Creating and iterating through a hash table

[ander-theo]

I'm having trouble getting hash table iteration to work. Based on the documentation, here's what I am trying:

WRValue container;
wr_makeContainer( &container );

WRValue integer;
wr_makeInt( &integer, 99 );
wr_addValueToContainer( &container, "integer", &integer );

WRValue integer2;
wr_makeInt( &integer2, 100 );
wr_addValueToContainer( &container, "integer2", &integer2 );

for (WRIteratorEntry const& member : container)
{
      cout << member.value->asInt() << "\n";
}

  wr_destroyContainer(&container);

The issue is that the for loop is never entered, and it seems the iterator is always null. When debugging I am able to see that container has an xtype of WR_EX_HASH_TABLE and a size of 2. Am I going about this the right way? (I am using C++ 17 by the way)

For more context, I would ultimately like to create a hash table, add values, then pass it as an argument to a wrench function, then iterate through it in the C++ code to check for changes and update a corresponding C++ hash accordingly. Here's a full example:

#include <iostream>
#include <map>
#include <string.h>
#include "wrench.h"

using namespace std;

void print(WRContext* c, const WRValue* argv, const int argn, WRValue& retVal, void* usr)
{
    char buf[128];
    for (int i = 0; i < argn; ++i)
    {
        cout << (argv[i].asString(buf, 128));
        cout << "\n";
    }
}

int main() {
    WRState* wr_state = wr_newState(20);
    wr_registerFunction(wr_state, "print", print);

    std::map<string, int> values;
    values["temperature"] = 80;
    values["humidity"] = 11;

    string code = "function wrenchfunction(values){"
        "print(\"humidity:\");print( values[\"humidity\"] );"
        "print(\"temperature:\");print( values[\"temperature\"] );"
        "values[\"humidity\"] += 100;"
        "print(\"humidity:\");print( values[\"humidity\"] );"
        "print(\"temperature:\");print( values[\"temperature\"] );"
        "return values;}";

    //Transform Values
    WRValue wrench_values;
    wr_makeContainer(&wrench_values);

    for (const auto& [id, value] : values) {
        WRValue* wr_value = new WRValue();
        wr_makeInt(wr_value, value);
        wr_addValueToContainer(&wrench_values, id.c_str(), wr_value);
    }

    //Compile and Run
    unsigned char* outBytes;
    int outLen;
    
    const char* wrenchCode = code.c_str();
    
    wr_compile(wrenchCode, strlen(wrenchCode), &outBytes, &outLen);
    WRContext* context = wr_run(wr_state, outBytes, outLen);
    
    wr_callFunction(context, "wrenchfunction", &wrench_values, 1);
    
    free(outBytes);

    //Update Values and Free Memory
    for (WRIteratorEntry const& member : wrench_values)
    {
        char key[156];
        values[(member.key->asString(key, 156))] = member.value->asInt();
        delete member.value;
    }

    cout << "\nUpdated Values:\n";
    for (const auto& [key, value] : values) {
        cout << key << ": " << value << "\n";
    }

    wr_destroyContainer(&wrench_values);
}

Again, the problem here is that the for loop is never entered (and as such the C++ values map is not updated), however the wrench code does run correctly and interacts with the hash table as expected.

Here is the output:

humidity:
11
temperature:
80
humidity:
111
temperature:
80

Updated Values:
humidity: 11
temperature: 80

Any help is greatly appreciated!

[jingoro2112]

Okay I'll look into this as soon as I can, but I am off for the week.

…

On Tue, Jul 2, 2024 at 8:08 PM Ander ***@***.***> wrote: I'm having trouble getting hash table iteration to work. Based on the documentation, here's what I am trying: WRValue container; wr_makeContainer( &container ); WRValue integer; wr_makeInt( &integer, 99 ); wr_addValueToContainer( &container, "integer", &integer ); WRValue integer2; wr_makeInt( &integer2, 100 ); wr_addValueToContainer( &container, "integer2", &integer2 ); for (WRIteratorEntry const& member : container) { cout << member.value->asInt() << "\n"; } wr_destroyContainer(&container); The issue is that the for loop is never entered, and it seems the iterator is always null. When debugging I am able to see that container has an xtype of WR_EX_HASH_TABLE and a size of 2. Am I going about this the right way? (I am using C++ 17 by the way) For more context, I would ultimately like to create a hash table, add values, then pass it as an argument to a wrench function, then iterate through it in the C++ code to check for changes and update a corresponding C++ hash accordingly. Here's a full example: #include <iostream> #include <map> #include <string.h> #include "wrench.h" using namespace std; void print(WRContext* c, const WRValue* argv, const int argn, WRValue& retVal, void* usr) { char buf[128]; for (int i = 0; i < argn; ++i) { cout << (argv[i].asString(buf, 128)); cout << "\n"; } } int main() { WRState* wr_state = wr_newState(20); wr_registerFunction(wr_state, "print", print); std::map<string, int> values; values["temperature"] = 80; values["humidity"] = 11; string code = "function wrenchfunction(values){" "print(\"humidity:\");print( values[\"humidity\"] );" "print(\"temperature:\");print( values[\"temperature\"] );" "values[\"humidity\"] += 100;" "print(\"humidity:\");print( values[\"humidity\"] );" "print(\"temperature:\");print( values[\"temperature\"] );" "return values;}"; //Transform Values WRValue wrench_values; wr_makeContainer(&wrench_values); for (const auto& [id, value] : values) { WRValue* wr_value = new WRValue(); wr_makeInt(wr_value, value); wr_addValueToContainer(&wrench_values, id.c_str(), wr_value); } //Compile and Run unsigned char* outBytes; int outLen; const char* wrenchCode = code.c_str(); wr_compile(wrenchCode, strlen(wrenchCode), &outBytes, &outLen); WRContext* context = wr_run(wr_state, outBytes, outLen); wr_callFunction(context, "wrenchfunction", &wrench_values, 1); free(outBytes); //Update Values and Free Memory for (WRIteratorEntry const& member : wrench_values) { char key[156]; values[(member.key->asString(key, 156))] = member.value->asInt(); delete member.value; } cout << "\nUpdated Values:\n"; for (const auto& [key, value] : values) { cout << key << ": " << value << "\n"; } wr_destroyContainer(&wrench_values); } Again, the problem here is that the for loop is never entered (and as such the C++ values map is not updated), however the wrench code does run correctly and interacts with the hash table as expected. — Reply to this email directly, view it on GitHub <#42>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AALIKA6F2BZMALBQKJNAFYTZKM6HDAVCNFSM6AAAAABKIPWGUCVHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZWHA4TCNJRGE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[jingoro2112]

Okay preliminary check it seems I am generating the end/begin objects incorrectly for hash tables. This is only a c++ iterator problem because internally wrench doesn't use them. I'll figure out a good solution to this and should have a fix in a few days

This issue was removed? is it still relevant?

[jingoro2112]

This has been fixed in 6.0.4 I changed the way memory is allocated and also made sure the iterating will work.

[ander-theo]

Thank you!!