From e8bcd324458335d280a45181b58e50a2eb077da9 Mon Sep 17 00:00:00 2001
From: Chris Pressey <cpressey@catseye.tc>
Date: Wed, 23 Feb 2022 21:30:00 +0000
Subject: [PATCH] Remove the deep struct equality implementation from backends.

---
 TODO.md                            |  2 --
 src/castile/backends/c.py          | 25 +------------------------
 src/castile/backends/javascript.py | 22 ++--------------------
 3 files changed, 3 insertions(+), 46 deletions(-)

diff --git a/TODO.md b/TODO.md
index 15c7a96..145365c 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,8 +3,6 @@ TODO
 
 ### Implementation ###
 
-Remove the deep struct equality implementation from backends.
-
 Name mangling for compilers (prepend with `_` most likely.)
 
 And literal characters in strings, especially `'` and `"`.
diff --git a/src/castile/backends/c.py b/src/castile/backends/c.py
index 16fbac4..ecd200a 100644
--- a/src/castile/backends/c.py
+++ b/src/castile/backends/c.py
@@ -199,25 +199,6 @@ def compile(self, ast):
             self.indent -= 1
             self.write_indent('}\n\n')
 
-            # FIXME the language no longer supports this, it can be jettisoned
-            self.write_indent('int equal_%s(struct %s * a, struct %s * b) {\n' % (ast.value, ast.value, ast.value))
-
-            self.indent += 1
-            for child in field_defns:
-                assert child.tag == 'FieldDefn', child.tag
-                child_type = child.children[0]
-                if child_type.tag == 'StructType':
-                    struct_type = child_type.value
-                    self.write_indent('if (!equal_%s(a->%s, b->%s)) return 0;\n' % (struct_type, child.value, child.value))
-                elif child_type.tag == 'UnionType':
-                    self.write_indent('if (!equal_tagged_value(a->%s, b->%s)) return 0;\n' % (child.value, child.value))
-                else:
-                    self.write_indent('if (a->%s != b->%s) return 0;\n' % (child.value, child.value))
-
-            self.write_indent('return 1;\n')
-            self.indent -= 1
-            self.write_indent('}\n\n')
-
         elif ast.tag == 'FieldDefn':
             self.write_indent('%s;\n' % self.c_decl(ast.children[0].type, ast.value))
         elif ast.tag == 'FunLit':
@@ -257,11 +238,7 @@ def compile(self, ast):
             self.indent -= 1
         elif ast.tag == 'Op':
             if ast.value == '==' and isinstance(ast.children[0].type, Struct):
-                self.write('equal_%s(' % ast.children[0].type.name)
-                self.compile(ast.children[0])
-                self.write(', ')
-                self.compile(ast.children[1])
-                self.write(')')
+                raise NotImplementedError('structs cannot be compared for equality')
             elif ast.value == '==' and isinstance(ast.children[0].type, Union):
                 self.write('equal_tagged_value(')
                 self.compile(ast.children[0])
diff --git a/src/castile/backends/javascript.py b/src/castile/backends/javascript.py
index 555dca4..e6dbe17 100644
--- a/src/castile/backends/javascript.py
+++ b/src/castile/backends/javascript.py
@@ -72,21 +72,7 @@ def compile(self, ast):
         elif ast.tag == 'Forward':
             pass
         elif ast.tag == 'StructDefn':
-            # FIXME the language no longer supports this, it can be jettisoned
-            field_defns = ast.children[0].children
-            self.write('function equal_%s(a, b) {\n' % ast.value)
-            for child in field_defns:
-                assert child.tag == 'FieldDefn', child.tag
-                child_type = child.children[0]
-                if child_type.tag == 'StructType':
-                    struct_type = child_type.value
-                    self.write_indent('if (!equal_%s(a.%s, b.%s)) return false;\n' % (struct_type, child.value, child.value))
-                elif child_type.tag == 'UnionType':
-                    self.write_indent('if (!equal_tagged_value(a.%s, b.%s)) return 0;\n' % (child.value, child.value))
-                else:
-                    self.write_indent('if (a.%s !== b.%s) return false;\n' % (child.value, child.value))
-            self.write('return true;\n')
-            self.write('}\n\n')
+            pass
         elif ast.tag == 'FunLit':
             self.write('function(')
             self.compile(ast.children[0])
@@ -123,11 +109,7 @@ def compile(self, ast):
             self.compile(ast.children[1])
         elif ast.tag == 'Op':
             if ast.value == '==' and isinstance(ast.children[0].type, Struct):
-                self.write('equal_%s(' % ast.children[0].type.name)
-                self.compile(ast.children[0])
-                self.write(', ')
-                self.compile(ast.children[1])
-                self.write(')')
+                raise NotImplementedError('structs cannot be compared for equality')
             elif ast.value == '==' and isinstance(ast.children[0].type, Union):
                 self.write('equal_tagged_value(')
                 self.compile(ast.children[0])