语句与声明

Grammar

• 简单语句
• 复合语句
• 声明

Runtime

• Completion Record
• Lexical Environment

Completion Record

• [[type]]:normal,break,continue,return or throw
• [[value]]:Types
• [[target]]:label

简单语句

• ExpressionStatement
• EmptyStatement
• DebuggerStatement
• ThrowStatement
• ContinueStatement
• BreakStatement
• ReturnStatement 按顺序如下：

a = 1 + 2;
;
debugger;
throw a;
continue label1;
break label2;
return 1 + 2;

复合语句

• BlockStatement
• IfStatement
• SwitchStatement
• IterationStatement
• WithStatement
• LabelStatement
• TryStatement

//BlockStatement
{
    const a = 2;
}
//IterationStatement
while()
do while()
for( ; ; )
for(let i in {a:2,b:3})
for(let i of [2,3])
//TryStatement
try{
// 非block
throw
}catch( ){

}finally{

}

声明

• FunctionDeclaration
• GeneratorDeclaration
• AsyncFunctionDeclaration
• AsyncGeneratorDeclaration
• VariableStatement
• classDeclaration
• LexicalDeclaration

function foo(){}
let foo = function(){}

function* foo(){
    yield 1;
    yield 2;
}