Install aftermarket expression functions (#11472)

* [ios, macos] Introduced more ergonomic expression concatenation syntax

* [ios, macos] Fixed mgl_join:

* [ios, macos] Simplified expression document headings

* [ios, macos] Documented mgl_join:

* [ios, macos] Convert length operator to length: for strings

Only works for literal strings.

* [ios, macos] Implemented type conversion using CAST()

* [ios, macos] Aftermarket let expressions

* [ios, macos] Refactored aftermarket expression functions

Refactored the installation of aftermarket expression functions to use macros. It is no longer necessary to handwrite the type encoding of a function. Also added aftermarket functions for interpolating and stepping.

* [ios, macos] Updated documentation, tests, demo apps

* [ios, macos] Added generic expression function

* [ios, macos] Add MGL_MATCH function placeholder.

* [ios, macos] Add MGL_SWITCH expression operator.

* [ios, macos] Add mgl_coalesce: as expression function.

* [ios, macos] Update style documentation.

* [ios, macos] Add conventional custom function support.

* [ios, macos] Updated example code

* [ios, macos] Add mgl_coalesce conventional custom function support.

* [ios, macos] Add aftermarket function to 'has' operator.

* [ios, macos] Add documentation for lookup and feature operators.

* [ios, macos] Documented simple lookup

* [ios, macos] Renamed, reversed has expression

Renamed mgl_hasProperty:properties: to mgl_does:have: for better readability and consistency with the conventional mgl_has: function. Documented both forms of mgl_has:.

* [ios, macos] Restored OEM conditionals where available

This is the preferred syntax for simple conditionals on iOS 9 and above, because you can inline the predicate instead of wrapping it in a constant value expression, which means you can write a conditional in a single format string.

* [ios, macos] Update style docs.

Co-authored-by: Fabian Guerra <fabian.guerra@mapbox.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/platform/macos/docs/guides/Using Style Functions at Runtime.md b/platform/macos/docs/guides/Using Style Functions at Runtime.md
index 4e854aaaa0..e87cd00185 100644
--- a/platform/macos/docs/guides/Using Style Functions at Runtime.md
+++ b/platform/macos/docs/guides/Using Style Functions at Runtime.md
@@ -66,7 +66,7 @@ let stops: [Float: NSColor] = [
 ]
 
 let layer = MGLCircleStyleLayer(identifier: "circles", source: source)
-layer.circleColor = NSExpression(format: "FUNCTION(mag, 'mgl_interpolateWithCurveType:parameters:stops:', 'linear', nil, %@)",
+layer.circleColor = NSExpression(format: "mgl_interpolate:withCurveType:parameters:stops:(mag, 'linear', nil, %@)",
                                  stops)
 layer.circleRadius = NSExpression(forConstantValue: 10)
 mapView.style?.insertLayer(layer, below: symbolLayer)
@@ -92,7 +92,7 @@ let stops = [
     18: 18,
 ]
 
-layer.circleRadius = NSExpression(format: "FUNCTION($zoomLevel, 'mgl_interpolateWithCurveType:parameters:stops:', 'exponential', 1.5, %@)",
+layer.circleRadius = NSExpression(format: "mgl_interpolate:withCurveType:parameters:stops:($zoomLevel, 'exponential', 1.5, %@)",
                                   stops)
 ```
 
@@ -111,7 +111,7 @@ let stops: [Float: NSColor] = [
     10: .white,
 ]
 
-layer.circleColor = NSExpression(format: "FUNCTION(mag, 'mgl_stepWithMinimum:stops:', %@, %@)",
+layer.circleColor = NSExpression(format: "mgl_step:from:stops:(mag, %@, %@)",
                                  NSColor.green, stops)
 ```