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module salix::demo::basic::Celsius

rascal-0.34.0
salix-core-0.2.3

Usage​

import salix::demo::basic::Celsius;

Source code​

http://github.com/usethesource/salix-core/src/main/rascal/salix/demo/basic/Celsius.rsc

Dependencies​

import salix::App;
import salix::HTML;
import salix::Index;
import String;
import util::Math;
import Exception;

alias Model​

real

data Msg​

data Msg  
     = c(str c)
     | f(str f)
     ;

function celsiusApp​

SalixApp[Model] celsiusApp(str id = "root") 
  = makeApp(id, init, withIndex("C2F", id, view), update);

function celsiusWebApp​

App[Model] celsiusWebApp() 
  = webApp(
      celsiusApp(),
      |project://salix/src/main/rascal|
    );

function init​

Model init() = 37.0;

function view​

void view(Model m) {   
    h2("Celsius to fahrenheit converter");
    p(() {
      text("C: "); 
      input(\value("<round(m)>"),\type("number"), onInput(c));
    });
    p(() {
      text("F: ");
      input(\value("<round(toF(m))>"),\type("number"), onInput(f));
    });
}

function toF​

real toF(real c) = c * 9.0/5.0 + 32.0;

function toC​

real toC(real f) = (f - 32.0) * 5.0/9.0;

function toReal {#salix-demo-basic-Celsius-toReal}​

real toReal_(str s) {
  try {
    return toReal(s);
  }
  catch IllegalArgument():
    return 0.0;
}

function update​

real update(Msg msg, Model model) {
  switch (msg) {
    case c(str new): model = toReal_(new);
    case f(str new): model = toC(toReal_(new));
  }
  return model;
}