From 2e0dfdf3faf62f97f9440f164cb957a3d184a8bd Mon Sep 17 00:00:00 2001
From: ProgramSnail <PurpureBacterium@yandex.ru>
Date: Wed, 19 Jul 2023 10:25:24 +0300
Subject: [PATCH] operator definitions

---
 corpus/test.langexp | 13 +++++++++++++
 grammar.g4          |  2 +-
 grammar.js          |  4 +---
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/corpus/test.langexp b/corpus/test.langexp
index 02fe5dd..4090f83 100644
--- a/corpus/test.langexp
+++ b/corpus/test.langexp
@@ -106,6 +106,8 @@ func_2 = {
   print t.0;
 }
 
+( - ) 'a 'b = 'a + neg 'b;
+
 test.something = {
   do_something a b c;
 }
@@ -588,6 +590,17 @@ arg_deduction_example 'name 'duration : <- String <- Float -> Task = Task 'name
         (tuple_access
           (simple_name_identifier)
           (number_literal)))))
+  (function_definition
+    (operator)
+    (argument_name_identifier)
+    (argument_name_identifier)
+    (operator_expression
+      (name_expression
+        (argument_name_identifier))
+      (operator)
+      (name_expression
+        (simple_name_identifier)
+        (argument_name_identifier))))
   (function_definition
     (simple_name_identifier)
     (block
diff --git a/grammar.g4 b/grammar.g4
index 7e34246..588f6b0 100644
--- a/grammar.g4
+++ b/grammar.g4
@@ -23,7 +23,7 @@ type_definition: (DEFINITION_INFO)? (ANNOTATION_INFO)* ('^')?
                  ;
 
 function_definition: (definietion_info)? (ANNOTATION_INFO)* (constraint ';')*
-                     (('%' | 'let') | ('$' | 'var'))? SIMPLE_NAME_IDENTIFIER
+                     (('%' | 'let') | ('$' | 'var'))? (SIMPLE_NAME_IDENTIFIER | ('(' OPERATOR ')'))
                      ((ANNOTATION_IDENTIFIER)? ARGUMENT_NAME_IDENTIFIER ('?')?)*
                      (':' ((ANNOTATION_IDENTIFIER)? ('->' | 'in') | ('<-' | 'out') | ('<>' | 'ref'))? type)+)?
                      (('=' ( /*prec 2*/ block | (super_expression ';'))) | ';')
diff --git a/grammar.js b/grammar.js
index d753731..c81c5c1 100644
--- a/grammar.js
+++ b/grammar.js
@@ -53,7 +53,7 @@ module.exports = grammar({
       repeat($.annotation_info),
       repeat(seq($.constraint, ';')),
       /*optional(seq(*/optional(choice(choice('%', 'let'), choice('$', 'var')))/*, '.'))*/,
-      field('name', $.simple_name_identifier),
+      choice(field('name', $.simple_name_identifier), seq('(', field('name', $.operator), ')')),
       repeat(seq(
         optional($.annotation_identifier),
         $.argument_name_identifier,
@@ -248,9 +248,7 @@ module.exports = grammar({
     _type_identifier: $ => choice($.argument_type_identifier, $.simple_type_identifier),
 
     placeholder: $ => '_',
-
     simple_name_identifier: $ => token(seq(repeat(seq(/[a-z_][a-z0-9_]*/, '.')), /[a-z_][a-z0-9_]*/)),
-
     simple_type_identifier: $ => /([a-z_][a-z0-9_]*\.)*[A-Z][a-zA-Z0-9]*/,
     typeclass_identifier: $ => /([a-z_][a-z0-9_]*\.)*#[A-Z][a-zA-Z0-9]*/,
     argument_name_identifier: $ => /'[a-z_][a-z0-9_]*/,