Python vs. the Icon programming language

The author had written well over 150,000 lines of Icon when he first learned Python. This comparison is based on relatively little actual experience with Python, and reflects more the author's prejudices in the theory of sound language design.

Advantages of Icon over Python

• The concept of an implicit scan subject is a real timesaver when writing text-processing applications. However, it can be nuisance when verifying programs, because one must keep track of whether any operations have changed the implicit subject. In Python, I've implemented a "Scan object" that implements Icon scanning, but the instances internalize such side effects, making your code easier to verify. See my object library page for Scan and other objects derived from Icon constructs.
• In Icon, you can ask the language to check for undeclared variables. I prefer to have to declare everything, both because it catches many errors resulting from typos, and also because it gives me a place to comment the purpose of each variable.
• I prefer the way Icon implemented built-in variables such as &null. The Python equivalent, None, is not syntactically distinguished from other variables (as the & sets off Icon built-ins). Worse, you can clobber None by storing a value into it! [Note: Python 2.3 and later will warn you if you clobber None.]
• Icon has a single graphics (GUI) interface that works the same across all platforms (or will, once they all get ported). Python has several GUI interfaces, each of which has advantages on specific platforms, and none are as clean and elegant as Icon's.
• The cset type in Icon has no direct equivalent in Python. Accordingly, Python functions such as string.uppercase are biased toward a particular set of characters, while Icon can provide more generalized services. I miss the cset type in text-processing applications.

In the original version of this page, I touted Icon's generators as an advantage. However, generators are now a feature of Python, since Python 2.2.

Advantages of Python over Icon

• Python has a lot more momentum and a much larger and more vigorous user community.
• Python interfaces already exist to a wide variety of systems programming facilities (such as directories and TCP/IP sockets), databases, other languages, and much more.
• Python is much more suitable for embedding (called by other languages) and extending (calling other languages).
• Python is a more object-oriented language. I've done a fair amount of o-o programming in Icon (see my Cleanroom page), but Icon is not an o-o language per se.

Since about 2000 I have not used Icon at all, except to maintain a few legacy applications. The two biggest factors in this choice were the size and universality of Python's library, and the good object model.

Both Python and Icon are freely available and run on a wide variety of platforms.

Last updated: 2005/04/07 21:54:35 UT
URL: http://www.nmt.edu/tcc/help/lang/python/vsicon.html