feat: implement support for EnvOp in heap

src/go-slang/ece.ts

@@ -111,9 +111,6 @@ export function evaluate(program: SourceFile, slangContext: SlangContext): Value
     }
   }
 
-  // TEMP: for debugging purposes
-  console.log('Total memory allocated: ', H._debug_num_allocations() * 8, 'bytes')
-
   return 'Program exited'
 }
 
@@ -128,8 +125,8 @@ const interpreter: {
     E.declare(id.name, { type: CommandType.ClosureOp, funcDeclNodeUid, envId: E.id() } as ClosureOp)
   },
 
-  Block: ({ statements }: Block, { C, E }) => {
-    C.pushR(...statements, { type: CommandType.EnvOp, envId: E.id() })
+  Block: ({ statements }: Block, { C, E, H }) => {
+    C.pushR(...statements, H.alloc({ type: CommandType.EnvOp, envId: E.id() }))
     E.extend({})
   },
 
@@ -240,7 +237,7 @@ const interpreter: {
       return new FuncArityError(calleeId.name, values.length, params.length)
     }
 
-    C.pushR(body, RetMarker, { type: CommandType.EnvOp, envId: E.id() })
+    C.pushR(body, RetMarker, H.alloc({ type: CommandType.EnvOp, envId: E.id() }))
     // set the environment to the closure's environment
     E.setId(envId).extend(Object.fromEntries(zip(paramNames, values)))
   },

src/go-slang/lib/heap/index.ts

@@ -1,4 +1,13 @@
-import { BuiltinOp, CallOp, ClosureOp, CommandType, Node, isCommand, isNode } from '../../types'
+import {
+  BuiltinOp,
+  CallOp,
+  ClosureOp,
+  CommandType,
+  EnvOp,
+  Node,
+  isCommand,
+  isNode
+} from '../../types'
 import { AstMap } from '../astMap'
 import { DEFAULT_HEAP_SIZE, WORD_SIZE } from './config'
 import { PointerTag } from './tags'
@@ -56,6 +65,8 @@ export class Heap {
           return this.allocateBuiltinOp(value)
         case CommandType.ClosureOp:
           return this.allocateClosureOp(value)
+        case CommandType.EnvOp:
+          return this.allocateEnvOp(value)
       }
     }
 
@@ -106,6 +117,11 @@ export class Heap {
           funcDeclNodeUid: this.memory.getInt16(mem_addr + 1),
           envId: this.memory.getInt16(mem_addr + 3)
         } as ClosureOp
+      case PointerTag.EnvOp:
+        return {
+          type: CommandType.EnvOp,
+          envId: this.memory.getInt16(mem_addr + 1)
+        } as EnvOp
     }
   }
 
@@ -177,6 +193,17 @@ export class Heap {
     return ptr_heap_addr
   }
 
+  /* Memory Layout of an EnvOp: [0:tag, 1-2:envId, 3-4:_unused_, 5-6:size, 7:_unused_] (1 word) */
+  private allocateEnvOp({ envId }: EnvOp): HeapAddress {
+    const ptr_heap_addr = this.allocateTaggedPtr(PointerTag.EnvOp)
+
+    const ptr_mem_addr = ptr_heap_addr * WORD_SIZE
+    // NOTE: assume there will be no more than 2^16 envs
+    this.memory.setInt16(ptr_mem_addr + 1, envId)
+
+    return ptr_heap_addr
+  }
+
   /**
    * Allocate a tagged pointer in the heap
    *

src/go-slang/lib/heap/tags.ts

@@ -5,5 +5,6 @@ export enum PointerTag {
   AstNode,
   CallOp,
   BuiltInOp,
-  ClosureOp
+  ClosureOp,
+  EnvOp
 }