Compare arrays/maps by structure

Closes #71

Author: MatheusRich

CHANGELOG.md

@@ -1,5 +1,17 @@
 ## Unreleased - [Full diff](https://github.com/lit-lang/lit/compare/v0.2.0...main)
 
+- Compare arrays/maps by structure
+
+```lit
+let a = [1, 2, 3]
+let b = [1, 2, 3]
+println a == b # true
+
+let m = {a: 1, b: 2}
+let n = {b: 2, a: 1}
+println m == n # true
+```
+
 - Add symbol-string shorthand syntax for maps
 
 ```lit

spec/e2e/operator/equals.lit

@@ -12,3 +12,21 @@ println("str" == "ing") # expect: false
 println(nil == false) # expect: false
 println(false == 0) # expect: false
 println(0 == "0") # expect: false
+
+# compound types
+println([] == []) # expect: true
+println([1, "foo"] == [1, "foo"]) # expect: true
+println([1, "foo"] == ["foo", 1]) # expect: false
+
+println({:} == {:}) # expect: true
+println({1 : "a"} == {1 : "a"}) # expect: true
+println({1 : "a", 2 : "b"} == {2 : "b", 1 : "a"}) # expect: true
+println({1 : "a"} == {2 : "b"}) # expect: false
+
+# custom types
+type Foo {}
+println(Foo() == Foo()) # expect: false
+type Bar {
+  init do |x| self.x = x
+}
+println(Bar(1) == Bar(1)) # expect: false

src/lit/stdlib/lit_array.cr

@@ -112,5 +112,9 @@ module Lit
     def set(name : Token, value : Value)
       raise RuntimeError.new(name, "Cannot set properties on array.")
     end
+
+    def ==(other : LitArray) : Bool
+      return @elements == other.elements
+    end
   end
 end

src/lit/stdlib/lit_map.cr

@@ -57,5 +57,9 @@ module Lit
     def set(name : Token, value : Value)
       raise RuntimeError.new(name, "Cannot set properties on array.")
     end
+
+    def ==(other : LitMap) : Bool
+      return @elements == other.elements
+    end
   end
 end