bnf-parser

import * as fs from 'node:fs'; import * as path from 'node:path'; import { execSync } from 'node:child_process'; // 1. Define your BNF grammar const bnfContent = `program ::= chunk+ ; chunk ::= "a"+ "b"+ ;`; const bnfFilePath = path.join(process.cwd(), 'syntax.bnf'); fs.writeFileSync(bnfFilePath, bnfContent); // 2. Compile the BNF to a WebAssembly parser using the CLI // This is typically run as a build step or dev script try { console.log('Compiling BNF...'); execSync(`npx bnf-compile ${bnfFilePath} --outDir ./bnf-output`, { stdio: 'inherit' }); console.log('Compilation successful!'); } catch (error) { console.error('BNF compilation failed:', error.message); process.exit(1); } // 3. Import and use the generated parser // The path should match your --outDir and BNF file name import('./bnf-output/syntax.js').then(syntax => { const inputString = "abbaabab"; console.log(`Parsing input: "${inputString}"`); const tree = syntax.Parse_Program(inputString).root; console.log('Parsed AST:', JSON.stringify(tree, null, 2)); const firstChunk = tree.value[0]; if (firstChunk && firstChunk.type === 'Term_chunk') { console.log(`Type of first chunk: ${firstChunk.type}`); const firstBs = firstChunk.value[1]; // Assuming chunk is ['a+', 'b+'] if (firstBs && Array.isArray(firstBs.value)) { const bCount = firstBs.value.length; console.log(`Count of 'b's in the first 'b+' sequence: ${bCount}`); } } }).catch(error => { console.error('Failed to import or use generated parser:', error); });