Different immutabilities (#172)

* separate constant values from immutable values * add a test
mlogjs · Apr 30, 2023 · d8c4266 · d8c4266
1 parent cd75edd
commit d8c4266
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Showing 6 changed files with 36 additions and 7 deletions.
diff --git a/compiler/src/handlers/VariableDeclaration.ts b/compiler/src/handlers/VariableDeclaration.ts
@@ -98,7 +98,11 @@ const DeclareIdentifier: TDeclareHandler<es.Identifier> = (
     handler(init, inst) {
       if (kind === "const" && !init)
         throw new CompilerError("Constants must be initialized.", node);
-      if (kind === "const" && init?.mutability === EMutability.constant) {
+      if (
+        kind === "const" &&
+        (init?.mutability === EMutability.constant ||
+          init?.mutability === EMutability.immutable)
+      ) {
         scope.set(identifier, init);
         return [null, inst];
       } else {
@@ -112,7 +116,7 @@ const DeclareIdentifier: TDeclareHandler<es.Identifier> = (
             );
           pipeInsts(value["="](scope, init), inst);
         }
-        if (kind === "const") value.mutability = EMutability.constant;
+        if (kind === "const") value.mutability = EMutability.immutable;
         return [null, inst];
       }
     },

diff --git a/compiler/src/macros/Memory.ts b/compiler/src/macros/Memory.ts
@@ -106,14 +106,17 @@ export class MemoryBuilder extends MacroFunction {
           "The memory size must be a number literal or a store."
         );
 
-      if (size.mutability === EMutability.constant) {
+      if (
+        size.mutability === EMutability.constant ||
+        size.mutability === EMutability.immutable
+      ) {
         return [new MemoryMacro(cell, size), []];
       }
 
       const name = extractOutName(out) ?? scope.makeTempName();
       const store = new StoreValue(`${name}.&len`);
       const [, inst] = store["="](scope, size);
-      store.mutability = EMutability.constant;
+      store.mutability = EMutability.immutable;
       return [new MemoryMacro(cell, store), inst];
     });
   }

diff --git a/compiler/src/macros/commands/Fetch.ts b/compiler/src/macros/commands/Fetch.ts
@@ -1,5 +1,5 @@
 import { InstructionBase } from "../../instructions";
-import { EMutability, IValue } from "../../types";
+import { IValue } from "../../types";
 import { ObjectValue, StoreValue } from "../../values";
 import { createOverloadNamespace } from "../util";
 
@@ -17,7 +17,7 @@ export class Fetch extends ObjectValue {
         buildCount: { args: ["team", "block"] },
       },
       handler(scope, overload, out, team, ...rest) {
-        const output = StoreValue.from(scope, out, EMutability.constant);
+        const output = StoreValue.from(scope, out);
 
         const params: (IValue | string)[] = ["0", "@conveyor"];
 

diff --git a/compiler/src/types.ts b/compiler/src/types.ts
@@ -252,10 +252,14 @@ export enum EMutability {
    * but it's still not safe from mutations coming from the runtime.
    */
   readonly,
-  /** Constant values, won't change during execution */
+  /** Compile-time constants.*/
   constant,
   /** An immutable value that hasn't been initialized yet */
   init,
+  /** A value unknown at compile-time
+   * that will not change after initialization
+   */
+  immutable,
 }
 
 export interface IValue extends IValueOperators {

diff --git a/compiler/test/in/switch_immutability.js b/compiler/test/in/switch_immutability.js
@@ -0,0 +1,11 @@
+const a = Math.rand(10);
+
+const b = 2;
+
+switch (b) {
+  case a:
+    print("is a");
+    break;
+  case 2:
+    print("is b");
+}
diff --git a/compiler/test/out/switch_immutability.mlog b/compiler/test/out/switch_immutability.mlog
@@ -0,0 +1,7 @@
+op rand a:1:6 10
+jump 3 strictEqual 2 a:1:6
+jump 5 always
+print "is a"
+jump 6 always
+print "is b"
+end