daScript/examples/tutorial/tutorial06.cpp at master · fiveakatto/daScript · GitHub

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#include "daScript/daScript.h"

using namespace das;

#define TUTORIAL_NAME "/examples/tutorial/tutorial01.das"

typedef das_map<string, float> ExprVars; // variable lookup

class ExprCalc {

public:

ExprCalc ( const string & expr, const ExprVars & vars );

float compute(ExprVars & vars);

protected:

ContextPtr ctx; // context

SimFunction * fni = nullptr; // 'test' function

string text; // program text (for reference purposes)

das_map<string,float *> variables; // pointers to variables in context global data

};

float ExprCalc::compute(ExprVars & vars) {

if ( fni==nullptr ) { // if no function - no result

return 0.0f;

}

for ( auto & va : vars ) { // set variables

auto it = variables.find(va.first);

if ( it != variables.end() ) {

*(it->second) = va.second;

}

auto res = ctx->evalWithCatch(fni, nullptr); // eval the expression

if ( auto ex = ctx->getException() ) { // if exception - report it

TextPrinter tout;

tout << "with exception " << ex << "\n";

return 0.0f;

}

return cast<float>::to(res); // cast result to float

}

ExprCalc::ExprCalc ( const string & expr, const ExprVars & vars ) {

// build expression program

TextWriter ss;

ss << "require math\n";

for ( auto & va : vars ) {

ss << "var " << va.first << " = 0.0f\n"; // make each variable float, set to 0.0f by default

}

ss << "[export]\n"

<< "def test\n"

<< "\treturn " << expr << "\n"

<< "\n\n";

text = ss.str();

// make file access, introduce string as if it was a file

TextPrinter tout;

auto fAccess = make_smart<FsFileAccess>();

auto fileInfo = make_unique<TextFileInfo>(text.c_str(), uint32_t(text.length()), false);

fAccess->setFileInfo("dummy.das", das::move(fileInfo));

// compile script

ModuleGroup dummyLibGroup;

auto program = compileDaScript("dummy.das", fAccess, tout, dummyLibGroup);

if ( program->failed() ) {

// if compilation failed, report errors

tout << "failed to compile\n";

for ( auto & err : program->errors ) {

tout << reportError(err.at, err.what, err.extra, err.fixme, err.cerr );

}

return;

}

// create context

ctx = make_shared<Context>(program->getContextStackSize());

if ( !program->simulate(*ctx, tout) ) {

// if interpretation failed, report errors

tout << "failed to simulate\n";

for ( auto & err : program->errors ) {

tout << reportError(err.at, err.what, err.extra, err.fixme, err.cerr );

}

return;

}

// call context function

fni = ctx->findFunction("test");

// variables

for ( auto & va : vars ) {

auto idx = ctx->findVariable(va.first.c_str()); // find index of the variable

assert(idx != -1);

variables[va.first] = (float *) ctx->getVariable(idx); // get its pointer in context

}

int main( int, char * [] ) {

// request all da-script built in modules

NEED_ALL_DEFAULT_MODULES;

// Initialize modules

Module::Initialize();

// make calculator 'program'

ExprVars variables;

variables["a"] = 1.0f;

variables["b"] = 2.0f;

variables["c"] = 3.0f;

ExprCalc calc("a*b+c", variables);

// verify initial values

auto res = calc.compute(variables);

assert(res==5.0f);

// verify for the range of values

for ( float a=1.0f; a<4.0f; a++ ) {

variables["a"] = a;

for ( float b=1.0f; b<5.0f; b++ ) {

variables["b"] = b;

for ( float c=1.0f; c<6.0f; c++ ) {

variables["c"] = c;

float rref = a * b + c;

float reval = calc.compute(variables);

assert(rref==reval);

}

// shut-down daScript, free all memory

Module::Shutdown();

return 0;

}

daScript/examples/tutorial/tutorial06.cpp at master · fiveakatto/daScript · GitHub

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