Add analytic functions.

* ROW_NUMBER
* RANK
* DENSE_RANK

docs/_includes/side_menu.html

@@ -61,6 +61,7 @@
                   <li><a href="{{ '/reference/cryptographic-hash-functions.html' | relative_url }}">Cryptographic Hash Functions</a></li>
                   <li><a href="{{ '/reference/cast-functions.html' | relative_url }}">Cast Functions</a></li>
                   <li><a href="{{ '/reference/system-functions.html' | relative_url }}">System Functions</a></li>
+                  <li><a href="{{ '/reference/analytic-functions.html' | relative_url }}">Analytic Functions</a></li>
                 </ul>
               </div>
             </li>

docs/_posts/2006-01-02-analytic-functions.md

@@ -0,0 +1,89 @@
+---
+layout: default
+title: Analytic Functions - Reference Manual - csvq
+category: reference
+---
+
+# Analytic Functions
+
+Analytic functions calculate values of groups.
+Analytic Functions can be used only in [Select Clause]({{ '/reference/select-query.html#select_clause' | relative_url }}) and [Order By Clause]({{ '/reference/select-query.html#order_by_clause' | relative_url }})
+
+| name | description |
+| :- | :- |
+| [ROW_NUMBER](#row_number) | Return sequential numbers |
+| [RANK](#rank)             | Return ranks |
+| [DENSE_RANK](#dense_rank) | Return ranks without any gaps in the ranking |
+
+## Syntax
+{: #syntax}
+
+```sql
+analytic_function
+  : function_name([args]) OVER ([partition_clause] [order_by_clause])
+
+args
+  : value [, value ...]
+
+partition_clause
+  : PARTITION BY value [, value ...]
+```
+
+_value_
+: [value]({{ '/reference/value.html' | relative_url }})
+
+_order_by_clause_
+: [Order By Clause]({{ '/reference/select_query.html#order_by_clause' | relative_url }})
+
+Analytic Functions sort the result set by _order_by_clause_ and calculate values within each of groups partitioned by _partition_clause_.
+If there is no _partition_clause_, then all records of result set are dealt with as one group. 
+
+## Definitions
+
+### ROW_NUMBER
+{: #row_number}
+
+```
+ROW_NUMBER() OVER ([partition_clause] [order_by_clause])
+```
+
+_partition_clause_
+: [Partition Clause](#syntax)
+
+_order_by_clause_
+: [Order By Clause]({{ '/reference/select_query.html#order_by_clause' | relative_url }})
+
+Return sequential numbers of records in a group.
+
+
+### RANK
+{: #rank}
+
+```
+RANK() OVER ([partition_clause] [order_by_clause])
+```
+
+_partition_clause_
+: [Partition Clause](#syntax)
+
+_order_by_clause_
+: [Order By Clause]({{ '/reference/select_query.html#order_by_clause' | relative_url }})
+
+Returns ranks of records in a group.
+
+
+### DENSE_RANK
+{: #dense_rank}
+
+```
+DENSE_RANK() OVER ([partition_clause] [order_by_clause])
+```
+
+_partition_clause_
+: [Partition Clause](#syntax)
+
+_order_by_clause_
+: [Order By Clause]({{ '/reference/select_query.html#order_by_clause' | relative_url }})
+
+Returns ranks of records without any gaps in the ranking in a group.
+

docs/_posts/2006-01-02-statement.md

@@ -140,8 +140,8 @@ IF IN INNER INSERT INTERSECT INTO IS
 JOIN
 LAST LEFT LIKE LIMIT
 NATURAL NOT NULL NULLS
-OFFSET ON OPEN OR ORDER OUTER
-PERCENT PRINT
+OFFSET ON OPEN OR ORDER OUTER OVER
+PARTITION PERCENT PRINT
 RENAME RIGHT ROLLBACK
 SELECT SET SEPARATOR STDIN
 TABLE THEN TIES TO

docs/_posts/2006-01-02-value.md

@@ -107,6 +107,7 @@ user.id -- table name and column name
 * [Cryptographic Hash Functions]({{ '/reference/cryptographic-hash-functions.html' | relative_url }})
 * [Cast Functions]({{ '/reference/cast-functions.html' | relative_url }})
 * [System Functions]({{ '/reference/system-functions.html' | relative_url }})
+* [Analytic Functions]({{ '/reference/analytic-functions.html' | relative_url }})
 
 ### Subquery
 {: #subquery}

docs/reference.md

@@ -39,3 +39,4 @@ title: Reference Manual - csvq
   * [Cryptographic Hash Functions]({{ '/reference/cryptographic-hash-functions.html' | relative_url }})
   * [Cast Functions]({{ '/reference/cast-functions.html' | relative_url }})
   * [System Functions]({{ '/reference/system-functions.html' | relative_url }})
+  * [Analytic Functions]({{ '/reference/analytic-functions.html' | relative_url }})

docs/sitemap.xml

@@ -10,7 +10,7 @@
 </url>
 <url>
   <loc>https://mithrandie.github.io/csvq/reference.html</loc>
-  <lastmod>2017-06-29T17:08:49+00:00</lastmod>
+  <lastmod>2017-07-02T23:29:47+00:00</lastmod>
 </url>
 <url>
   <loc>https://mithrandie.github.io/csvq/reference/install.html</loc>
@@ -26,7 +26,7 @@
 </url>
 <url>
   <loc>https://mithrandie.github.io/csvq/reference/value.html</loc>
-  <lastmod>2017-06-29T17:08:49+00:00</lastmod>
+  <lastmod>2017-07-02T23:29:47+00:00</lastmod>
 </url>
 <url>
   <loc>https://mithrandie.github.io/csvq/reference/select-query.html</loc>
@@ -136,6 +136,10 @@
   <loc>https://mithrandie.github.io/csvq/reference/system-functions.html</loc>
   <lastmod>2017-06-29T17:08:49+00:00</lastmod>
 </url>
+<url>
+  <loc>https://mithrandie.github.io/csvq/reference/analytic-functions.html</loc>
+  <lastmod>2017-07-02T23:29:47+00:00</lastmod>
+</url>
 <url>
   <loc>https://mithrandie.github.io/csvq/license.html</loc>
   <lastmod>2017-06-29T17:08:49+00:00</lastmod>

lib/parser/ast.go

@@ -918,14 +918,14 @@ func (si Stdin) String() string {
 }
 
 type OrderItem struct {
-	Item      Expression
+	Value     Expression
 	Direction Token
 	Nulls     string
 	Position  Token
 }
 
 func (e OrderItem) String() string {
-	s := []string{e.Item.String()}
+	s := []string{e.Value.String()}
 	if !e.Direction.IsEmpty() {
 		s = append(s, e.Direction.Literal)
 	}
@@ -1007,6 +1007,68 @@ func (gc GroupConcat) String() string {
 	return gc.GroupConcat + "(" + joinWithSpace(s) + ")"
 }
 
+type AnalyticFunction struct {
+	Name           string
+	Option         Option
+	Over           string
+	AnalyticClause AnalyticClause
+}
+
+func (e AnalyticFunction) String() string {
+	s := []string{
+		e.Name + "(" + e.Option.String() + ")",
+		e.Over,
+		"(" + e.AnalyticClause.String() + ")",
+	}
+	return joinWithSpace(s)
+}
+
+type AnalyticClause struct {
+	Partition     Expression
+	OrderByClause Expression
+}
+
+func (e AnalyticClause) String() string {
+	s := []string{}
+	if e.Partition != nil {
+		s = append(s, e.Partition.String())
+	}
+	if e.OrderByClause != nil {
+		s = append(s, e.OrderByClause.String())
+	}
+	return joinWithSpace(s)
+}
+
+func (e AnalyticClause) PartitionValues() []Expression {
+	if e.Partition == nil {
+		return nil
+	}
+	return e.Partition.(Partition).Values
+}
+
+func (e AnalyticClause) OrderValues() []Expression {
+	if e.OrderByClause == nil {
+		return nil
+	}
+
+	items := e.OrderByClause.(OrderByClause).Items
+	result := make([]Expression, len(items))
+	for i, v := range items {
+		result[i] = v.(OrderItem).Value
+	}
+	return result
+}
+
+type Partition struct {
+	PartitionBy string
+	Values      []Expression
+}
+
+func (e Partition) String() string {
+	s := []string{e.PartitionBy, listExpressions(e.Values)}
+	return joinWithSpace(s)
+}
+
 type Variable struct {
 	Name string
 }