Proofscape-flavored JSON#

In Proofscape modules, assignment values are given in a relaxed and generalized form of JSON, which we call “Proofscape-flavored JSON,” or PF-JSON for short. PF-JSON is also used when defining the values of DATA fields in Widgets.


In PF-JSON, strings are largely like those in the Python programming language, in that:

  • Four different delimiters are allowed:
    • """ (triple double quotes)

    • ''' (triple single quotes)

    • " (double quotes)

    • ' (single quotes)

  • Inside double-quoted strings, the delimiter can occur if escaped, as in \".

  • Inside single-quoted strings, the delimiter can occur if escaped, as in \'.

However, strings in Proofscape modules differ from those in Python in that:

  • Any type of string, including double-quoted (") and single-quoted ('), may span multiple lines, i.e. may contain newline characters.

Unquoted keys#

As in JavaScript, when objects are given by key-value pairs, the keys may be given by strings with quotation marks around them, or the quotation marks may be omitted when the contents are of a particularly simple form; namely, when they consist only of alphanumerics and underscores, and when the first character is not a digit.


    "foo": 42,
    bar: 43

Trailing commas#

When you write a list or object, you may include a trailing comma after the last entry.


    foo: [42, 84,],
    bar: null,


A libpath is a valid primitive, along with the usual primitives, i.e. strings, integers, floats, and the constants true, false, and null.


Listing 78 Using a libpath as a primitive#
from ... import Pf

foo = {
    great_proof: true,
    favorite_node: Pf.A10,

In Listing 78, the libpath Pf.A10 is used as a primitive. (In particular, it is not a string, since it is not surrounded by quotation marks of any kind.)

Note: It is because libpaths can be used as primitives in PF-JSON, that true, false, and null are illegal libpath segments (see Libpaths) in order to avoid collisions.