identity function, repl upgrade

1 files changed, 46 insertions, 0 deletions

diff --git a/src/interpreter/builtins.ts b/src/interpreter/builtins.ts
index bc666e9..16322f1 100644
--- a/src/interpreter/builtins.ts
+++ b/src/interpreter/builtins.ts
@@ -202,6 +202,51 @@ const addBinaryArithmeticOperationsTo = (env: Environment) => {
   return env;
 };
 
+const addIdentityFunctionTo = (env: Environment) => {
+  env.set('id', {
+    type: 'function',
+    value: {
+      signatures: [
+        {
+          arguments: ['null'],
+          return: 'null',
+        },
+        {
+          arguments: ['int'],
+          return: 'int',
+        },
+        {
+          arguments: ['real'],
+          return: 'real',
+        },
+        {
+          arguments: ['bool'],
+          return: 'bool',
+        },
+        {
+          arguments: ['string'],
+          return: 'string',
+        },
+        {
+          arguments: ['bytearray'],
+          return: 'bytearray',
+        },
+        {
+          arguments: ['function'],
+          return: 'function',
+        },
+        {
+          arguments: ['reference'],
+          return: 'reference',
+        },
+      ],
+      body: ({ value }: Denotable) => value,
+    },
+  });
+
+  return env;
+};
+
 export const putBuiltinsOnEnvironemtn = (env: Environment) => {
   return [
     addBinaryArithmeticOperationsTo,
@@ -210,5 +255,6 @@ export const putBuiltinsOnEnvironemtn = (env: Environment) => {
     addNumberComparisonOperationsTo,
     addBooleanAlgebraOperationsTo,
     addEqualityOperationsTo,
+    addIdentityFunctionTo,
   ].reduce((acc, builtinsAdder) => builtinsAdder(acc), env);
 };