IF Handlebars helpers

if.coffee

    handlebars_helpers: () ->
      Handlebars.registerHelper 'ifbool', (b, c) ->
        if b then do c.fn else do c.inverse

      Handlebars.registerHelper 'ifequal', (l, r, c) ->
        if l is r then do c.fn else do c.inverse

      Handlebars.registerHelper 'unlessequal', (l, r, c) ->
        unless l is r then do c.fn else do c.inverse

      Handlebars.registerHelper 'ifcompare', (l, r, o) ->
        operator = o.hash.operator || "=="
        operators =
          '==': (l,r) -> l == r
          '===': (l,r) -> l is r
          '!=': (l,r) -> l != r
          '<': (l,r) -> l < r
          '>': (l,r) -> l > r
          '<=': (l,r) -> l <= r
          '>=': (l,r) -> l >= r
          'typeof': (l,r) -> typeof l == r

        if arguments.length < 3 then throw new Error "Handlerbars Helper 'compare' needs 2 parameters"
        unless operators[operator] then throw new Error "Handlerbars Helper 'compare' doesn't know the operator #{operator}"

        if operators[operator](l, r) then o.fn @
        else o.inverse @