string.cpp

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#include "StdLib.hpp"
#include <string>
 
namespace Phasor
{
 
void StdLib::registerStringFunctions(VM *vm)
{
    vm->registerNativeFunction("find", StdLib::str_find);
    vm->registerNativeFunction("len", StdLib::str_len);
    vm->registerNativeFunction("char_at", StdLib::str_char_at);
    vm->registerNativeFunction("substr", StdLib::str_substr);
    vm->registerNativeFunction("concat", StdLib::str_concat);
    vm->registerNativeFunction("to_upper", StdLib::str_upper);
    vm->registerNativeFunction("to_lower", StdLib::str_lower);
    vm->registerNativeFunction("starts_with", StdLib::str_starts_with);
    vm->registerNativeFunction("ends_with", StdLib::str_ends_with);
 
    vm->registerNativeFunction("sb_new", StdLib::sb_new);
    vm->registerNativeFunction("sb_append", StdLib::sb_append);
    vm->registerNativeFunction("sb_to_string", StdLib::sb_to_string);
    vm->registerNativeFunction("sb_free", StdLib::sb_free);
    vm->registerNativeFunction("sb_clear", StdLib::sb_clear);
}
 
// StringBuilder Pool
static std::vector<std::string> sbPool;
static std::vector<size_t>      sbFreeIndices;
 
int64_t StdLib::str_find(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 2, "find", true);
    std::string s = args[0].asString();
    std::string sub = args[1].asString();
    size_t      pos;
    if (args.size() == 3)
    {
        int64_t start = args[2].asInt();
        pos = s.find(sub, start);
        if (pos != std::string::npos)
        {
            return static_cast<int64_t>(pos);
        }
        return -1;
    }
    else if (args.size() == 4)
    {
        int64_t start = args[2].asInt();
        int64_t end = args[3].asInt();
        pos = s.find(sub, start);
        if (pos != std::string::npos && pos < static_cast<size_t>(end))
        {
            return static_cast<int64_t>(pos);
        }
        return -1;
    }
    else
    {
        pos = s.find(sub);
    }
    return pos != std::string::npos ? static_cast<int64_t>(pos) : false;
}
 
int64_t StdLib::sb_new(const std::vector<Value> &args, VM *)
{
    StdLib::checkArgCount(args, 0, "sb_new");
    size_t idx;
    if (!sbFreeIndices.empty())
    {
        idx = sbFreeIndices.back();
        sbFreeIndices.pop_back();
        sbPool[idx] = "";
    }
    else
    {
        idx = sbPool.size();
        sbPool.push_back("");
    }
    return static_cast<int64_t>(idx);
}
 
Value StdLib::sb_append(const std::vector<Value> &args, VM *)
{
    StdLib::checkArgCount(args, 2, "sb_append");
    int64_t idx = args[0].asInt();
    if (idx < 0 || idx >= static_cast<int64_t>(sbPool.size()))
        throw std::runtime_error("Invalid StringBuilder handle");
 
    sbPool[idx] += args[1].toString();
    return args[0]; // Return handle for chaining
}
 
std::string StdLib::sb_to_string(const std::vector<Value> &args, VM *)
{
    StdLib::checkArgCount(args, 1, "sb_to_string");
    int64_t idx = args[0].asInt();
    if (idx < 0 || idx >= static_cast<int64_t>(sbPool.size()))
        throw std::runtime_error("Invalid StringBuilder handle");
 
    return sbPool[idx];
}
 
std::string StdLib::sb_free(const std::vector<Value> &args, VM *)
{
    StdLib::checkArgCount(args, 1, "sb_free");
    size_t      idx = args[0].asInt();
    std::string value = sbPool[idx];
    sbFreeIndices.push_back(idx);
    return value;
}
 
Value StdLib::sb_clear(const std::vector<Value> &args, VM *)
{
    StdLib::checkArgCount(args, 1, "sb_clear");
    size_t idx = args[0].asInt();
    if (idx >= sbPool.size())
        throw std::runtime_error("Invalid StringBuilder handle");
    sbPool[idx].clear();
    return args[0]; // Return handle for chaining
}
 
Value StdLib::str_char_at(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 2, "char_at");
    if (args[0].isString())
    {
        const std::string &s = args[0].asString();
        int64_t            idx = args[1].asInt();
        if (idx < 0 || idx >= static_cast<int64_t>(s.length()))
            return Value("");
        return Value(std::string(1, s[idx]));
    }
    throw std::runtime_error("char_at() expects a string");
}
 
Value StdLib::str_substr(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 2, "substr", true);
    if (args.size() < 2 || args.size() > 3)
    {
        throw std::runtime_error("substr() expects 2 or 3 arguments");
    }
    std::string s = args[0].asString();
    int64_t     start = args[1].asInt();
    int64_t     len = (int64_t)args.size() == 3 ? args[2].asInt() : (int64_t)s.length() - start;
 
    if (start < 0 || start >= static_cast<int64_t>(s.length()))
    {
        return Value("");
    }
 
    return Value(s.substr(start, len));
}
 
std::string StdLib::str_concat(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 2, "concat");
    std::string result = "";
    for (const auto &arg : args)
    {
        result += arg.toString();
    }
    return result;
}
 
int64_t StdLib::str_len(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 1, "len");
    std::string s = args[0].toString();
    return static_cast<int64_t>(s.length());
}
 
std::string StdLib::str_upper(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 1, "to_upper");
    std::string s = args[0].asString();
    std::transform(s.begin(), s.end(), s.begin(), ::toupper);
    return s;
}
 
std::string StdLib::str_lower(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 1, "to_lower");
    std::string s = args[0].asString();
    std::transform(s.begin(), s.end(), s.begin(), ::tolower);
    return s;
}
 
Value StdLib::str_starts_with(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 2, "starts_with");
    std::string s = args[0].asString();
    std::string prefix = args[1].asString();
    if (s.length() >= prefix.length())
    {
        return Value(s.compare(0, prefix.length(), prefix) == 0);
    }
    return Value(false);
}
 
Value StdLib::str_ends_with(const std::vector<Value> &args, VM *)
{
    checkArgCount(args, 2, "ends_with");
    std::string s = args[0].asString();
    std::string suffix = args[1].asString();
    if (s.length() >= suffix.length())
    {
        return Value(s.compare(s.length() - suffix.length(), suffix.length(), suffix) == 0);
    }
    return Value(false);
}
} // namespace Phasor