codeWriter.js

/**
 Copyright 2014 Gordon Williams (gw@pur3.co.uk)

 This Source Code is subject to the terms of the Mozilla Public
 License, v2.0. If a copy of the MPL was not distributed with this
 file, You can obtain one at http://mozilla.org/MPL/2.0/.

 ------------------------------------------------------------------
  The plugin that actually writes code out to Espruino
 ------------------------------------------------------------------
**/
"use strict";
(function(){

  function init() {
    Espruino.Core.Config.add("RESET_BEFORE_SEND", {
      section : "Communications",
      name : "Reset before Send",
      description : "Reset Espruino before sending code from the editor pane?",
      type : "boolean",
      defaultValue : true
    });
    Espruino.Core.Config.add("STORE_LINE_NUMBERS", {
      section : "Communications",
      name : "Store line numbers",
      description : "Should Espruino store line numbers for each function? This uses one extra variable per function, but allows you to get source code debugging in the Web IDE",
      type : "boolean",
      defaultValue : true
    });

  }

  function writeToEspruino(code, callback) {
    /* hack around non-K&R code formatting that would have
    broken Espruino CLI's bracket counting */
    code = reformatCode(code);
    if (code === undefined) return; // it should already have errored

    // We want to make sure we've got a prompt before sending. If not,
    // this will issue a Ctrl+C
    Espruino.Core.Utils.getEspruinoPrompt(function() {
      // Make sure code ends in 2 newlines
      while (code[code.length-2]!="\n" || code[code.length-1]!="\n")
        code += "\n";

      // By sending an empty print, we remove the Espruino '>' prompt
      // which then allows us to see if upload has finished
      code = "\x10print()\n"+code;
      // If we're supposed to reset Espruino before sending...
      if (Espruino.Config.RESET_BEFORE_SEND) {
        // reset Espruino
        code = "\x10reset();\n"+code;
      }

      //console.log("Sending... "+data);
      Espruino.Core.Serial.write(code, true, function() {
        // give 5 seconds for sending with save and 2 seconds without save
        var count = Espruino.Config.SAVE_ON_SEND ? 50 : 20;
        setTimeout(function cb() {
          if (Espruino.Core.Terminal!==undefined &&
              !Espruino.Core.Terminal.getTerminalLine().startsWith(">")) {
            count--;
            if (count>0) {
              setTimeout(cb, 100);
            } else {
              Espruino.Core.Notifications.error("Prompt not detected - upload failed. Trying to recover...");
              Espruino.Core.Serial.write("\x03\x03echo(1)\n", false, callback);
            }
          } else {
            if (callback) callback();
          }
        }, 100);
      });
    });
  }

  /**
   * Parse and fix issues like `if (false)\n foo` in the root scope
   * @param {string} code 
   * @returns {string | undefined}
   */
  function reformatCode(code) {
    var APPLY_LINE_NUMBERS = false;
    var lineNumberOffset = 0;
    var ENV = Espruino.Core.Env.getData();
    if (ENV && ENV.VERSION_MAJOR && ENV.VERSION_MINOR) {
      if (ENV.VERSION_MAJOR>1 ||
          ENV.VERSION_MINOR>=81.086) {
        if (Espruino.Config.STORE_LINE_NUMBERS)
          APPLY_LINE_NUMBERS = true;
      }
    }
    /* There's only any point writing line numbers when we're saving to RAM. Otherwise we just
    end up applying line numbers to require("Storage").write lines. see https://github.com/espruino/EspruinoTools/pull/179 */
    if (Espruino.Config.SAVE_ON_SEND != 0) {
      APPLY_LINE_NUMBERS = false;
    }
    // Turn cr/lf into just lf (eg. windows -> unix)
    code = code.replace(/\r\n/g,"\n");
    // First off, try and fix funky characters
    for (let i=0;i<code.length;i++) {
      var ch = code.charCodeAt(i);
      if ((ch<32 || ch>255) && ch!=9/*Tab*/ && ch!=10/*LF*/ && ch!=13/*CR*/) {
        console.warn("codewriter> Unexpected character code "+ch+" at position "+i+". Replacing with ?");
        code = code.substr(0,i)+"?"+code.substr(i+1);
      }
    }

    /* Search for lines added to the start of the code by the module handler.
    Ideally there would be a better way of doing this so line numbers stayed correct,
    but this hack works for now. Fixes EspruinoWebIDE#140 */
    if (APPLY_LINE_NUMBERS) {
      var l = code.split("\n");
      let i = 0;
      while (l[i] && (l[i].substr(0,8)=="Modules." ||
                      l[i].substr(0,8)=="setTime(")) i++;
      lineNumberOffset = -i;
    }

    var resultCode = "\x10"; // 0x10 = echo off for line
    /** we're looking for:
     *   `a = \n b`
     *   `for (.....) \n X`
     *   `if (.....) \n X`
     *   `if (.....) { } \n else foo`
     *   `while (.....) \n X`
     *   `do \n X`
     *   `function (.....) \n X`
     *   `function N(.....) \n X`
     *   `var a \n , b`    `var a = 0 \n, b`
     *   `var a, \n b`     `var a = 0, \n b`
     *   `a \n . b`
     *   `foo() \n . b`
     *   `try { } \n catch \n () \n {}`
     *
     *   These are divided into two groups - where there are brackets
     *   after the keyword (statementBeforeBrackets) and where there aren't
     *   (statement)
     *
     *   We fix them by replacing \n with what you get when you press
     *   Alt+Enter (Ctrl + LF). This tells Espruino that it's a newline
     *   but NOT to execute.
     */
    var lex = Espruino.Core.Utils.getLexer(code);
    var brackets = 0;
    var curlyBrackets = 0;
    var statementBeforeBrackets = false;
    var statement = false;
    var varDeclaration = false;
    var lastIdx = 0;
    var lastTok = {str:""};
    var tok = lex.next();
    while (tok!==undefined) {
      var previousString = code.substring(lastIdx, tok.startIdx);
      var tokenString = code.substring(tok.startIdx, tok.endIdx);
      //console.log("codewriter> prev "+JSON.stringify(previousString)+"   next "+tokenString);

      /* Inserting Alt-Enter newline, which adds newline without trying
      to execute */
      if (brackets>0 || // we have brackets - sending the alt-enter special newline means Espruino doesn't have to do a search itself - faster.
          statement || // statement was before brackets - expecting something else
          statementBeforeBrackets ||  // we have an 'if'/etc
          varDeclaration || // variable declaration then newline
          tok.str=="," || // comma on newline - there was probably something before
          tok.str=="." || // dot on newline - there was probably something before
          tok.str=="+" || tok.str=="-" || // +/- on newline - there was probably something before
          tok.str=="=" || // equals on newline - there was probably something before
          tok.str=="else" || // else on newline
          lastTok.str=="else" || // else befgore newline
          tok.str=="catch" || // catch on newline - part of try..catch
          lastTok.str=="catch"
        ) {
        //console.log("codewriter> Possible"+JSON.stringify(previousString));
        previousString = previousString.replace(/\n/g, "\x1B\x0A");
      }

      var previousBrackets = brackets;
      if (tok.str=="(" || tok.str=="{" || tok.str=="[") brackets++;
      if (tok.str=="{") curlyBrackets++;
      if (tok.str==")" || tok.str=="}" || tok.str=="]") brackets--;
      if (tok.str=="}") curlyBrackets--;

      if (brackets==0) {
        if (tok.str=="for" || tok.str=="if" || tok.str=="while" || tok.str=="function" || tok.str=="throw") {
          statementBeforeBrackets = true;
          varDeclaration = false;
        } else if (tok.str=="var") {
          varDeclaration = true;
        } else if (tok.type=="ID" && lastTok.str=="function") {
          statementBeforeBrackets = true;
        } else if (tok.str=="try" || tok.str=="catch") {
          statementBeforeBrackets = true;
        } else if (tok.str==")" && statementBeforeBrackets) {
          statementBeforeBrackets = false;
          statement = true;
        } else if (["=","^","&&","||","+","+=","-","-=","*","*=","/","/=","%","%=","&","&=","|","|="].indexOf(tok.str)>=0) {
          statement = true;
        } else {
          if (tok.str==";") varDeclaration = false;
          statement = false;
          statementBeforeBrackets = false;
        }
      }
      /* If we're at root scope and had whitespace/comments between code,
      remove it all and replace it with a single newline and a
      0x10 (echo off for line) character. However DON'T do this if we had
      an alt-enter in the line, as it was there to stop us executing
      prematurely */
      if (previousBrackets==0 &&
          previousString.indexOf("\n")>=0 &&
          previousString.indexOf("\x1B\x0A")<0) {
        previousString = "\n\x10";
        // Apply line numbers to each new line sent, to aid debugger
        if (APPLY_LINE_NUMBERS && tok.lineNumber && (tok.lineNumber+lineNumberOffset)>0) {
          // Esc [ 1234 d
          // This is the 'set line number' command that we're abusing :)
          previousString += "\x1B\x5B"+(tok.lineNumber+lineNumberOffset)+"d";
        }
      }

      // add our stuff back together
      resultCode += previousString+tokenString;
      // next
      lastIdx = tok.endIdx;
      lastTok = tok;
      tok = lex.next();
    }
    //console.log(resultCode);
    if (brackets>0) {
      Espruino.Core.Notifications.error("You have more open brackets than close brackets. Please see the hints in the Editor window.");
      return undefined;
    }
    if (brackets<0) {
      Espruino.Core.Notifications.error("You have more close brackets than open brackets. Please see the hints in the Editor window.");
      return undefined;
    }
    return resultCode;
  }

  Espruino.Core.CodeWriter = {
    init : init,
    writeToEspruino : writeToEspruino, // call this to send to Espruino
    reformatCode : reformatCode  // Parse and fix issues like `if (false)\n foo` in the root scope
  };
}());