Update documentation

docs/lang/syntax.md

@@ -57,6 +57,12 @@ For every variable `x` larger than a byte, extra subvariables are defined:
     * constituent bytes, from low to high: `x.b0`, `x.b1`, `x.b2`, `x.b3`
     
     * partial words: `x.loword` (=`x.b1:x.b0`), `x.hiword` (=`x.b3:x.b2`)
+    
+* if `x` is of a larger integral type:
+
+    * constituent bytes, from low to high: `x.b0`, `x.b1`, `x.b2`, etc.
+    
+    * the lowest word: `x.loword` (=`x.b1:x.b0`)
 
 ### Constant declarations
 
@@ -100,12 +106,16 @@ An array is a continuous sequence of bytes in memory.
 
 Syntax:
 
-`[segment(<segment>)] array <name> [[<size>]] [align ( <alignment> )] [@<address>] [= <initial_values>]`
+`[segment(<segment>)] array [(<element type>)] <name> [[<size>]] [align ( <alignment> )] [@<address>] [= <initial_values>]`
 
 * `<segment>`: segment name; if absent,
 then defaults to `default_code_segment` as defined for the platform if the array has initial values,
 or to `default` if it doesn't.
 
+* `<element type>`: type of the elements of the array.
+It must be of size 1 byte.
+If omitted, the default is `byte`.
+
 * `<size>`: either a constant number, which then defines the size of the array,
 or a name of a plain enumeration type, in which case changes the type of the index to that enumeration
 and declares the array size to be equal to the number of variants in that enumeration.