added PI() function

Documentation/Books/AQL/Functions/Numeric.mdpp

@@ -309,6 +309,18 @@ PERCENTILE( [1, 2, 3, 4], 50, "rank" ) // 2
 PERCENTILE( [1, 2, 3, 4], 50, "interpolation" ) // 2.5
 ```
 
+!SUBSECTION PI()
+
+`PI() → pi`
+
+Return pi.
+
+- returns **pi** (number): the first few significant digits of pi (3.141592653589793)
+
+```js
+PI() // 3.141592653589793
+```
+
 !SUBSECTION POW()
 
 `POW(base, exp) → num`

arangod/Aql/FunctionDefinitions.cpp

@@ -230,6 +230,8 @@ struct FunctionDefiner {
                       &Functions::Radians});
     add({"DEGREES", "AQL_DEGREES", "n", true, true, false, true, true,
                       &Functions::Degrees});
+    add({"PI", "AQL_PI", "", true, true, false, true, true,
+                      &Functions::Pi});
   }
 
   void addListFunctions() { 

arangod/Aql/Functions.cpp

@@ -3242,6 +3242,16 @@ AqlValue Functions::Degrees(arangodb::aql::Query* query,
   return NumberValue(trx, radians * (180.0 / std::acos(-1.0)), true);
 }
 
+/// @brief function PI
+AqlValue Functions::Pi(arangodb::aql::Query* query,
+                       arangodb::AqlTransaction* trx,
+                       VPackFunctionParameters const& parameters) {
+  ValidateParameters(parameters, "PI", 0, 0);
+  
+  // acos(-1) == PI
+  return NumberValue(trx, std::acos(-1.0), true);
+}
+
 /// @brief function RAND
 AqlValue Functions::Rand(arangodb::aql::Query* query,
                          arangodb::AqlTransaction* trx,

arangod/Aql/Functions.h

@@ -209,6 +209,8 @@ struct Functions {
                           VPackFunctionParameters const&);
   static AqlValue Degrees(arangodb::aql::Query*, arangodb::AqlTransaction*,
                           VPackFunctionParameters const&);
+  static AqlValue Pi(arangodb::aql::Query*, arangodb::AqlTransaction*,
+                     VPackFunctionParameters const&);
   static AqlValue Rand(arangodb::aql::Query*, arangodb::AqlTransaction*,
                        VPackFunctionParameters const&);
   static AqlValue FirstDocument(arangodb::aql::Query*,

js/apps/system/_admin/aardvark/APP/frontend/src/mode-aql.js

@@ -94,7 +94,7 @@ var AqlHighlightRules = function() {
     var builtinFunctions = (
         "(to_bool|to_number|to_string|to_list|is_null|is_bool|is_number|is_string|is_list|is_document|typename|" +
         "concat|concat_separator|char_length|lower|upper|substring|left|right|trim|reverse|contains|" +
-        "log|log2|log10|exp|exp2|sin|cos|tan|asin|acos|atan|atan2|radians|degrees|regex|" +
+        "log|log2|log10|exp|exp2|sin|cos|tan|asin|acos|atan|atan2|radians|degrees|pi|regex|" +
         "like|floor|ceil|round|abs|rand|sqrt|pow|length|min|max|average|sum|median|variance_population|" +
         "variance_sample|first|last|unique|matches|merge|merge_recursive|has|attributes|values|unset|unset_recursive|keep|" +
         "near|within|within_rectangle|is_in_polygon|fulltext|paths|traversal|traversal_tree|edges|stddev_sample|stddev_population|" +

js/server/modules/@arangodb/aql.js

@@ -3105,6 +3105,16 @@ function AQL_DEGREES (value) {
   return NUMERIC_VALUE(value * (180 / Math.PI));
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief pi
+////////////////////////////////////////////////////////////////////////////////
+
+function AQL_PI () {
+  'use strict';
+
+  return Math.PI;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief get the length of a list, document or string
 ////////////////////////////////////////////////////////////////////////////////
@@ -8399,6 +8409,7 @@ exports.AQL_ATAN = AQL_ATAN;
 exports.AQL_ATAN2 = AQL_ATAN2;
 exports.AQL_RADIANS = AQL_RADIANS;
 exports.AQL_DEGREES = AQL_DEGREES;
+exports.AQL_PI = AQL_PI;
 exports.AQL_LENGTH = AQL_LENGTH;
 exports.AQL_FIRST = AQL_FIRST;
 exports.AQL_LAST = AQL_LAST;

js/server/tests/aql/aql-functions-numeric.js

@@ -51,6 +51,23 @@ function ahuacatlNumericFunctionsTestSuite () {
 
   return {
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test pi function
+////////////////////////////////////////////////////////////////////////////////
+    
+    testPi : function () {
+      var expected = 3.141592653589793;
+      
+      var query = "RETURN PI()";
+      assertAlmostEqual(expected, getQueryResults(query)[0]);
+      
+      query = "RETURN NOOPT(PI())";
+      assertAlmostEqual(expected, getQueryResults(query)[0]);
+        
+      query = "RETURN NOOPT(V8(PI()))";
+      assertAlmostEqual(expected, getQueryResults(query)[0]);
+    },
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief test log function
 ////////////////////////////////////////////////////////////////////////////////