add support for Meson (XAMPPRocky#169)

* add support for Meson

Fixes: XAMPPRocky#168
Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

* tests: add meson.build

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

* remove unused variable

warning: unused variable: `key`
  --> build.rs:31:10
   |
31 |     for (key, ref mut item) in json.get_mut("languages")
   |          ^^^
   |
   = note: #[warn(unused_variables)] on by default
   = note: to avoid this warning, consider using `_key` instead

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

README.md

@@ -334,6 +334,7 @@ Lucius
 Madlang
 Makefile
 Markdown
+Meson
 ModuleDef
 Mustache
 Nim

build.rs

@@ -28,7 +28,7 @@ fn generate_languages(out_dir: &OsStr) {
         serde_json::from_reader(json).expect("Can't parse json")
     };
 
-    for (key, ref mut item) in json.get_mut("languages")
+    for (_key, ref mut item) in json.get_mut("languages")
                                    .unwrap()
                                    .as_object_mut()
                                    .unwrap()

languages.json

@@ -816,6 +816,19 @@
             "extensions": ["def"],
             "line_comment": [";"]
         },
+        "Meson":{
+            "line_comment":[
+                "#"
+            ],
+            "quotes":[
+                ["'", "'"],
+                ["'''", "'''"]
+            ],
+            "filenames":[
+                "meson.build",
+                "meson_options.txt"
+            ]
+        },
         "Mustache":{
             "multi_line":[
               ["{{!", "}}"]

tests/data/meson.build

@@ -0,0 +1,12 @@
+# 12 lines 6 code 2 comments 4 blanks
+
+project('xyz', 'c',
+        meson_version : '>=0.30.0') # not counted
+
+xyz_gen = '''
+# comment inside
+print("This is generated source.")
+'''
+
+# this is a comment
+