Merge pull request #448 from influxdata/flux-0.43

Flux 0.43

assets/styles/themes/_theme-dark.scss

@@ -86,7 +86,7 @@ $article-note-table-row-alt: #3B2862;
 $article-note-table-scrollbar: $np-deepnight;
 $article-note-shadow: $np-deepnight;
 $article-note-code: $cp-comet;
-$article-note-code-bg: $wp-telopea;
+$article-note-code-bg: $wp-jaguar;
 $article-note-code-accent1: #567375;
 $article-note-code-accent2: $b-pool;
 $article-note-code-accent3: $gr-viridian;

assets/styles/tools/_color-palette.scss

@@ -24,6 +24,7 @@ $g19-ghost:       #FAFAFC;
 $g20-white:       #FFFFFF; // Brand color
 
 // Warm Purples - Magentas
+$wp-jaguar:       #1d0135;
 $wp-telopea:      #23043E;
 $wp-violentdark:  #2d0749;
 $wp-violet:       #32094E;

content/v2.0/reference/flux/language/lexical-elements.md

@@ -294,9 +294,9 @@ StringExpression = "${" Expression "}" .
 ```
 
 String literals are also interpolated for embedded expressions to be evaluated as strings.
-Embedded expressions are enclosed within the literals `${` and `}` respectively.
+Embedded expressions are enclosed in a dollar sign and curly braces (`${}`).
 The expressions are evaluated in the scope containing the string literal.
-The result of an expression is formatted as a string and replaces the string content between the brackets.
+The result of an expression is formatted as a string and replaces the string content between the braces.
 All types are formatted as strings according to their literal representation.
 A function `printf` exists to allow more precise control over formatting of various types.
 To include the literal `${` within a string, it must be escaped.

content/v2.0/reference/flux/language/string-interpolation.md

@@ -0,0 +1,96 @@
+---
+title: String interpolation
+description: >
+  Flux string interpolation evaluates string literals containing one or more placeholders
+  and returns a result with placeholders replaced with their corresponding values.
+menu:
+  v2_0_ref:
+    parent: Flux specification
+    name: String interpolation
+weight: 211
+---
+
+Flux string interpolation evaluates string literals containing one or more placeholders
+and returns a result with placeholders replaced with their corresponding values.
+
+## String interpolation syntax
+To use Flux string interpolation, enclose embedded [expressions](/v2.0/reference/flux/language/expressions/)
+in a dollar sign and curly braces `${}`.
+Flux replaces the content between the braces with the result of the expression and
+returns a string literal.
+
+```js
+name = "John"
+
+"My name is ${name}."
+
+// My name is John.
+```
+
+{{% note %}}
+#### Flux only interpolates string values
+Flux currently interpolates only string values ([IMP#1775](https://github.com/influxdata/flux/issues/1775)).
+Use the [string() function](/v2.0/reference/flux/functions/built-in/transformations/type-conversions/string/)
+to convert non-string values to strings.
+
+```js
+count = 12
+
+"I currently have ${string(v: count)} cats."
+```
+{{% /note %}}
+
+
+## Use dot notation to interpolate object values
+[Objects](/v2.0/reference/flux/language/expressions/#object-literals) consist of key-value pairs.
+Use [dot notation](/v2.0/reference/flux/language/expressions/#member-expressions)
+to interpolate values from an object.
+
+```js
+person = {
+  name: "John",
+  age: 42
+}
+
+"My name is ${person.name} and I'm ${string(v: person.age)} years old."
+
+// My name is John and I'm 42 years old.
+```
+
+Flux returns each record in query results as an object.
+In Flux row functions, each row object is represented by `r`.
+Use dot notation to interpolate specific column values from the `r` object.
+
+##### Use string interpolation to add a human-readable message
+```js
+from(bucket: "example-bucket")
+  |> range(start: -30m)
+  |> map(fn: (r) => ({
+      r with
+      human-readable: "${r._field} is ${r._value} at ${string(v: r._time)}."
+  }))
+```
+
+## String interpolation versus concatenation
+Flux supports both string interpolation and string concatenation.
+String interpolation is a more concise method for achieving the same result.
+
+```js
+person = {
+  name: "John",
+  age: 42
+}
+
+// String interpolation
+"My name is ${person.name} and I'm ${string(v: person.age)} years old."
+
+// String concatenation
+"My name is " + person.name + " and I'm " + string(v: person.age) + " years old."
+
+// Both return: My name is John and I'm 42 years old.
+```
+
+{{% note %}}
+Check and notification message templates configured in the InfluxDB user interface
+**do not** support string concatenation.
+{{% /note %}}

content/v2.0/reference/release-notes/flux.md

@@ -11,13 +11,20 @@ aliases:
 ---
 
 {{% note %}}
-_The latest release of InfluxDB v2.0 alpha includes **Flux v0.42.0**.
+_The latest release of InfluxDB v2.0 alpha includes **Flux v0.43.0**.
 Though newer versions of Flux may be available, they will not be included with
 InfluxDB until the next InfluxDB v2.0 release._
 {{% /note %}}
 
 ---
 
+## v0.43.0 [2019-09-04]
+
+### Features
+- PagerDuty endpoint for alerts and notifications.
+
+---
+
 ## v0.42.0 [2019-08-30]
 
 ### Features