Grammar notes update for Swift implementation

Author: yuryleb

Grammar.md

@@ -15,7 +15,7 @@ The quite universal and simplier solution is the changing street names with the
 The required grammatical case should be specified right in instruction's substitution variables:
 
 - `{way_name}` and `{rotary_name}` variables in translated instructions should be appended with required grammar case name after colon: `{way_name:accusative}` for example
-- [languages/grammar](languages/grammar/) folder should contain language-specific JSON file with regular expressions for specified grammar case:
+- [languages/grammar](languages/grammar/) folder should contain language-specific JSON file with regular expressions for specified grammatical case:
 ```json
 {
     "v5": {
@@ -28,9 +28,21 @@ The required grammatical case should be specified right in instruction's substit
 - Instruction text formatter ([index.js](index.js) in this module) should:
   - check `{way_name}` and `{rotary_name}` variables for optional grammar case after colon: `{way_name:accusative}`
   - find appropriate regular expressions block for target language and specified grammar case
-  - call standard [string replace with regular expression](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace) for each expression in block passing result from previous call to the next; the first call should enclose original street name with whitespaces to make parsing words in names a bit simplier.
+  - call standard [string replace with regular expression](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace) for each expression in block passing result from previous call to the next; the first call should enclose original street name with whitespaces to make parsing several words inside name a bit simplier.
 - Strings replacement with regular expression is available in almost all other programming language and so this should not be the problem for other code used OSRM Text Instructions' data only.
-- If there is no regular expression matched source name (that's for names from foreign country for example), original name is returned without changes. This is also expected behavior of standard [string replace with regular expression](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace). And the same behavior is expected in case of missing grammar JSON file or grammar case inside it.
+- Grammar JSON could have [regular expression flags in JS notation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp):
+```json
+{
+    "meta": {
+        "regExpFlags": "ig"
+    },
+```
+- Please note, not all JS regular expression flags could be supported in other languages.
+  For example, [OSRM Text Instructions for Swift](https://github.com/Project-OSRM/osrm-text-instructions.swift/) don't support "non-global match" and so always supposes `g` flag turned on.
+  So if some regular expressions suppose stopping after their match, please include `^` and/or `$` into patterns for exact matching or return "finished" string in replace expression without enclosing whitespaces.
+- If there is no regular expression matched source name (that's for names from foreign country for example), original name is returned without changes.
+  This is also expected behavior of standard [string replace with regular expression](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace).
+  And the same behavior is expected in case of missing grammar JSON file or grammar case inside it.
 
 ### Example
 
@@ -50,4 +62,5 @@ Russian _"Большая Монетная улица"_ street from St Petersburg
 
 - Russian regular expressions are based on [Garmin Russian TTS voices update](https://github.com/yuryleb/garmin-russian-tts-voices) project; see [file with regular expressions to apply to source text before pronouncing by TTS](https://github.com/yuryleb/garmin-russian-tts-voices/blob/master/src/Pycckuu__Milena%202.10/RULESET.TXT).
 - There is another grammar-supporting module - [jquery.i18n](https://github.com/wikimedia/jquery.i18n) - but unfortunately it has very poor implementation in part of grammatical case applying and is supposed to work with single words only.
-- Actually it would be great to get street names also in target language not from default OSM `name` only - there are several multi-lingual countries supporting several `name:<lang>` names for streets. But this the subject to address to [OSRM engine](https://github.com/Project-OSRM/osrm-backend) first.
+- Actually it would be great to get street names also in target language not from default OSM `name` only - there are several multi-lingual countries supporting several `name:<lang>` names for streets.
+  But this the subject to address to [OSRM engine](https://github.com/Project-OSRM/osrm-backend).

languages/grammar/ru.json

@@ -370,12 +370,9 @@
             ["^ (\\d+)-е (\\S+[ео])е [Шш]оссе ", " $1му $2му шоссе "],
             ["^ (\\d+)-е (\\S+ье) [Шш]оссе ", " $1му $2му шоссе "],
 
-            [" Третому ", " Третьему "],
-            [" третому ", " третьему "],
-            ["жому ", "жьему "],
-            ["жой ", "жей "],
-            ["чому ", "чьему "],
-            ["чой ", "чей "]
+            [" ([Тт])ретому ", " $1ретьему "],
+            ["([жч])ому ", "$1ьему "],
+            ["([жч])ой ", "$1ей "]
         ],
         "genitive": [
             ["^ (\\S+)ая [Аа]ллея ", " $1ой аллеи "],
@@ -663,10 +660,8 @@
             ["^ (\\d+)-е (\\S+[ео])е [Шш]оссе ", " $1го $2го шоссе "],
             ["^ (\\d+)-е (\\S+ье) [Шш]оссе ", " $1го $2го шоссе "],
 
-            [" Третого ", " Третьего "],
-            [" третого ", " третьего "],
-            ["жого ", "жьего "],
-            ["чого ", "чьего "]
+            [" ([Тт])ретого ", " $1ретьего "],
+            ["([жч])ого ", "$1ьего "]
         ],
         "prepositional": [
             ["^ (\\S+)ая [Аа]ллея ", " $1ой аллее "],
@@ -954,10 +949,8 @@
             ["^ (\\d+)-е (\\S+[ео])е [Шш]оссе ", " $1м $2м шоссе "],
             ["^ (\\d+)-е (\\S+ье) [Шш]оссе ", " $1м $2м шоссе "],
 
-            [" Третом ", " Третьем "],
-            [" третом ", " третьем "],
-            ["жом ", "жьем "],
-            ["чом ", "чьем "]
+            [" ([Тт])ретом ", " $1ретьем "],
+            ["([жч])ом ", "$1ьем "]
         ]
     }
 }