chore: add midas snippets

vscode-ext/package.json

@@ -4,7 +4,9 @@
     "engines": {
         "vscode": "*"
     },
-    "categories": ["Programming Languages"],
+    "categories": [
+        "Programming Languages"
+    ],
     "contributes": {
         "languages": [
             {
@@ -24,6 +26,12 @@
                 "scopeName": "source.midas",
                 "path": "./syntaxes/midas.tmLanguage.json"
             }
+        ],
+        "snippets": [
+            {
+                "language": "midas",
+                "path": "./snippets.json"
+            }
         ]
     }
 }

vscode-ext/snippets.json

@@ -0,0 +1,50 @@
+{
+    "Type alias": {
+        "prefix": "alias",
+        "body": "alias ${1:name} = $0",
+        "description": "Declare a type alias"
+    },
+    "Derived type": {
+        "prefix": "type",
+        "body": "type ${1:name} = $0",
+        "description": "Declare a derived type"
+    },
+    "Predicate": {
+        "prefix": "predicate",
+        "body": "predicate ${1:signature} = $0",
+        "description": "Declare a predicate"
+    },
+    "Extend": {
+        "prefix": "extend",
+        "body": [
+            "extend ${1:type} {",
+            "\t$0",
+            "}"
+        ],
+        "description": "Extend a type to add members"
+    },
+    "Property": {
+        "prefix": "prop",
+        "body": "prop ${1:name}: $0",
+        "description": "Declare a property"
+    },
+    "Method": {
+        "prefix": "def",
+        "body": "def ${1:name}: $0",
+        "description": "Declare a method"
+    },
+    "Function type": {
+        "prefix": "fn",
+        "body": "fn(${1:parameters}) -> ${2:returns}",
+        "description": "A function type"
+    },
+    "Frame type": {
+        "prefix": "frame",
+        "body": [
+            "Frame[",
+            "\t$0",
+            "]"
+        ],
+        "description": "A frame type"
+    }
+}