Remove `alias` statement, prefer `model =`

packages/adl/compiler/parser.ts

@@ -41,11 +41,6 @@ export function parse(code: string) {
           return parseModelStatement(decorators);
         case Kind.InterfaceKeyword:
           return parseInterfaceStatement(decorators);
-        case Kind.AliasKeyword:
-          if (decorators.length > 0) {
-            error('Cannot decorate an alias statement');
-          }
-          return parseAliasStatement();
         case Kind.Semicolon:
           if (decorators.length > 0) {
             error('Cannot decorate an empty statement');
@@ -550,23 +545,6 @@ export function parse(code: string) {
     }, pos);
   }
 
-  function parseAliasStatement(): Types.AliasStatementNode {
-    const pos = tokenPos();
-    parseExpected(Kind.AliasKeyword);
-
-    const id = parseIdentifier();
-    parseExpected(Kind.Colon);
-
-    const target = parseExpression();
-    parseExpected(Kind.Semicolon);
-
-    return finishNode({
-      kind: Types.SyntaxKind.AliasStatement,
-      id,
-      target
-    }, pos);
-  }
-
   // utility functions
   function token() {
     return scanner.token;
@@ -668,9 +646,6 @@ export function visitChildren<T>(node: Types.Node, cb: NodeCb<T>): T | undefined
   switch (node.kind) {
     case Types.SyntaxKind.ADLScript:
       return visitEach(cb, (<Types.ADLScriptNode>node).statements);
-    case Types.SyntaxKind.AliasStatement:
-      return visitNode(cb, (<Types.AliasStatementNode>node).id) ||
-        visitNode(cb, (<Types.AliasStatementNode>node).target);
     case Types.SyntaxKind.ArrayExpression:
       return visitNode(cb, (<Types.ArrayExpressionNode>node).elementType);
     case Types.SyntaxKind.DecoratorExpression:

packages/adl/compiler/scanner.ts

@@ -121,7 +121,6 @@ export enum Kind {
   ImportKeyword,
   ModelKeyword,
   InterfaceKeyword,
-  AliasKeyword,
   TrueKeyword,
   FalseKeyword
 }
@@ -130,7 +129,6 @@ const keywords = new Map([
   ['import', Kind.ImportKeyword],
   ['model', Kind.ModelKeyword],
   ['interface', Kind.InterfaceKeyword],
-  ['alias', Kind.AliasKeyword],
   ['true', Kind.TrueKeyword],
   ['false', Kind.FalseKeyword]
 ]);

packages/adl/compiler/types.ts

@@ -122,7 +122,6 @@ export enum SyntaxKind {
   StringLiteral,
   NumericLiteral,
   BooleanLiteral,
-  AliasStatement,
   TemplateApplication,
   TemplateParameterDeclaration
 }
@@ -142,8 +141,7 @@ export interface ADLScriptNode extends Node {
 export type Statement =
   | ImportStatementNode
   | ModelStatementNode
-  | InterfaceStatementNode
-  | AliasStatementNode;
+  | InterfaceStatementNode;
 
 export interface ImportStatementNode extends Node {
   kind: SyntaxKind.ImportStatement;
@@ -271,12 +269,6 @@ export interface IntersectionExpressionNode extends Node {
   options: Array<Expression>;
 }
 
-export interface AliasStatementNode extends Node {
-  kind: SyntaxKind.AliasStatement;
-  id: IdentifierNode;
-  target: Expression;
-}
-
 export interface TemplateApplicationNode extends Node {
   kind: SyntaxKind.TemplateApplication;
   target: Expression;

packages/adl/language.grammar

@@ -25,7 +25,6 @@ Keyword :
     `import`
     `model`
     `interface`
-    `alias`
 
 Identifier :
     IdentifierName but not Keyword
@@ -182,7 +181,6 @@ StatementList :
 
 Statement :
     ImportStatement
-    AliasStatement
     ModelStatement
     InterfaceStatement
 
@@ -194,9 +192,6 @@ NamedImports :
     Identifier
     NamedImports `,` Identifier
 
-AliasStatement :
-    `alias` Identifier `:` Expression `;`
-
 ModelStatement :
     DecoratorList? `model` Identifier `{` ModelBody? `}`
     DecoratorList? `model` Identifier `=` Expression `;`

packages/adl/language.md

@@ -22,7 +22,6 @@
 &emsp;&emsp;&emsp;<a name="Keyword-0330acf5"></a>`` import ``  
 &emsp;&emsp;&emsp;<a name="Keyword-fa60d604"></a>`` model ``  
 &emsp;&emsp;&emsp;<a name="Keyword-ef54526d"></a>`` interface ``  
-&emsp;&emsp;&emsp;<a name="Keyword-921cc095"></a>`` alias ``  
   
 &emsp;&emsp;<a name="Identifier"></a>*Identifier* **:**  
 &emsp;&emsp;&emsp;<a name="Identifier-11758399"></a>*[IdentifierName](#IdentifierName)* **but not** *[Keyword](#Keyword)*  
@@ -168,7 +167,6 @@
   
 &emsp;&emsp;<a name="Statement"></a>*Statement* **:**  
 &emsp;&emsp;&emsp;<a name="Statement-648ff91f"></a>*[ImportStatement](#ImportStatement)*  
-&emsp;&emsp;&emsp;<a name="Statement-0d99421b"></a>*[AliasStatement](#AliasStatement)*  
 &emsp;&emsp;&emsp;<a name="Statement-3606dce2"></a>*[ModelStatement](#ModelStatement)*  
 &emsp;&emsp;&emsp;<a name="Statement-a875a11d"></a>*[InterfaceStatement](#InterfaceStatement)*  
   
@@ -180,9 +178,6 @@
 &emsp;&emsp;&emsp;<a name="NamedImports-06b6ace8"></a>*[Identifier](#Identifier)*  
 &emsp;&emsp;&emsp;<a name="NamedImports-02b3b1dc"></a>*[NamedImports](#NamedImports)*&emsp;`` , ``&emsp;*[Identifier](#Identifier)*  
   
-&emsp;&emsp;<a name="AliasStatement"></a>*AliasStatement* **:**  
-&emsp;&emsp;&emsp;<a name="AliasStatement-d918b509"></a>`` alias ``&emsp;*[Identifier](#Identifier)*&emsp;`` : ``&emsp;*[Expression](#Expression)*&emsp;`` ; ``  
-  
 &emsp;&emsp;<a name="ModelStatement"></a>*ModelStatement* **:**  
 &emsp;&emsp;&emsp;<a name="ModelStatement-b7b1d16b"></a>*[DecoratorList](#DecoratorList)*<sub>opt</sub>&emsp;`` model ``&emsp;*[Identifier](#Identifier)*&emsp;`` { ``&emsp;*[ModelBody](#ModelBody)*<sub>opt</sub>&emsp;`` } ``  
 &emsp;&emsp;&emsp;<a name="ModelStatement-a9aaf94c"></a>*[DecoratorList](#DecoratorList)*<sub>opt</sub>&emsp;`` model ``&emsp;*[Identifier](#Identifier)*&emsp;`` = ``&emsp;*[Expression](#Expression)*&emsp;`` ; ``  

packages/adl/test/test-parser.ts

@@ -155,14 +155,6 @@ describe('syntax', () => {
     ]);
   });
 
-  describe('alias statements', () => {
-    parseEach([
-      'alias MyAlias : SomethingElse;',
-      'alias MyAlias : { constantProperty: 4 };',
-      'alias MyAlias : [ string, number ];'
-    ]);
-  });
-
   describe('multiple statements', () => {
     parseEach([`
       model A { };