This document is an informal collection of design ideas for the Halcyon programming language. This document in in permanent draft status; do not take anything you read here as final. There are no plans to ever actually implement the ideas here; they're listed only for future reference.
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Static, strong typing
Type errors at runtime are stupid.
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Type inference
Having to type types that the compiler knows is stupid.
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First-class monadish things
Something along the lines of F# computation expressions. I think I'll call them "environments".
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Compile-time metaprogramming/code generation
Syntactic and semantic manipulations are cool. I'm thinking of stuff along the lines of boo's syntactic macros, AST attributes and metafunctions; not along the lines of Ruby-style metaprogramming or C++ template metaprogramming.
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Proper Unicode support
"Are Halcyon strings UTF-8 or UTF-16?" is a question that makes no sense. Halcyon strings are sequences of codepoints, not code units. By that I don't mean they're UTF-32; saying they're UTF-32 makes as much sense as the question above: zero.
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Proper iteration
Only three loops are needed: while, do-while, and Python-like for-in. C#-like iterators or Python-like generators or any other yield-like construct does wonders with for-in.
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Fundamental types in all shapes and sizes
Integers can be signed or unsigned, and can have 8, 16, 32, 64, or 128 bits. Floating point numbers can be binary 16-, 32-, 64-, 80-, or 128-bit; or decimal 32-, 64-, or 128-bit. Machine word sized integers also exist in signed and unsigned variants. And hardware sized floats as well.
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Bigints and multiple-precision floats
The last option on the zero-one-infinity rule.
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Unit type
Everything has a value, even if a meaningless one.
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Modules
A nice module system is nice.
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Purity
Maybe D-like, in that only observable purity is required.
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Number theory concepts
Rings, groups, etc, can be defined by types. This is the basis for things like operator +.
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Proper resource handling
As in C++ style scope based resource management.
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Octal or binary literals
Octal is only ever useful for
chmod. Binary is hardly useful for anything over 8 bits. Hexadecimal should cover everyone's needs. Write a syntactic extension if you desperately want binary or octal literals. -
Support for anything other than x86 and ARM
If it forces me to make the language any more complex than I want, I don't care about your platform.
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void
A function that returns nothing? Sorry, but no. Return unit, it's implicit.
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Global namespace
Namespace all the things