OpenSPG Schema Mark Language Lexer and Parser, generated by official ANTLR4 grammar.

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Installation

npm install openspg-schema-antlr4

It will be pnpm/yarn add openspg-schema-antlr4 if you use pnpm or yarn.

Usage

Language Parser

• parse(code, [options]): parse() parses the provided code as an entire Schema source unit.
• options:
  • tolerant: boolean, default is false. If true, the parser will try to parse as much as possible, even if the input is invalid, and never throw an error.
  • selector: function, default is (p) => p.sourceUnit(). If provided, the parser will only return the nodes that match the selector. It will be useful when you want to parse a specific node.
• output: SyntaxNode, the root node of the AST.

// parse.mjs
import {parse} from 'openspg-schema-antlr4';

const code = `// Sample
namespace BaiKe

Person(人物): EntityType
    properties:
        desc(描述): Text
            index: TextAndVector
        semanticType(语义类型): SemanticConcept
        synonyms(同义词): Person
        officialName(标准名): Person

Transport(运输): EntityType
    properties:
        desc(描述): Text
            index: TextAndVector
        semanticType(语义类型): SemanticConcept
        synonyms(同义词): Transport
        officialName(标准名): Transport

Works(作品): EntityType
    properties:
        desc(描述): Text
            index: TextAndVector
        semanticType(语义类型): SemanticConcept
        synonyms(同义词): Works
        officialName(标准名): Works

Event(事件): EventType
    properties:
        subject(主体): Person
        participants(参与者): Person
            constraint: MultiValue
        time(时间): Date
        location(地点): GeographicLocation
        abstract(摘要): Text
            index: TextAndVector
        type(事件类型): Text
            index: Text
`;

const ast = parse(code, {tolerant: true, selector: (p) => p.sourceUnit()});

Tokenizer

• tokenizer(code, [options]): tokenizer() parses the provided code as tokens.
• options:
  • tolerant: boolean, default is false.
• output: SyntaxToken[].

// tokenizer.mjs
import {tokenizer} from 'openspg-schema-antlr4';

const tokens = tokenizer(code, {tolerant: true});

Traverse AST

We can use it alongside the parser to traverse nodes.

import {parse, visit, serialize} from 'openspg-schema-antlr4';

const ast = parse(code);

// Use `visit` to traverse ast by enter/exit node type.
visit(ast, {
    enter: ({node, parent}) => {
        console.log(node.type, parent?.type); // print node type
    },
    exit: () => {
    }, // will call when exit node
    Identifier: ({node: identifierNode}) => {
        console.log(identifierNode.name); // print identifier name
    },
    exitContractDefinition: ({node: contractDefinitionNode}) => {
        // will call when exit ContractDefinition node
    }
});

// Use `serialize` to modify ast.
const newAST = serialize(ast, ({node}) => {
    // do something
    if (node.type === 'Identifier') {
        return node.name;
    }
    return node;
})

// traverse.mjs
import {parse, traverse} from 'openspg-schema-antlr4';

const ast = parse(code);

const newAST = traverse(ast, (path) => {
    // path.path => `SourceUnit.Namespace` ...
    // path.node => current node
    // path.parentPath => parent node path
    // path.depth => current node depth
    // path.stop(); => stop traverse
    // path.rewrite({...}); => rewrite current node
    // path.matches({ type: 'xxx' }); => check if current node matches the given filter
    // return () => {}; => will call when exit node
});

Low-level API

Not recommended, but you can use it if you want.

import {SchemaLexer, SchemaParser, CharStream, CommonTokenStream} from 'openspg-schema-antlr4';

const code = `...`; // code here

const input = CharStream.fromString(code);
const lexer = new SolidityLexer(input);
const tokens = new CommonTokenStream(lexer);
const parser = new SolidityParser(tokens);

const parseTree = parser.sourceUnit();

// do something with parseTree

License

Apache