Merge pull request #140 from sugarlabs/refactor-syntax-add-scope

Refactor syntax add scope

Author: meganindya

src/@types/elements.d.ts

@@ -1,5 +1,6 @@
 import { TData, TDataName } from './data';
 import { TElementKind, TElementType } from './specification';
+import { IContext, ISymbolTable } from './scope';
 
 // -------------------------------------------------------------------------------------------------
 
@@ -42,37 +43,64 @@ export interface IElementArgument<T> extends IElementSyntax {
 export interface IElementData<T> extends IElementArgument<T> {
     /**
      * Evalutates the logic of the data element (usually based on the label).
+     * @param scope An object containing context and symbol table instances
      */
-    evaluate(): void;
+    evaluate(scope: { context: IContext; symbolTable: ISymbolTable }): void;
 }
 
 /** Generic interface for the class that implements an expression element. */
 export interface IElementExpression<T> extends IElementArgument<T> {
     /**
      * Evalutates the logic of the expression using the supplied parameters and stores the value.
-     * @param params - An object containing key-value pairs of each argument and it's value
+     * @param scope object containing context and symbol table instances
+     * @param params object containing key-value pairs of each argument and it's value
      */
-    evaluate(params: { [key: string]: TData }): void;
+    evaluate(
+        scope: { context: IContext; symbolTable: ISymbolTable },
+        params: { [key: string]: TData }
+    ): void;
 }
 
 /** Interface for the class that implements an instruction element. */
 export interface IElementInstruction extends IElementSyntax {
     /**
      * Executes the instruction using the supplied parameters.
-     * @param params - An object containing key-value pairs of each argument and it's value
+     * @param scope object containing context and symbol table instances
+     * @param params object containing key-value pairs of each argument and it's value
      */
-    onVisit(params: { [key: string]: TData }): void;
+    onVisit(
+        scope: { context: IContext; symbolTable: ISymbolTable },
+        params: { [key: string]: TData }
+    ): void;
 }
 
 /** Interface for the class that implements a statement element. */
 export interface IElementStatement extends IElementInstruction {}
 
 /** Interface for the class that implements a block element. */
 export interface IElementBlock extends IElementInstruction {
-    /** Executes before each containing instruction is executed. */
-    onInnerVisit(): void;
-    /** Executes after each containing instruction is executed. */
-    onInnerExit(): void;
-    /** Executes after all containing instructions are executed. */
-    onExit(): void;
+    /**
+     * Executes before each containing instruction is executed.
+     * @param scope object containing context and symbol table instances
+     */
+    onInnerVisit(
+        scope: { context: IContext; symbolTable: ISymbolTable },
+        params: { [key: string]: TData }
+    ): void;
+    /**
+     * Executes after each containing instruction is executed.
+     * @param scope object containing context and symbol table instances
+     */
+    onInnerExit(
+        scope: { context: IContext; symbolTable: ISymbolTable },
+        params: { [key: string]: TData }
+    ): void;
+    /**
+     * Executes after all containing instructions are executed.
+     * @param scope object containing context and symbol table instances
+     */
+    onExit(
+        scope: { context: IContext; symbolTable: ISymbolTable },
+        params: { [key: string]: TData }
+    ): void;
 }

src/@types/specification.d.ts

@@ -35,8 +35,9 @@ export interface IElementSpecificationData {
 }
 
 /** Type for the specification entry object for data elements. */
-export interface IElementSpecificationEntryData extends IElementSpecificationData {
-    classification: TElementClassification;
+export interface IElementSpecificationEntryData
+    extends Omit<IElementSpecificationData, 'classification'> {
+    category: string;
     label: string;
     type: 'Data';
     prototype: typeof IElementData;
@@ -51,8 +52,9 @@ export interface IElementSpecificationExpression {
 }
 
 /** Type for the specification object for expression elements. */
-export interface IElementSpecificationEntryExpression extends IElementSpecificationExpression {
-    classification: TElementClassification;
+export interface IElementSpecificationEntryExpression
+    extends Omit<IElementSpecificationEntryExpression, 'classification'> {
+    category: string;
     label: string;
     type: 'Expression';
     prototype: typeof IElementExpression;
@@ -78,8 +80,11 @@ export type IElementSpecificationStatement = IElementSpecificationInstruction &
 };
 
 /** Type for the specification object for statement elements. */
-export type IElementSpecificationEntryStatement = IElementSpecificationInstruction & {
-    classification: TElementClassification;
+export type IElementSpecificationEntryStatement = Omit<
+    IElementSpecificationStatement,
+    'classification'
+> & {
+    category: string;
     label: string;
     type: 'Statement';
     prototype: typeof IElementStatement;
@@ -96,8 +101,8 @@ export type IElementSpecificationBlock = IElementSpecificationInstruction & {
 };
 
 /** Type for the specification entry object for block elements. */
-export type IElementSpecificationEntryBlock = IElementSpecificationInstruction & {
-    classification: TElementClassification;
+export type IElementSpecificationEntryBlock = Omit<IElementSpecificationBlock, 'classification'> & {
+    category: string;
     label: string;
     type: 'Block';
     prototype: typeof IElementBlock;
@@ -131,3 +136,20 @@ export interface IElementSpecification {
 export interface IElementSpecificationSnapshot extends Omit<IElementSpecification, 'prototype'> {
     prototypeName: string;
 }
+
+/** Type definition for a table of element specification entries. */
+export type IElementSpecificationEntries = {
+    /** Element group name. */
+    [group: string]: {
+        /** Element specification entries by element name/identifier. */
+        entries: {
+            [identifier: string]:
+                | IElementSpecificationEntryData
+                | IElementSpecificationEntryExpression
+                | IElementSpecificationEntryStatement
+                | IElementSpecificationEntryBlock;
+        };
+        /** Element group context key-value dictionary. */
+        context?: Record<string, unknown>;
+    };
+};

src/execution/interpreter/index.spec.ts

@@ -1,13 +1,15 @@
 import { run } from '.';
 
 import { generateFromSnapshot, generateSnapshot } from '../../syntax/tree';
+import { ScopeStack } from '../../execution/scope';
 
 import { registerElementSpecificationEntries } from '../../syntax/specification';
 import elementSpecification from '../../library';
 
 // -------------------------------------------------------------------------------------------------
 
 registerElementSpecificationEntries(elementSpecification);
+const scopeStack = new ScopeStack();
 
 describe('Interpreter', () => {
     test('run a process and verify', () => {
@@ -147,6 +149,9 @@ describe('Interpreter', () => {
         const snapshot = generateSnapshot();
 
         const node = snapshot.process[0];
-        run(node.nodeID);
+        run(node.nodeID, {
+            context: scopeStack.getContext('programming'),
+            symbolTable: scopeStack.getSymbolTable(),
+        });
     });
 });

src/execution/interpreter/index.ts

@@ -1,6 +1,3 @@
-import type { TData, TDataName } from '../../@types/data';
-import type { IVariable, TPCOverride } from '../../@types/execution';
-
 import { addGlobalSymbol, getGlobalSymbol } from '../scope';
 import { setPCOverride, clearPCOverride, setExecutionItem, getNextElement } from '../parser';
 
@@ -11,7 +8,11 @@ import {
 } from '../../syntax/elements/elementArgument';
 import { ElementStatement, ElementBlock } from '../../syntax/elements/elementInstruction';
 
-// -- private functions ----------------------------------------------------------------------------
+// -- types ----------------------------------------------------------------------------------------
+
+import type { TData, TDataName } from '../../@types/data';
+import type { IVariable, TPCOverride } from '../../@types/execution';
+import type { IContext, ISymbolTable } from '../../@types/scope';
 
 // -- public functions -----------------------------------------------------------------------------
 
@@ -63,13 +64,28 @@ export function releaseProgramCounter(): void {
  * Runs a process, routine, or crumb stack from start to end.
  * @param nodeID syntax tree node ID of the starting node
  */
-export function run(nodeID: string): void {
+export function run(
+    nodeID: string,
+    scope: {
+        context: IContext<Record<string, unknown>>;
+        symbolTable: ISymbolTable;
+    }
+): void {
     abstract class ElementDataCover extends ElementData<TData> {
-        abstract evaluate(): void;
+        abstract evaluate(scope: {
+            context: IContext<Record<string, unknown>>;
+            symbolTable: ISymbolTable;
+        }): void;
     }
 
     abstract class ElementExpressionCover extends ElementExpression<TData> {
-        abstract evaluate(params: { [key: string]: TData }): void;
+        abstract evaluate(
+            scope: {
+                context: IContext<Record<string, unknown>>;
+                symbolTable: ISymbolTable;
+            },
+            params: { [key: string]: TData }
+        ): void;
     }
 
     setExecutionItem(nodeID);
@@ -86,9 +102,9 @@ export function run(nodeID: string): void {
         const { instance, type, marker } = element;
         if (type === 'Argument') {
             if (instance instanceof ElementDataCover) {
-                instance.evaluate();
+                instance.evaluate(scope);
             } /* instance instanceof ElementExpressionCover */ else {
-                (instance as ElementExpressionCover).evaluate(memo);
+                (instance as ElementExpressionCover).evaluate(scope, memo);
             }
 
             const value = (instance as unknown as ElementArgument<TData>).value;
@@ -98,12 +114,12 @@ export function run(nodeID: string): void {
             }
         } else {
             if (instance instanceof ElementStatement) {
-                instance.onVisit(memo);
+                instance.onVisit(scope, memo);
             } /* instance instanceof ElementBlock */ else {
                 if (marker !== '__rollback__') {
-                    (instance as ElementBlock).onVisit(memo);
+                    (instance as ElementBlock).onVisit(scope, memo);
                 } else {
-                    (instance as ElementBlock).onExit();
+                    (instance as ElementBlock).onExit(scope, {});
                 }
             }
         }

src/execution/scope/index.spec.ts

@@ -3,6 +3,7 @@ import {
     _getSymbolTableManager,
     registerContext,
     deregisterContext,
+    hasContext,
     ScopeStack,
     addGlobalSymbol,
     removeGlobalSymbol,
@@ -39,17 +40,20 @@ describe('Scope Module', () => {
         registerContext('painter', {
             color: 'red',
         });
+        expect(hasContext('painter')).toBe(true);
     });
 
     it('re-registers existing context key-maps by overwriting', () => {
         registerContext('painter', {
             color: 'red',
             width: 4,
         });
+        expect(hasContext('painter')).toBe(true);
     });
 
     it('deregisters context key-maps', () => {
         deregisterContext('painter');
+        expect(hasContext('painter')).toBe(false);
     });
 
     let scopeStack: IScopeStack;

src/execution/scope/index.ts

@@ -67,6 +67,14 @@ export function deregisterContext(name: string): boolean {
     return true;
 }
 
+/**
+ * Returns whether a context is already registered.
+ * @param name context name
+ */
+export function hasContext(name: string): boolean {
+    return name in _contextManagerMap;
+}
+
 /**
  * Adds new global symbol.
  * @param name symbol name

src/index.ts

@@ -57,6 +57,14 @@ export {
 
 export type { TPCOverride } from './@types/execution';
 
+// -- scope ----------------------------------------------------------------------------------------
+
+export type { IContext, ISymbolTable } from './@types/scope';
+
+export { registerContext, deregisterContext, hasContext } from './execution/scope';
+
+// -- interpreter ----------------------------------------------------------------------------------
+
 export {
     declareVariable,
     queryVariable,