index.js

#!/usr/bin/env node

var Insect = require('./output/Insect/index.js');

var insectEnv = Insect.initialEnvironment;

function usage() {
  console.log("Usage:  insect [EXPR]");
  process.exit(1);
}

function runInsect(fmt, line) {
  var lineTrimmed = line.trim();
  if (lineTrimmed === "" || lineTrimmed[0] === "#") {
    return undefined;
  }

  // Run insect
  var res = Insect.repl(fmt)(insectEnv)(line);

  // Update environment
  insectEnv = res.newEnv;

  return res;
}

// Handle command line arguments
if (process.argv.length >= 4) {
  usage();
} else if (process.argv.length == 3) {
  var arg = process.argv[2];
  if (arg === "-h" || arg === "--help") {
    usage();
  } else {
    // Execute a single command
    var res = runInsect(Insect.fmtPlain, arg);
    if (res.msgType === "value" || res.msgType === "info") {
      console.log(res.msg);
    } else if (res.msgType === "error") {
      console.error(res.msg);
    }
    process.exit(0);
  }
}

var interactive = process.stdin.isTTY;

if (interactive) {
  var readline = require('historic-readline');
  var xdgBasedir = require('xdg-basedir');
  var path = require('path');

  // Set up REPL
  var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    path: path.join(xdgBasedir.config, "insect-history"),
    completer: function(line) {
      var identifiers = Insect.identifiers(insectEnv);

      var keywords =
        identifiers.concat(Insect.functions(insectEnv))
                   .concat(Insect.supportedUnits)
                   .concat(Insect.commands);

      var lastWord = line;
      if (line.trim() !== "") {
        var words = line.split(/\b/);
        lastWord = words[words.length - 1];
        keywords= keywords.filter(function(kw) {
          return kw.indexOf(lastWord) === 0;
        });
      }

      return [keywords, lastWord];
    },
    next: function(rl) {
      var prompt = '\x1b[01m>>>\x1b[0m ';

      // The visual length of the prompt (4) needs to be set explicitly for
      // older versions of node:
      rl.setPrompt(prompt, 4);

      rl.prompt();

      rl.on('line', function(line) {
        var res = runInsect(Insect.fmtConsole, line);

        if (res) {
          if (res.msgType == "quit") {
            process.exit(0);
          } else if (res.msgType == "clear") {
            process.stdout.write('\x1Bc');
          } else {
            console.log(res.msg + "\n");
          }
        }

        rl.prompt();
      }).on('close', function() {
        process.exit(0);
      });
    }
  });
} else {
  // Read from non-interactive stream (shell pipe)

  var lineReader = require("line-reader");
  lineReader.eachLine(process.stdin, function(line) {
    var res = runInsect(Insect.fmtPlain, line);
    if (res) {
      // Only output values and halt on errors. Ignore 'info' and 'value-set'
      // message types.
      if (res.msgType === "value") {
        console.log(res.msg);
      } else if (res.msgType == "error") {
        console.error(res.msg);
        process.exit(1);
      } else if (res.msgType == "quit") {
        process.exit(0);
      }
    }
  });
}