From 4590bfd4db6b8e835a3d011789b8f00487d50bc6 Mon Sep 17 00:00:00 2001
From: nebulon42 <nebulon42@mailbox.org>
Date: Sat, 24 Dec 2016 12:58:29 +0100
Subject: [PATCH] let filters accept expressions, ref #121

---
 lib/carto/parser.js              |  3 ++-
 lib/carto/tree/operation.js      |  4 ++++
 test/rendering-mss/issue_121.mss |  3 +++
 test/rendering-mss/issue_121.xml |  6 +++++
 test/rendering/issue_121.mml     | 36 +++++++++++++++++++++++++++++
 test/rendering/issue_121.mss     | 11 +++++++++
 test/rendering/issue_121.result  | 39 ++++++++++++++++++++++++++++++++
 7 files changed, 101 insertions(+), 1 deletion(-)
 create mode 100644 test/rendering-mss/issue_121.mss
 create mode 100644 test/rendering-mss/issue_121.xml
 create mode 100644 test/rendering/issue_121.mml
 create mode 100644 test/rendering/issue_121.mss
 create mode 100644 test/rendering/issue_121.result

diff --git a/lib/carto/parser.js b/lib/carto/parser.js
index 5708ec82b..2943b1727 100644
--- a/lib/carto/parser.js
+++ b/lib/carto/parser.js
@@ -588,7 +588,8 @@ carto.Parser = function Parser(env) {
                         key = new tree.Field(key.toString());
                     }
                     if ((op = $(this.entities.comparison)) &&
-                        (val = $(this.entities.quoted) ||
+                        (val = $(this.expression) ||
+                             $(this.entities.quoted) ||
                              $(this.entities.variable) ||
                              $(this.entities.dimension) ||
                              $(this.entities.keyword) ||
diff --git a/lib/carto/tree/operation.js b/lib/carto/tree/operation.js
index cfacfb3ca..f42ecdfd4 100644
--- a/lib/carto/tree/operation.js
+++ b/lib/carto/tree/operation.js
@@ -84,6 +84,10 @@ tree.Operation.prototype.ev = function(env) {
     return a.operate(env, this.op, b);
 };
 
+tree.Operation.prototype.toString = function () {
+    return this.operands[0].toString() + this.op  + this.operands[1].toString();
+};
+
 tree.operate = function(op, a, b) {
     switch (op) {
         case '+': return a + b;
diff --git a/test/rendering-mss/issue_121.mss b/test/rendering-mss/issue_121.mss
new file mode 100644
index 000000000..6e4bce1b5
--- /dev/null
+++ b/test/rendering-mss/issue_121.mss
@@ -0,0 +1,3 @@
+#data {
+    [[dem] > [rep]] { marker-fill: #00f;}
+}
diff --git a/test/rendering-mss/issue_121.xml b/test/rendering-mss/issue_121.xml
new file mode 100644
index 000000000..1d8e9bb29
--- /dev/null
+++ b/test/rendering-mss/issue_121.xml
@@ -0,0 +1,6 @@
+<Style name="style" filter-mode="first">
+  <Rule>
+    <Filter>([dem] &gt; [rep])</Filter>
+    <MarkersSymbolizer fill="#0000ff" />
+  </Rule>
+</Style>
diff --git a/test/rendering/issue_121.mml b/test/rendering/issue_121.mml
new file mode 100644
index 000000000..3ccdec649
--- /dev/null
+++ b/test/rendering/issue_121.mml
@@ -0,0 +1,36 @@
+{
+  "bounds": [
+    -180,
+    -85.05112877980659,
+    180,
+    85.05112877980659
+  ],
+  "center": [
+    0,
+    0,
+    2
+  ],
+  "format": "png",
+  "interactivity": false,
+  "minzoom": 0,
+  "maxzoom": 22,
+  "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+  "Stylesheet": [
+    "issue_121.mss"
+  ],
+  "Layer": [
+    {
+      "id": "filtertest",
+      "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+      "geometry": "polygon",
+      "Datasource": {
+        "file": "http://mapbox-geodata.s3.amazonaws.com/natural-earth-1.4.0/cultural/10m-admin-0-countries.zip",
+        "type": "shape"
+      }
+    }
+  ],
+  "scale": 1,
+  "metatile": 2,
+  "name": "",
+  "description": ""
+}
diff --git a/test/rendering/issue_121.mss b/test/rendering/issue_121.mss
new file mode 100644
index 000000000..cdc63a013
--- /dev/null
+++ b/test/rendering/issue_121.mss
@@ -0,0 +1,11 @@
+#filtertest[[a] > [b]] {
+    marker-fill: #ff0000;
+}
+
+#filtertest[[a] > [b] * 2] {
+    marker-fill: #00ff00;
+}
+
+#filtertest[[a] > 10 * 2] {
+    marker-fill: #0000ff;
+}
diff --git a/test/rendering/issue_121.result b/test/rendering/issue_121.result
new file mode 100644
index 000000000..e610d9fbc
--- /dev/null
+++ b/test/rendering/issue_121.result
@@ -0,0 +1,39 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE Map[]>
+<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
+
+<Parameters>
+  <Parameter name="bounds">-180,-85.05112877980659,180,85.05112877980659</Parameter>
+  <Parameter name="center">0,0,2</Parameter>
+  <Parameter name="format">png</Parameter>
+  <Parameter name="minzoom">0</Parameter>
+  <Parameter name="maxzoom">22</Parameter>
+  <Parameter name="scale">1</Parameter>
+  <Parameter name="metatile">2</Parameter>
+</Parameters>
+
+
+<Style name="filtertest" filter-mode="first" >
+  <Rule>
+    <Filter>([a] &gt; 20)</Filter>
+    <MarkersSymbolizer fill="#0000ff" />
+  </Rule>
+  <Rule>
+    <Filter>([a] &gt; [b]*2)</Filter>
+    <MarkersSymbolizer fill="#00ff00" />
+  </Rule>
+  <Rule>
+    <Filter>([a] &gt; [b])</Filter>
+    <MarkersSymbolizer fill="#ff0000" />
+  </Rule>
+</Style>
+<Layer name="filtertest"
+  srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
+    <StyleName>filtertest</StyleName>
+    <Datasource>
+       <Parameter name="file">[absolute path]</Parameter>
+       <Parameter name="type"><![CDATA[shape]]></Parameter>
+    </Datasource>
+  </Layer>
+
+</Map>