How to Extract AST of given Typescript code using the open source Typescript compiler code?

问题

As it is known that Typescript is completely opensource now. which is available at Tyescript. I am building an application that will get Typescript code as input and give output the AST of the given code. Provide me a proper way to extract this AST(Abstract Syntax Tree) of input Typescript code rather than comppliling it and converting it into Javascript.

回答1:

Basic code:

const fileNames = ["C:\\MyFile.ts"];
const compilerOptions: ts.CompilerOptions = {
    // compiler options go here if any...
    // look at ts.CompilerOptions to see what's available
};
const program = ts.createProgram(fileNames, compilerOptions);
const typeChecker = program.getTypeChecker();
const sourceFiles = program.getSourceFiles();

sourceFiles.filter(f => /MyFile\.ts$/.test(f.fileName)).forEach(sourceFile => {
    ts.forEachChild(sourceFile, node => {
        const declaration = node as ts.Declaration;
        if (declaration.name) {
            console.log(declaration.name.getText());
        }
    });
});

So if you provided that with a C:\MyFile.ts like:

class MyClass {}
interface MyInterface {}

It would output MyClass and MyInterface.

Figuring out everything beyond what I've just shown is a lot of work. It might be more beneficial for you to look at and/or help contribute to this work in progress.

回答2:

TypeScript compiler doesn't support it but you can do it using recast and babylon@next. Although you will have to trust in the syntax defined by these technologies for representing TypeScript code AST and that they will keep up to date - since TypeScript has new language features release by release (short period of time) - is not like other languages (JavaScript) where you have well defined versions and released in a standard - so if your users start using new language features these technologies (mostly babylon) should keep up to date:

// npm install recast babylon@next
const source = `
interface I {
  color: string
}
class C implements I{
  color: string='blue'
}
`
const recast = require('recast')
const tsParser = require("recast/parsers/typescript")
const ast = recast.parse(source, {
  parser: tsParser
});
console.log(`
CODE: 

${source}

AST: 

${JSON.stringify(ast)}
`);

来源：https://stackoverflow.com/questions/36505533/how-to-extract-ast-of-given-typescript-code-using-the-open-source-typescript-com

标签

typescript

abstract-syntax-tree