ -44,6 +44,14 @@ exports.Limit = class Limit
   constructor: (@value) -> null
   toString: -> "LIMIT #{@value}"
 
+exports.Table = class Table
+  constructor: (@name, @win=null, @winFn=null, @winArg=null) -> null
+  toString: -> 
+    if @win
+      "#{@name}.#{@win}:#{@winFn}(#{@winArg})"
+    else
+      @name.toString()
+
 exports.Group = class Group
   constructor: (@fields) ->
     @having = null

package.json

@@ -1,7 +1,7 @@
 {
   "name": "sql-parser",
   "description": "Lexer and Parser for SQL Syntax",
-  "version": "0.1.3",
+  "version": "0.1.4",
   "author": {
     "name": "Andy Kent",
     "email": "andy@forward.co.uk"

spec/grammar.spec.coffee

@@ -102,3 +102,9 @@ describe "SQL Grammer", ->
       SELECT LENGTH(`a`)
         FROM `my_table`
       """
+
+    it "supports time window extensions", ->
+      expect(parse("SELECT * FROM my_table.win:length(123)").toString()).toEqual """
+      SELECT *
+        FROM `my_table`.win:length(123)
+      """

spec/lexer.spec.coffee

@@ -26,10 +26,10 @@ describe "SQL Lexer", ->
 # 
 # tokens = lexer.tokenize """
 #   SELECT x AS `first_name`, min(age) 
-#   FROM my_stream
+#   FROM my_stream.win:length(123)
 #   WHERE age > 10.2 AND (age < 30 OR first_name = 'andy')
 #   GROUP BY age, name 
 #   ORDER BY age DESC 
 #   HAVING COUNT(*) > 5"""
-
-console.log(tokens)
+# 
+# console.log(tokens)