Add binary expression

grammar.js

@@ -71,6 +71,8 @@ module.exports = grammar({
       // Composites
       $.list_expression,
       $.map_expression,
+      // Operators
+      $.binary_expression,
     ),
 
     // The Blueprint scanner makes use of Go's lexer, so copy their rule
@@ -185,6 +187,12 @@ module.exports = grammar({
       "}",
     ),
 
+    binary_expression: ($) => prec.left(seq(
+      field("left", $._expr),
+      field("operator", "+"),
+      field("right", $._expr),
+    )),
+
     // }}}
 
     // Properties {{{

src/grammar.json

@@ -279,6 +279,10 @@
         {
           "type": "SYMBOL",
           "name": "map_expression"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "binary_expression"
         }
       ]
     },
@@ -830,6 +834,39 @@
         }
       ]
     },
+    "binary_expression": {
+      "type": "PREC_LEFT",
+      "value": 0,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "FIELD",
+            "name": "left",
+            "content": {
+              "type": "SYMBOL",
+              "name": "_expr"
+            }
+          },
+          {
+            "type": "FIELD",
+            "name": "operator",
+            "content": {
+              "type": "STRING",
+              "value": "+"
+            }
+          },
+          {
+            "type": "FIELD",
+            "name": "right",
+            "content": {
+              "type": "SYMBOL",
+              "name": "_expr"
+            }
+          }
+        ]
+      }
+    },
     "_colon_property": {
       "type": "SEQ",
       "members": [

src/node-types.json

@@ -31,6 +31,110 @@
         "multiple": false,
         "required": true,
         "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
+          {
+            "type": "boolean_literal",
+            "named": true
+          },
+          {
+            "type": "identifier",
+            "named": true
+          },
+          {
+            "type": "integer_literal",
+            "named": true
+          },
+          {
+            "type": "interpreted_string_literal",
+            "named": true
+          },
+          {
+            "type": "list_expression",
+            "named": true
+          },
+          {
+            "type": "map_expression",
+            "named": true
+          },
+          {
+            "type": "raw_string_literal",
+            "named": true
+          },
+          {
+            "type": "select_expression",
+            "named": true
+          }
+        ]
+      }
+    }
+  },
+  {
+    "type": "binary_expression",
+    "named": true,
+    "fields": {
+      "left": {
+        "multiple": false,
+        "required": true,
+        "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
+          {
+            "type": "boolean_literal",
+            "named": true
+          },
+          {
+            "type": "identifier",
+            "named": true
+          },
+          {
+            "type": "integer_literal",
+            "named": true
+          },
+          {
+            "type": "interpreted_string_literal",
+            "named": true
+          },
+          {
+            "type": "list_expression",
+            "named": true
+          },
+          {
+            "type": "map_expression",
+            "named": true
+          },
+          {
+            "type": "raw_string_literal",
+            "named": true
+          },
+          {
+            "type": "select_expression",
+            "named": true
+          }
+        ]
+      },
+      "operator": {
+        "multiple": false,
+        "required": true,
+        "types": [
+          {
+            "type": "+",
+            "named": false
+          }
+        ]
+      },
+      "right": {
+        "multiple": false,
+        "required": true,
+        "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
           {
             "type": "boolean_literal",
             "named": true
@@ -95,6 +199,10 @@
         "multiple": false,
         "required": true,
         "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
           {
             "type": "boolean_literal",
             "named": true
@@ -163,6 +271,10 @@
         "multiple": true,
         "required": false,
         "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
           {
             "type": "boolean_literal",
             "named": true
@@ -269,6 +381,10 @@
         "multiple": false,
         "required": true,
         "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
           {
             "type": "boolean_literal",
             "named": true
@@ -327,6 +443,10 @@
         "multiple": false,
         "required": true,
         "types": [
+          {
+            "type": "binary_expression",
+            "named": true
+          },
           {
             "type": "boolean_literal",
             "named": true
@@ -528,6 +648,10 @@
     "type": ")",
     "named": false
   },
+  {
+    "type": "+",
+    "named": false
+  },
   {
     "type": "+=",
     "named": false

test/corpus/expressions.txt

@@ -344,3 +344,27 @@ foo = {
     (identifier)
     (map_expression
       (ERROR))))
+
+================================================================================
+Binary operators
+================================================================================
+
+foo = [
+    -12 + -27 + 42,
+    "a" + "b",
+]
+
+--------------------------------------------------------------------------------
+
+(source_file
+  (assignment
+    (identifier)
+    (list_expression
+      (binary_expression
+        (binary_expression
+          (integer_literal)
+          (integer_literal))
+        (integer_literal))
+      (binary_expression
+        (interpreted_string_literal)
+        (interpreted_string_literal)))))