Tag: regscript

Entries for tag "regscript", ordered from most recent. Entry count: 2.

Pages: 1

# RegScript - Bidirectional Type Inference

Sun
03
Jan 2010

Coding my RegScript programming language is no longer easy as code grows bigger, but it's still much fun. In the last days I've added support for numeric types of different size. Here is the full list: float, double, uint8, uint16, uint32 (uint), uint64, int8, int16, int32 (int), int64.

I try to keep the syntax as close to C/C++ as possible, but at the same time I introduce some interesting details like:

• Conversion between types, e.g. char to string (of length 1), any type to string (makes string representation of a value) or string to any type (tries to parse the string). Implicit conversions of this kind generate compiler warning though.
• Indexing with multiple indices: object[x,y,z]
• Arbitrary expressions as default function parameters: void Func(float x = sin(globalVar)) { ... }
• Multiple values in switch case label: switch (val) { case 1, 2, 3: ...
• Arbitrary expressions in switch case label: switch (val) { case someVar+1: ...
• Possibility to define variables in switch case labels.

I've also implemented function overloading and many compiler errors and warnings similar to these from C++ compiler. But most interesting feature so far is what I call "Bidirectional Type Inference" :) I first introduced auto keyword to allow skipping type name and next I've made literal constants like 123 typeless so their type is deduced from the context (because I hate typing this f, u or ll postfixes everywhere in C++ code). For example:

// Left to right - these numbers are int16
int16 myShort = -32000 + 10;
// Right to left - newVar is int16
auto newVar = myShort;

Comments | #c++ #compilers #regscript Share

# RegScript - my Scripting Language

Wed
30
Dec 2009

RegScript is my scripting language I've started coding yesterday. I'm not a guru in formal languages theory, but I'm quite fascinated with programming languages, parsers and interpreters. I don't know why but I felt I'd love to write my own programming language so I just started coding it, even if it doesn't make any sense. Maybe that's just because it's like being the creator of something that we, as developers, are usually only users. The language syntax is similar to C++. Here are features I've coded untill now:

• Variable types: bool, int, float, char, string, auto (automatic type inference)
• Values like: -10, 0xFFFF, 0b1010, 1e-6f, false, true, 'A', "foo"
• Operators: + - * / % < ?: ! && || ~ & | ^ << >> = += -= *= /= %= &= |= ^= <<= >>= ++ -- == != < > <= >= ( ) sizeof ,
• Instructions: if-else, while, do-while, for
• Intrinsic functions: sin, print, intrinsic constants: PI.

The implementation is not optimal yet as I don't generate any bytecode. I just execute statements and evaluate expressions from a tree made of polymorphic nodes dynamically allocated by parser. Sample program:

print("Hello World!\n");
for (auto i = 0; i < 10; i++)
  print("i = " + i + '\n');

Comments | #scripts #compilers #regscript Share

Pages: 1