From 752661ae6e92bb0514634215b57ecfaae8650c8e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Konstantin=20Ka=CC=88fer?= <mail@kkaefer.com>
Date: Wed, 21 May 2014 10:29:36 +0200
Subject: [PATCH] allow functions to be referenced from constants

fixes #224
---
 bin/style.js               | 26 ++++++++++++++------------
 src/style/style_parser.cpp | 16 +++++++++-------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/bin/style.js b/bin/style.js
index 7760406c5..7318ce377 100644
--- a/bin/style.js
+++ b/bin/style.js
@@ -1359,7 +1359,19 @@ module.exports = {
         "motorway_night": "#eee",
         "main_night": "#95ccdb",
         "street_night": "#0291b5",
-        "contour_night": "#ffff80"
+        "contour_night": "#ffff80",
+
+        "road_main_width": [
+            "stops",
+            {"z": 5, "val": 1},
+            {"z": 12, "val": 1},
+            {"z": 13, "val": 1.5},
+            {"z": 14, "val": 2},
+            {"z": 15, "val": 3},
+            {"z": 16, "val": 6},
+            {"z": 17, "val": 10},
+            {"z": 18, "val": 12}
+        ]
     },
     "classes": [
         {
@@ -1915,17 +1927,7 @@ module.exports = {
                 "road_main": {
                     "transition-color": {"duration": 300},
                     "color": "main",
-                    "width": [
-                        "stops",
-                        {"z": 5, "val": 1},
-                        {"z": 12, "val": 1},
-                        {"z": 13, "val": 1.5},
-                        {"z": 14, "val": 2},
-                        {"z": 15, "val": 3},
-                        {"z": 16, "val": 6},
-                        {"z": 17, "val": 10},
-                        {"z": 18, "val": 12}
-                    ],
+                    "width": "road_main_width",
                     "opacity": [
                         "stops",
                         {"z": 6.5, "val": 0},
diff --git a/src/style/style_parser.cpp b/src/style/style_parser.cpp
index 9972c39ee..06936ded6 100644
--- a/src/style/style_parser.cpp
+++ b/src/style/style_parser.cpp
@@ -391,16 +391,18 @@ FunctionProperty::fn StyleParser::parseFunctionType(JSVal type) {
 }
 
 FunctionProperty StyleParser::parseFunction(JSVal value) {
+    JSVal rvalue = replaceConstant(value);
+
     FunctionProperty property;
 
-    if (value.IsArray()) {
-        if (value.Size() < 1) {
+    if (rvalue.IsArray()) {
+        if (rvalue.Size() < 1) {
             throw Style::exception("value function does not have arguments");
         }
 
-        property.function = parseFunctionType(value[(rapidjson::SizeType)0]);
-        for (rapidjson::SizeType i = 1; i < value.Size(); ++i) {
-            JSVal stop = value[i];
+        property.function = parseFunctionType(rvalue[(rapidjson::SizeType)0]);
+        for (rapidjson::SizeType i = 1; i < rvalue.Size(); ++i) {
+            JSVal stop = rvalue[i];
             if (stop.IsObject()) {
                 if (!stop.HasMember("z")) {
                     throw Style::exception("stop must have zoom level specification");
@@ -427,9 +429,9 @@ FunctionProperty StyleParser::parseFunction(JSVal value) {
                 throw Style::exception("function argument must be a numeric value");
             }
         }
-    } else if (value.IsNumber()) {
+    } else if (rvalue.IsNumber()) {
         property.function = &functions::constant;
-        property.values.push_back(value.GetDouble());
+        property.values.push_back(rvalue.GetDouble());
     }
 
     return property;