Programming Language
BlitzMax Forums/BlitzMax Programming/Programming Language
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| Anyone made one in Blitzmax? What did you use for the parser, handwritten or generated? |
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| If you see a 'programming language' as: 'giving instructions to a computer' or 'giving instructions to its host program' then I made a simple script parser, years ago. I think it's in the archives somewhere. It's basically command, value, command, value, command, value etc. Very simple, but adequate for what I wanted (a texture generator). |
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| http://www.blitzbasic.com/Community/posts.php?topic=77298 MicroC. This is written in pure bmax. |
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| I was more talking about something that can evaluate expressions, like: a*2+10 |
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| @Azathoth I believe Brucey has a module that parses mathematical expressions such as the example you gave -Mic |
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| It's like deja vu all over again :-) |
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| I did this small script language on BlitzMax. It's not been very well tested, but it seems to work... http://www.blitzbasic.com/codearcs/codearcs.php?code=2103 |
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| There's no shortage of these written in Blitz3D. If you're feeling adventurous you could always rewrite this or this or even this in BlitzMax? |
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| muParser isn't really what I'm looking for, and I've written something similar in C++ (although no where near as many features as muParser). There doesn't appear to be anyway to get the bytecode or redefine operators. MicroC and ziggy's look interesting. The only thing like a parser generator seems to be this by grable, but doesn't appear to have been updated since 2 years ago. |
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| I've got an unconventional parser/interpreter system that I've been using for a lot of my things lately. What kind of thing is it you're looking for? Making something which can parse mathematical expressions is pretty easy, and I think mark's posted a bmax one somewhere previously. |
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| Would the JSON readers by Warpy and/or by grable do this? |
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| I haven't done expressions yet but I am working on a scriptable engine. Similar to CS_TBL I basically have a `command` followed by a number of `paremeters`, in an array. Very simple, similar to assembly language where you basically just issue one simple instruction with a few (or no) parameters to move data around, do math on it, etc. Very easy to implement and pretty fast to `run` it. |
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| Really wanted to see how people implemented things like structures, functions and compile time expressions; for example MicroC will evaluate the whole expression: a+2+1 at run time when it could evaluate '2+1' at compile time. Also checking if there was any other parser generators. |
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| What I'm thinking to do, to handle expressions, is to require the strict use of pairs of brackets to isolate things, and to otherwise evaluate from left to right. ie a+(4/2) is different to a+4/2. You can recursively count the brackets until you get to a right bracket and then do whatever is between them, and work your way back up. |
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| a+4/2 and a+(4/2) should be the same, / has a higher operator precedence than +. My parsers I've written had no problem there, it was expressions that should be evaluated at compile time rather than run time I've had trouble with. |
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| Looks like theres some people working on scriptable engines atm; Skully, IH, Leadwerks, me included. I'm just having something with full-blown function definition, classes, constants, variables, pragmas, expressions - plain bmax -but unfortnately its bound to a whitebox framework so it wont realy serve you i presume. in addition its type-free (string based local vars) so it will be too slow in most peoples eyes. |
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| Is it interpreted or compiles to bytecode? |
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| Its compiled into a hierarchy of expression objects, where an expression object may have a function or a modificator or a set operator plus an operator and subexpressions.Those get recursively evaluated on running an expression. sample syntax (obviously a little messy atm):
define__
MyConstant:=2.7174;
include__
MyConstantsAndFunctionsCollection;
MyFunction( MyParameter )
[
return MyReturnVar;
local MyVar;
\\{this is a comment on the senseless stuff done below}
{(
if( (\%MyParameter=MyConstant)
then((\%MyVar):=(\%MyConstant^2))
else((\%MyVar):=(mystring))
)
(\%MyReturnVar:=\%parent.MyFunction.MyVar)
)}
\parent.MyFunction{ (myConstant) } \\{lets have the function call itself to crash the application!}
]
I think, its pretty much the easiest way to let a scripting language behave in a way one may call 'professional'. The actual downside of that object-based compilation might be the higher mem-consumption. The language itself is actually just the 'visible part' of a whole nodegraph based virtual machine. if i get work done today, i showcase that tomorrow. Its completely free, so the code for the compiler will be included and you can check out whether it fits your purposes. |
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