From 2f70f7944c9998d8ee9aadd0baf6a4ad0bb67aad Mon Sep 17 00:00:00 2001
From: erikolson186 <erikolson186@gmail.com>
Date: Wed, 14 Jun 2017 20:48:22 -0400
Subject: [PATCH 1/3] Attempt to fix sort and limit bug

https://github.com/erikolson186/zangodb/issues/9
---
 src/create_next_fn.js | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/create_next_fn.js b/src/create_next_fn.js
index 15327a1..be37d63 100644
--- a/src/create_next_fn.js
+++ b/src/create_next_fn.js
@@ -2,7 +2,8 @@ const merge = require('deepmerge');
 
 const { hashify, getIDBError } = require('./util.js'),
       filter = require('./filter.js'),
-      sort = require('./sort.js');
+      sort = require('./sort.js'),
+      limit = require('./limit.js');
 
 const {
     build,
@@ -77,13 +78,15 @@ const buildPredicates = (pipeline) => {
 const initPredAndSortSpec = (config) => {
     const { pipeline } = config,
           preds = [],
-          sort_specs = [];
+          sort_specs = [],
+          limits = [];
 
     let i = 0;
 
     for (let [fn, arg] of pipeline) {
         if (fn === sort) { sort_specs.push(arg); }
         else if (fn === filter) { preds.push(arg); }
+        else if (fn === limit) { limits.push(arg); }
         else { break; }
 
         i++;
@@ -92,10 +95,14 @@ const initPredAndSortSpec = (config) => {
     pipeline.splice(0, i);
 
     config.pred = joinPredicates(preds);
-
+    
     if (sort_specs.length) {
         config.sort_spec = sort_specs.reduce(merge, {});
     }
+
+    if (limits.length) {
+        config.limit_num = limits.reduce((a, b) => a + b);
+    }
 };
 
 const getClauses = (col, pred) => {
@@ -165,6 +172,14 @@ const initSort = (config) => {
     }
 };
 
+const initLimit = (config) => {
+    if (config.limit_num === undefined) { return; }
+
+    const { limit_num, pipeline } = config;
+    
+    pipeline.push([limit, limit_num]);
+};
+
 const createGetIDBReqFn = ({ pred, clauses, pipeline }) => {
     let getIDBReq;
 
@@ -325,6 +340,7 @@ module.exports = (cur) => {
         initClauses(config);
         initHint(config);
         initSort(config);
+        initLimit(config);
 
         next = createNextFn(config);
     }

From 8d5aad8b1a8d00d9620f569eabe6a1181eced08b Mon Sep 17 00:00:00 2001
From: erikolson186 <erikolson186@gmail.com>
Date: Wed, 14 Jun 2017 21:10:36 -0400
Subject: [PATCH 2/3] Remove initPredAndSortSpec and modify initLimit

---
 src/create_next_fn.js | 65 ++++++++++++++++++++-----------------------
 1 file changed, 30 insertions(+), 35 deletions(-)

diff --git a/src/create_next_fn.js b/src/create_next_fn.js
index be37d63..72b1291 100644
--- a/src/create_next_fn.js
+++ b/src/create_next_fn.js
@@ -75,36 +75,6 @@ const buildPredicates = (pipeline) => {
     return new_pipeline;
 };
 
-const initPredAndSortSpec = (config) => {
-    const { pipeline } = config,
-          preds = [],
-          sort_specs = [],
-          limits = [];
-
-    let i = 0;
-
-    for (let [fn, arg] of pipeline) {
-        if (fn === sort) { sort_specs.push(arg); }
-        else if (fn === filter) { preds.push(arg); }
-        else if (fn === limit) { limits.push(arg); }
-        else { break; }
-
-        i++;
-    }
-
-    pipeline.splice(0, i);
-
-    config.pred = joinPredicates(preds);
-    
-    if (sort_specs.length) {
-        config.sort_spec = sort_specs.reduce(merge, {});
-    }
-
-    if (limits.length) {
-        config.limit_num = limits.reduce((a, b) => a + b);
-    }
-};
-
 const getClauses = (col, pred) => {
     if (!pred) { return []; }
 
@@ -173,11 +143,11 @@ const initSort = (config) => {
 };
 
 const initLimit = (config) => {
-    if (config.limit_num === undefined) { return; }
-
     const { limit_num, pipeline } = config;
-    
-    pipeline.push([limit, limit_num]);
+
+    if (config.hasOwnProperty('limit_num')) {
+        pipeline.push([limit, limit_num]);
+    }
 };
 
 const createGetIDBReqFn = ({ pred, clauses, pipeline }) => {
@@ -330,7 +300,32 @@ module.exports = (cur) => {
         pipeline
     };
 
-    initPredAndSortSpec(config);
+    const preds = [],
+          sort_specs = [],
+          limits = [];
+
+    let i = 0;
+
+    for (let [fn, arg] of pipeline) {
+        if (fn === sort) { sort_specs.push(arg); }
+        else if (fn === filter) { preds.push(arg); }
+        else if (fn === limit) { limits.push(arg); }
+        else { break; }
+
+        i++;
+    }
+
+    pipeline.splice(0, i);
+
+    config.pred = joinPredicates(preds);
+
+    if (sort_specs.length) {
+        config.sort_spec = sort_specs.reduce(merge, {});
+    }
+
+    if (limits.length) {
+        config.limit_num = limits.reduce((a, b) => a + b);
+    }
 
     let next;
 

From 4726ff1aeef81bca582b106d6dfe151710cc44d1 Mon Sep 17 00:00:00 2001
From: erikolson186 <erikolson186@gmail.com>
Date: Thu, 15 Jun 2017 18:05:48 -0400
Subject: [PATCH 3/3] Use unshift for adding sort to pipeline

---
 src/create_next_fn.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/create_next_fn.js b/src/create_next_fn.js
index 72b1291..5a79486 100644
--- a/src/create_next_fn.js
+++ b/src/create_next_fn.js
@@ -138,7 +138,7 @@ const initSort = (config) => {
     if (new_clauses.length) {
         config.clauses = new_clauses;
     } else {
-        pipeline.push([sort, spec]);
+        pipeline.unshift([sort, spec]);
     }
 };
 
@@ -267,7 +267,7 @@ const createParallelNextFn = (config) => {
     };
 
     const spec = config.sort_spec;
-    if (spec) { config.pipeline.push([sort, spec]); }
+    if (spec) { config.pipeline.unshift([sort, spec]); }
 
     return next;
 };
@@ -339,6 +339,6 @@ module.exports = (cur) => {
 
         next = createNextFn(config);
     }
-
+    
     return addPipelineStages(config, next);
 };