buffer-apg-js/src/apg-api/scanner-callbacks.js

JavaScript APG, an ABNF Parser Generator

/*  *************************************************************************************
 *   copyright: Copyright (c) 2021 Lowell D. Thomas, all rights reserved
 *     license: BSD-2-Clause (https://opensource.org/licenses/BSD-2-Clause)
 *   ********************************************************************************* */
// These are the AST translation callback functions used by the scanner
// to analyze the characters and lines.
const ids = require('../apg-lib/identifiers');
const utils = require('../apg-lib/utilities');

function semLine(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.endLength = 0;
    data.textLength = 0;
    data.invalidCount = 0;
  } else {
    data.lines.push({
      lineNo: data.lines.length,
      beginChar: phraseIndex,
      length: phraseCount,
      textLength: data.textLength,
      endType: data.endType,
      invalidChars: data.invalidCount,
    });
  }
  return ids.SEM_OK;
}
function semLineText(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.textLength = phraseCount;
  }
  return ids.SEM_OK;
}
function semLastLine(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.endLength = 0;
    data.textLength = 0;
    data.invalidCount = 0;
  } else if (data.strict) {
    data.lines.push({
      lineNo: data.lines.length,
      beginChar: phraseIndex,
      length: phraseCount,
      textLength: phraseCount,
      endType: 'none',
      invalidChars: data.invalidCount,
    });
    data.errors.push({
      line: data.lineNo,
      char: phraseIndex + phraseCount,
      msg: 'no line end on last line - strict ABNF specifies CRLF(\\r\\n, \\x0D\\x0A)',
    });
  } else {
    /* add a line ender */
    chars.push(10);
    data.lines.push({
      lineNo: data.lines.length,
      beginChar: phraseIndex,
      length: phraseCount + 1,
      textLength: phraseCount,
      endType: 'LF',
      invalidChars: data.invalidCount,
    });
  }
  return ids.SEM_OK;
}
function semInvalid(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.errors.push({
      line: data.lineNo,
      char: phraseIndex,
      msg: `invalid character found '\\x${utils.charToHex(chars[phraseIndex])}'`,
    });
  }
  return ids.SEM_OK;
}
function semEnd(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_POST) {
    data.lineNo += 1;
  }
  return ids.SEM_OK;
}
function semLF(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.endType = 'LF';
    if (data.strict) {
      data.errors.push({
        line: data.lineNo,
        char: phraseIndex,
        msg: 'line end character LF(\\n, \\x0A) - strict ABNF specifies CRLF(\\r\\n, \\x0D\\x0A)',
      });
    }
  }
  return ids.SEM_OK;
}
function semCR(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.endType = 'CR';
    if (data.strict) {
      data.errors.push({
        line: data.lineNo,
        char: phraseIndex,
        msg: 'line end character CR(\\r, \\x0D) - strict ABNF specifies CRLF(\\r\\n, \\x0D\\x0A)',
      });
    }
  }
  return ids.SEM_OK;
}
function semCRLF(state, chars, phraseIndex, phraseCount, data) {
  if (state === ids.SEM_PRE) {
    data.endType = 'CRLF';
  }
  return ids.SEM_OK;
}
const callbacks = [];
callbacks.line = semLine;
callbacks['line-text'] = semLineText;
callbacks['last-line'] = semLastLine;
callbacks.invalid = semInvalid;
callbacks.end = semEnd;
callbacks.lf = semLF;
callbacks.cr = semCR;
callbacks.crlf = semCRLF;
exports.callbacks = callbacks;