USER

convert the following vim scripting function to Qt c++:

" render a suggestion at the current cursor location
function! s:fim_render(pos_x, pos_y, data)
    " do not show if there is a completion in progress
    if pumvisible()
        return
    endif
    let l:raw = a:data
    let l:can_accept = v:true
    let l:has_info   = v:false
    let l:n_prompt    = 0
    let l:t_prompt_ms = 1.0
    let l:s_prompt    = 0
    let l:n_predict    = 0
    let l:t_predict_ms = 1.0
    let l:s_predict    = 0
    let l:content = []
    " get the generated suggestion
    if l:can_accept
        let l:response = json_decode(l:raw)
        for l:part in split(get(l:response, 'content', ''), "\n", 1)
            call add(l:content, l:part)
        endfor
        " remove trailing new lines
        while len(l:content) > 0 && l:content[-1] == ""
            call remove(l:content, -1)
        endwhile
        let l:n_cached  = get(l:response, 'tokens_cached', 0)
        let l:truncated = get(l:response, 'timings/truncated', v:false)
        " if response.timings is available
        if has_key(l:response, 'timings/prompt_n') && has_key(l:response, 'timings/prompt_ms') && has_key(l:response, 'timings/prompt_per_second')
            \ && has_key(l:response, 'timings/predicted_n') && has_key(l:response, 'timings/predicted_ms') && has_key(l:response, 'timings/predicted_per_second')
            let l:n_prompt    = get(l:response, 'timings/prompt_n', 0)
            let l:t_prompt_ms = get(l:response, 'timings/prompt_ms', 1)
            let l:s_prompt    = get(l:response, 'timings/prompt_per_second', 0)
            let l:n_predict    = get(l:response, 'timings/predicted_n', 0)
            let l:t_predict_ms = get(l:response, 'timings/predicted_ms', 1)
            let l:s_predict    = get(l:response, 'timings/predicted_per_second', 0)
        endif
        let l:has_info = v:true
    endif
    if len(l:content) == 0
        call add(l:content, "")
        let l:can_accept = v:false
    endif
    let l:pos_x = a:pos_x
    let l:pos_y = a:pos_y
    let l:line_cur = getline(l:pos_y)
    " if the current line is full of whitespaces, trim as much whitespaces from the suggestion
    if match(l:line_cur, '^\s*$') >= 0
        let l:lead = min([strlen(matchstr(l:content[0], '^\s*')), strlen(l:line_cur)])
        let l:line_cur   = strpart(l:content[0], 0, l:lead)
        let l:content[0] = strpart(l:content[0],    l:lead)
    endif
    let l:line_cur_prefix = strpart(l:line_cur, 0, l:pos_x)
    let l:line_cur_suffix = strpart(l:line_cur, l:pos_x)
    " NOTE: the following is logic for discarding predictions that repeat existing text
    "       the code is quite ugly and there is very likely a simpler and more canonical way to implement this
    "
    "       still, I wonder if there is some better way that avoids having to do these special hacks?
    "       on one hand, the LLM 'sees' the contents of the file before we start editing, so it is normal that it would
    "       start generating whatever we have given it via the extra context. but on the other hand, it's not very
    "       helpful to re-generate the same code that is already there
    " truncate the suggestion if the first line is empty
    if len(l:content) == 1 && l:content[0] == ""
        let l:content = [""]
    endif
    " ... and the next lines are repeated
    if len(l:content) > 1 && l:content[0] == "" && l:content[1:] == getline(l:pos_y + 1, l:pos_y + len(l:content) - 1)
        let l:content = [""]
    endif
    " truncate the suggestion if it repeats the suffix
    if len(l:content) == 1 && l:content[0] == l:line_cur_suffix
        let l:content = [""]
    endif
    " find the first non-empty line (strip whitespace)
    let l:cmp_y = l:pos_y + 1
    while l:cmp_y < line('$') && getline(l:cmp_y) =~? '^\s*$'
        let l:cmp_y += 1
    endwhile
    if (l:line_cur_prefix . l:content[0]) == getline(l:cmp_y)
        " truncate the suggestion if it repeats the next line
        if len(l:content) == 1
            let l:content = [""]
        endif
        " ... or if the second line of the suggestion is the prefix of line l:cmp_y + 1
        if len(l:content) == 2 && l:content[-1] == getline(l:cmp_y + 1)[:len(l:content[-1]) - 1]
            let l:content = [""]
        endif
        " ... or if the middle chunk of lines of the suggestion is the same as [l:cmp_y + 1, l:cmp_y + len(l:content) - 1)
        if len(l:content) > 2 && join(l:content[1:-1], "\n") == join(getline(l:cmp_y + 1, l:cmp_y + len(l:content) - 1), "\n")
            let l:content = [""]
        endif
    endif

    let l:content[-1] .= l:line_cur_suffix
    " if only whitespaces - do not accept
    if join(l:content, "\n") =~? '^\s*$'
        let l:can_accept = v:false
    endif
    " display virtual text with the suggestion
    let l:bufnr = bufnr('%')
    let l:info = ''

    let s:hint_shown = v:true
    let s:fim_data['pos_x']  = l:pos_x
    let s:fim_data['pos_y']  = l:pos_y
    let s:fim_data['line_cur'] = l:line_cur
    let s:fim_data['can_accept'] = l:can_accept
    let s:fim_data['content']    = l:content
endfunction

Qwen3 Coder 30b

Here’s the C++ equivalent of your Vim script function using Qt:

#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonArray>
#include <QStringList>
#include <QRegularExpression>
#include <QTextBlock>
#include <QDebug>

class FimRenderer {
private:
    bool m_hintShown = false;
    struct FimData {
        int pos_x = 0;
        int pos_y = 0;
        QString line_cur;
        bool can_accept = false;
        QStringList content;
    } m_fim_data;

public:
    void fim_render(int pos_x, int pos_y, const QString& data) {
        // do not show if there is a completion in progress
        // Assuming we have some way to check if completion is visible
        if (is_completion_visible()) {
            return;
        }

        QString raw = data;
        bool can_accept = true;
        bool has_info = false;
        int n_prompt = 0;
        double t_prompt_ms = 1.0;
        double s_prompt = 0;
        int n_predict = 0;
        double t_predict_ms = 1.0;
        double s_predict = 0;
        QStringList content;

        // get the generated suggestion
        if (can_accept) {
            QJsonParseError error;
            QJsonDocument doc = QJsonDocument::fromJson(raw.toUtf8(), &error);
            
            if (error.error != QJsonParseError::NoError) {
                can_accept = false;
                content << "";
                return;
            }

            QJsonObject response = doc.object();
            
            // Extract content
            QString content_str = response.value("content").toString();
            content = content_str.split('\n', Qt::SkipEmptyParts);
            
            // Remove trailing new lines
            while (!content.isEmpty() && content.back().isEmpty()) {
                content.removeLast();
            }
            
            int n_cached = response.value("tokens_cached").toInt(0);
            bool truncated = response.value("timings/truncated").toBool(false);
            
            // Check if timings data is available
            if (response.contains("timings/prompt_n") && 
                response.contains("timings/prompt_ms") && 
                response.contains("timings/prompt_per_second") &&
                response.contains("timings/predicted_n") && 
                response.contains("timings/predicted_ms") && 
                response.contains("timings/predicted_per_second")) {
                
                n_prompt = response.value("timings/prompt_n").toInt(0);
                t_prompt_ms = response.value("timings/prompt_ms").toDouble(1.0);
                s_prompt = response.value("timings/prompt_per_second").toDouble(0);
                n_predict = response.value("timings/predicted_n").toInt(0);
                t_predict_ms = response.value("timings/predicted_ms").toDouble(1.0);
                s_predict = response.value("timings/predicted_per_second").toDouble(0);
            }
            
            has_info = true;
        }

        if (content.isEmpty()) {
            content << "";
            can_accept = false;
        }

        int line_cur_pos_y = pos_y; // This would come from actual editor context
        QString line_cur = get_line_content(line_cur_pos_y); // Implement based on your editor
        
        // if the current line is full of whitespaces, trim as much whitespaces from the suggestion
        QRegularExpression whitespace_pattern("^\\s*$");
        if (whitespace_pattern.match(line_cur).hasMatch()) {
            int lead = qMin(line_cur.length(), content.isEmpty() ? 0 : content.first().length());
            QString line_cur_trimmed = line_cur.left(lead);
            if (!content.isEmpty()) {
                content[0] = content[0].mid(lead);
            }
        }

        QString line_cur_prefix = line_cur.left(pos_x);
        QString line_cur_suffix = line_cur.mid(pos_x);

        // Logic for discarding predictions that repeat existing text
        // truncate the suggestion if the first line is empty
        if (content.size() == 1 && content[0].isEmpty()) {
            content = QStringList{""};
        }
        
        // ... and the next lines are repeated
        if (content.size() > 1 && content[0].isEmpty() && 
            content.mid(1) == get_lines_content(line_cur_pos_y + 1, line_cur_pos_y + content.size() - 1)) {
            content = QStringList{""};
        }
        
        // truncate the suggestion if it repeats the suffix
        if (content.size() == 1 && content[0] == line_cur_suffix) {
            content = QStringList{""};
        }
        
        // Find the first non-empty line
        int cmp_y = line_cur_pos_y + 1;
        while (cmp_y < get_total_lines() && 
               get_line_content(cmp_y).trimmed().isEmpty()) {
            cmp_y++;
        }
        
        if (!content.isEmpty() && 
            (line_cur_prefix + content[0]) == get_line_content(cmp_y)) {
            
            // truncate the suggestion if it repeats the next line
            if (content.size() == 1) {
                content = QStringList{""};
            }
            
            // ... or if the second line of the suggestion is the prefix of line cmp_y + 1
            if (content.size() == 2 && 
                content.back() == get_line_content(cmp_y + 1).left(content.back().length())) {
                content = QStringList{""};
            }
            
            // ... or if the middle chunk of lines of the suggestion is the same as [cmp_y + 1, cmp_y + content.size() - 1)
            if (content.size() > 2 && 
                content.mid(1).join("\n") == get_lines_content(cmp_y + 1, cmp_y + content.size() - 1).join("\n")) {
                content = QStringList{""};
            }
        }

        // Add suffix to last line
        if (!content.isEmpty()) {
            content.back() += line_cur_suffix;
        }
        
        // if only whitespaces - do not accept
        QString combined_content = content.join("\n");
        QRegularExpression whitespace_only_pattern("^\\s*$");
        if (whitespace_only_pattern.match(combined_content).hasMatch()) {
            can_accept = false;
        }

        // display virtual text with the suggestion
        m_fim_data.pos_x = pos_x;
        m_fim_data.pos_y = pos_y;
        m_fim_data.line_cur = line_cur;
        m_fim_data.can_accept = can_accept;
        m_fim_data.content = content;
        
        m_hintShown = true;
    }

private:
    bool is_completion_visible() {
        // Implement based on your Qt editor implementation
        return false; // Placeholder
    }
    
    QString get_line_content(int line_number) {
        // Implement based on your Qt editor implementation
        return ""; // Placeholder
    }
    
    QStringList get_lines_content(int start_line, int end_line) {
        // Implement based on your Qt editor implementation
        return QStringList(); // Placeholder
    }
    
    int get_total_lines() {
        // Implement based on your Qt editor implementation
        return 0; // Placeholder
    }
};

Key differences from the original Vim script:

  1. Data Structures: Uses QStringList instead of Vim lists, QJsonObject for JSON handling instead of json_decode
  2. Error Handling: Added proper error checking for JSON parsing
  3. String Operations: Qt’s string methods are used instead of Vim’s string functions
  4. Regular Expressions: Used QRegularExpression instead of Vim’s regex matching
  5. Memory Management: C++ handles memory automatically, no need for explicit cleanup
  6. Editor Integration: The actual editor integration methods (get_line_content, etc.) need to be implemented based on your specific Qt-based editor setup

Important Notes:

  1. You’ll need to implement the editor-specific helper methods like get_line_content(), get_lines_content(), and get_total_lines() based on your Qt editor implementation
  2. The is_completion_visible() method needs to be implemented to detect if there’s an active completion popup
  3. This assumes you’re working within a Qt-based editor environment that provides access to document content and cursor positions
  4. The JSON parsing uses Qt’s QJsonDocument which is more robust than Vim’s JSON handling
  5. Error handling for missing keys in JSON objects is included