add syntax sugar to support JSON array/object value

[rosbit]

because awk doesn't support literal JSON object, it is very tedious to create an array variable like this:

   a["f1"] = 1
   a["f2"] = 2
   a["f3"] = 3

I added two syntax sugars to write literal JSON object. The changes includes:

1. add a keyword "var" to indicate the following NAME is an array variable name
2. add some tokens, they are "true", "false", F_JARRAY, F_JOBJECT
3. F_JARRAY and J_OBJECT are implemented as built-in functions to wrapper arguments to array values
4. expand value struct in interp package to support value type "map[string]value"

now we can write literal JSON object in awk like the following:

  var a = {
       f1: 1, f2: 2, f3:3,
       "a": true, "b": [1, 3, 4]
  }

and we can refer the variable by index like
print a["f1"]

If you think this is useful, merge it to the master trunk. Thank you!

Rosbit Xu.

[benhoyt]

Hi @rosbit, this is a nice idea. However, I'd like to keep GoAWK close to awk and the POSIX AWK spec, and not add arbitrary features beyond that, so unfortunately I won't be including this.