Python

Python is a popular scripting language that was first released in 1991. This article compares Python to MiniScript, and may be useful to people coming to MiniScript with a background in Python.

For a side-by-side comparison on a bunch of short programs, see here.

Similarities

Data Types

MiniScript's six data types have direct analogs to common types in Python:

• Numbers in MiniScript are double-precision floating point numbers, equivalent to Python's numbers.Real (aka float) data type. Note that in MiniScript, False and True are represented directly by the numbers 0 and 1; there is no separate bool type.

• Strings in both languages are an immutable sequence of Unicode code points. String literals in both languages can be enclosed in double-quotes; MiniScript does not have the optional single-quote or triple-quote syntax. While Python uses backslash-escaping to include a quotation mark within a literal, in MiniScript you just write the quotation mark twice, as in SQL.

• Lists in both languages are a mutable sequence of arbitrary values; a list literal uses square brackets surrounding comma-delimited values (see List Syntax, below). Note that MiniScript does not have a tuple type, and uses a list in situations where Python might use a tuple.

• Maps in both languages are mutable, unordered set of key-value pairs, with the same literal syntax (see Map Syntax and Object-Oriented Programming, below).

• Function objects in both languages are similar: first-class, callable objects. However functions in MiniScript have no attributes, and the syntax for defining functions is somewhat different.

• null is a special datatype in both languages, representing a null reference.

List Syntax

The syntax for list literals is the same in Python and MiniScript: a series of arbitrary values, separated by commas and surrounded by square brackets.

myList = ["apple", "banana", "cherry", "date"]

Index and slice syntax is also the same in both, except that MiniScript slicing supports only two parameters; it does not support the third (IndexJump) parameter.

myList[0]     // "apple"
myList[:2]    // ["apple", "banana"]
myList[-3:]   // ["banana", "cherry", "date"]
myList[1:-1]  // ["banana", "cherry"]
myList[:]     // independent copy of ["apple", "banana", "cherry", "date"]

Unlike Python, you cannot assign to a slice; you can only assign to a single index.

myList[1] = "orange"  // myList is now: ["apple", "orange", "cherry", "date"]
myList[1:3] = ["lemon"]   // DOES NOT WORK

Map Syntax

The syntax for map literals and map indexing is the same in Python and MiniScript:

m = {"one":1, "two":2, "three":3}
print m["two"]   // 2
m["pi"] = 3.14

Unlike Python, in MiniScript when a key in a map happens to also be a valid literal, it can be accessed via dot syntax.

print m.two  // 2
m.pi = 3.14157

MiniScript does not have a concept of "attributes" as something separate from key/value pairs in a map.

Variable Scope

Variables in both Python and MiniScript are local by default. There are some subtle differences, however: in Python, an inner function can implicitly access the variables of an outer function, but can't implicitly access global variables, while in MiniScript, any function can implicitly read values from both the outer context and the global context. To update a global variable, where Python uses a special global statement, MiniScript uses a globals prefix in a manner similar to using self to access object data.

(ToDo: example)

Object-Oriented Programming

Both MiniScript and Python support object-oriented programming, with some similarities and some differences. MiniScript uses prototype-based inheritance, where the difference between "class" and "instance" is mainly in the mind of the programmer. Classes/instances are just maps, with the inheritance chain stored in a special __isa entry that is automatically set by the new operator.

Similarities between MiniScript and Python:

• inheritance and polymorphism
• use of self and super

Differences in MiniScript, as compared to Python:

• prototype-based inheritance built on classes
• use of new to subclass or create an instance
• no constructors
• no operator overloading or other magic methods

This MiniScript example illustrates some of these similarities and differences:

Person = {}   // any empty map can be considered a class
Person.init = function(name, age)  // not a magic method; just an ordinary method
    self.name = name   // note use of self (an implicit parameter)
    self.age = age
end function

Person.sayHello = function
    print "Hello world!"
end function

Person.sayName = function
    print "My name is " + self.name + "."
end function

CoolPerson = new Person    // creating a "subclass" of Person
CoolPerson.sayHello = function    // overriding a function
    print "How you doin'?"
end function

Joey = new CoolPerson      // creating an "instance" of CoolPerson
Joey.init "Joey", 28
Joey.sayHello   // prints: How you doin'?
Joey.sayName    // prints: My name is Joey.

Differences

Language Scale

MiniScript is a considerably smaller language by any reasonable measure. For example, the following table compares Python and MiniScript on C/C++ source code lines, source code files, number of data types, and number of standard intrinsic functions, as of 2021 (source).

	Python	MiniScript
Source Lines	661,775	13,752
Source Files	718	46
Data Types	34	6
Intrinsics	69	53

Block Syntax

The most obvious difference between Python and MiniScript is in block syntax. While Python defines blocks by ending the opening line with a colon, and indenting the body of the block, MiniScript uses keyword pairs like if/end if, for/end for, and function/end function (more similar to Visual Basic). Indentation in MiniScript is strictly cosmetic, and is ignored by the compiler; and tools can automatically standardize or re-indent based on the keywords.

Python	MiniScript
def myfunc(): for i in range(1, 11): if i == 9: print("Almost done...") else: print(i) myfunc()	myFunc = function for i in range(1, 10) if i == 9 then print "Almost done..." else print i end if end for end function myFunc

Function Invocation

While functions in Python are always invoked by putting parentheses after a function reference, in MiniScript, such parentheses can be omitted when (1) the function call is the entire statement, or (2) there are no arguments.

Python	MiniScript
import random x = random.uniform(0,1) print(x)	x = rnd print x

Magic Methods and Attributes

Python uses a large number of "magic" (aka "dunder") methods and attributes which have special meaning to the interpreter. These support things like operator overloading (__add__, __ne__, etc.), class support (__class__, __subclasshook__), and documentation (__doc__). By implementing these methods or assigning to these attributes, you can substantially change the way instances of a class behave.

MiniScript has no such magic methods or attributes, with the exception of the __isa key used to track inheritance in maps. __isa is automatically set by new and used by the isa operator, so in most cases user code should not ever need to touch it.

MiniScript does not support any form of operator overloading, or hooks to intercept other aspects of object behavior; objects always behave the same way.

import

While not part of the core language, several MiniScript environments (including Mini Micro, Soda, command-line MiniScript, and Farmtronics) support an import command. However the semantics are a bit different from Python.

In MiniScript, the module name must be a string (usually, a string literal). The import command searches for a corresponding script file, runs it in its own call context, and binds the result (as a map) to an identifier of the same name in the calling context.

import "mathUtil"
print mathUtil.dice(3,6)    // rolls 3d6 and prints the result

Note that import always runs the code in the imported module, even if it was run before. See the Usage Notes under import for an ensureImport function that may be helpful to ensure a module is imported only once.

MiniScript does not support the from syntax (e.g. Python's from math import pi or from math import *).

range function

The very common built-in function range in both languages takes up to three arguments: start, stop, and step. But there are a few differences to note:

• In Python, the stop value is not included in the resulting sequence, while in MiniScript it is (i.e., it is an inclusive bound).
• In Python, if stop is less than start, the result is an empty list unless you also specify a negative step. In MiniScript, if step is omitted in such a case, it defaults to -1 (and you get a list that counts down).
• In Python, if only one argument is given, it is considered stop and the resulting sequence counts from 0 up to (but not including) that value. In MiniScript, a single argument is start and the resulting sequence counts from that number down (or up) to 0.
• In Python, the result of range is a range object; in MiniScript it is an ordinary list.