Add string interpolation

corpus/expressions.txt

@@ -187,3 +187,18 @@ multiple = { i | i in X, j in Y where i == j};
   (assignment (identifier) (set_comprehension (identifier) (generator (identifier) (identifier))))
   (assignment (identifier) (set_comprehension (identifier) (generator (identifier) (identifier) (infix_operator (identifier) (integer_literal)))))
   (assignment (identifier) (set_comprehension (identifier) (generator (identifier) (identifier)) (generator (identifier) (identifier) (infix_operator (identifier) (identifier))))))
+
+====================
+String Interpolation
+====================
+
+simple = "\(x)";
+with_text = "the \(i)th variable";
+multiple = "\(x) and \(y)";
+
+---
+
+(source_file
+  (assignment (identifier) (string_interpolation (identifier)))
+  (assignment (identifier) (string_interpolation (string_content) (identifier) (string_content)))
+  (assignment (identifier) (string_interpolation (identifier) (string_content) (identifier))))

grammar.js

@@ -55,6 +55,7 @@ module.exports = grammar({
       $.infix_operator,
       $.prefix_operator,
       $.set_comprehension,
+      $.string_interpolation,
       // TODO: Other expression types
       seq('(', $._expression, ')'),
     ),
@@ -136,6 +137,11 @@ module.exports = grammar({
       '{', $._expression, '|', sepBy1(',', $.generator), '}',
     ),
 
+    // TODO: Decide if string_literal and string_interpolation should be combined
+    string_interpolation: $ => seq(
+      '"', optional($.string_content), repeat1(seq('\\(', $._expression, ')', optional($.string_content))), '"',
+    ),
+
     _literal: $ => choice(
       $.absent,
       $.array_literal,
@@ -162,14 +168,11 @@ module.exports = grammar({
     )),
     set_literal: $ => seq('{', sepBy(',', $._expression), '}'),
 
-    string_literal: $ => seq(
+    string_literal: $ => seq('"', alias(optional($.string_content), 'content'), '"'),
-      '"',
+    string_content: $ => repeat1(choice(
-      repeat(choice(
       token.immediate(prec(1, /[^"\n\\]+/)),
       $.escape_sequence
     )),
-      '"'
-    ),
     escape_sequence: $ => token.immediate(seq(
       '\\',
       choice(

src/grammar.json

@@ -117,6 +117,10 @@
           "type": "SYMBOL",
           "name": "set_comprehension"
         },
+        {
+          "type": "SYMBOL",
+          "name": "string_interpolation"
+        },
         {
           "type": "SEQ",
           "members": [
@@ -1172,6 +1176,63 @@
         }
       ]
     },
+    "string_interpolation": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "\""
+        },
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "SYMBOL",
+              "name": "string_content"
+            },
+            {
+              "type": "BLANK"
+            }
+          ]
+        },
+        {
+          "type": "REPEAT1",
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "\\("
+              },
+              {
+                "type": "SYMBOL",
+                "name": "_expression"
+              },
+              {
+                "type": "STRING",
+                "value": ")"
+              },
+              {
+                "type": "CHOICE",
+                "members": [
+                  {
+                    "type": "SYMBOL",
+                    "name": "string_content"
+                  },
+                  {
+                    "type": "BLANK"
+                  }
+                ]
+              }
+            ]
+          }
+        },
+        {
+          "type": "STRING",
+          "value": "\""
+        }
+      ]
+    },
     "_literal": {
       "type": "CHOICE",
       "members": [
@@ -1362,7 +1423,30 @@
           "value": "\""
         },
         {
-          "type": "REPEAT",
+          "type": "ALIAS",
+          "content": {
+            "type": "CHOICE",
+            "members": [
+              {
+                "type": "SYMBOL",
+                "name": "string_content"
+              },
+              {
+                "type": "BLANK"
+              }
+            ]
+          },
+          "named": false,
+          "value": "content"
+        },
+        {
+          "type": "STRING",
+          "value": "\""
+        }
+      ]
+    },
+    "string_content": {
+      "type": "REPEAT1",
       "content": {
         "type": "CHOICE",
         "members": [
@@ -1384,12 +1468,6 @@
         ]
       }
     },
-        {
-          "type": "STRING",
-          "value": "\""
-        }
-      ]
-    },
     "escape_sequence": {
       "type": "IMMEDIATE_TOKEN",
       "content": {

src/node-types.json

@@ -71,6 +71,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -146,6 +150,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -229,6 +237,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -332,6 +344,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -350,6 +366,21 @@
       }
     }
   },
+  {
+    "type": "content",
+    "named": false,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": false,
+      "types": [
+        {
+          "type": "escape_sequence",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "generator",
     "named": true,
@@ -418,6 +449,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -525,6 +560,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -601,6 +640,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -684,6 +727,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -766,6 +813,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -850,6 +901,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -1054,6 +1109,10 @@
             "type": "set_literal",
             "named": true
           },
+          {
+            "type": "string_interpolation",
+            "named": true
+          },
           {
             "type": "string_literal",
             "named": true
@@ -1149,6 +1208,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -1228,6 +1291,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -1303,6 +1370,10 @@
           "type": "set_literal",
           "named": true
         },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
         {
           "type": "string_literal",
           "named": true
@@ -1326,7 +1397,7 @@
     }
   },
   {
-    "type": "string_literal",
+    "type": "string_content",
     "named": true,
     "fields": {},
     "children": {
@@ -1340,6 +1411,94 @@
       ]
     }
   },
+  {
+    "type": "string_interpolation",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": true,
+      "required": true,
+      "types": [
+        {
+          "type": "absent",
+          "named": true
+        },
+        {
+          "type": "array_comprehension",
+          "named": true
+        },
+        {
+          "type": "array_literal",
+          "named": true
+        },
+        {
+          "type": "boolean_literal",
+          "named": true
+        },
+        {
+          "type": "call",
+          "named": true
+        },
+        {
+          "type": "float_literal",
+          "named": true
+        },
+        {
+          "type": "generator_call",
+          "named": true
+        },
+        {
+          "type": "identifier",
+          "named": true
+        },
+        {
+          "type": "if_then_else",
+          "named": true
+        },
+        {
+          "type": "indexed_access",
+          "named": true
+        },
+        {
+          "type": "infix_operator",
+          "named": true
+        },
+        {
+          "type": "integer_literal",
+          "named": true
+        },
+        {
+          "type": "prefix_operator",
+          "named": true
+        },
+        {
+          "type": "set_comprehension",
+          "named": true
+        },
+        {
+          "type": "set_literal",
+          "named": true
+        },
+        {
+          "type": "string_content",
+          "named": true
+        },
+        {
+          "type": "string_interpolation",
+          "named": true
+        },
+        {
+          "type": "string_literal",
+          "named": true
+        }
+      ]
+    }
+  },
+  {
+    "type": "string_literal",
+    "named": true,
+    "fields": {}
+  },
   {
     "type": "!=",
     "named": false
@@ -1436,6 +1595,10 @@
     "type": "[",
     "named": false
   },
+  {
+    "type": "\\(",
+    "named": false
+  },
   {
     "type": "\\/",
     "named": false