Module: RuVim::DisplayWidthExt

Defined in:

ext/ruvim/ruvim_ext.c

Class Method Summary

• .cell_width(*args) ⇒ Object

  ------------------------------------------------------------------.

• .display_width(*args) ⇒ Object

  ------------------------------------------------------------------.

• .expand_tabs(*args) ⇒ Object

  ------------------------------------------------------------------.

• .set_ambiguous_width(w) ⇒ Object

  ------------------------------------------------------------------.

Class Method Details

.cell_width(*args) ⇒ Object

---

# File 'ext/ruvim/ruvim_ext.c', line 105

static VALUE
rb_cell_width(int argc, VALUE *argv, VALUE self)
{
    VALUE ch, opts;
    rb_scan_args(argc, argv, "1:", &ch, &opts);

    if (NIL_P(ch) || (TYPE(ch) == T_STRING && RSTRING_LEN(ch) == 0))
        return INT2FIX(1);

    int col = 0, tabstop = 2;
    if (!NIL_P(opts)) {
        VALUE v;
        static ID id_col, id_tabstop;
        if (!id_col) {
            id_col = rb_intern("col");
            id_tabstop = rb_intern("tabstop");
        }
        v = rb_hash_lookup2(opts, ID2SYM(id_col), Qnil);
        if (!NIL_P(v)) col = NUM2INT(v);
        v = rb_hash_lookup2(opts, ID2SYM(id_tabstop), Qnil);
        if (!NIL_P(v)) tabstop = NUM2INT(v);
    }

    if (TYPE(ch) != T_STRING) return INT2FIX(1);

    const char *ptr = RSTRING_PTR(ch);
    long len = RSTRING_LEN(ch);

    if (len == 1 && ptr[0] == '\t') {
        int w = tabstop - (col % tabstop);
        if (w == 0) w = tabstop;
        return INT2FIX(w);
    }

    /* Fast path: single-byte ASCII */
    if (len == 1) return INT2FIX(1);

    /* Decode first codepoint */
    unsigned int code = rb_enc_codepoint_len(ptr, ptr + len, NULL,
                                              rb_utf8_encoding());
    return INT2FIX(codepoint_width(code));
}

.display_width(*args) ⇒ Object

---

# File 'ext/ruvim/ruvim_ext.c', line 152

static VALUE
rb_display_width(int argc, VALUE *argv, VALUE self)
{
    VALUE str, opts;
    rb_scan_args(argc, argv, "1:", &str, &opts);

    int tabstop = 2, start_col = 0;
    if (!NIL_P(opts)) {
        VALUE v;
        static ID id_tabstop, id_start_col;
        if (!id_tabstop) {
            id_tabstop = rb_intern("tabstop");
            id_start_col = rb_intern("start_col");
        }
        v = rb_hash_lookup2(opts, ID2SYM(id_tabstop), Qnil);
        if (!NIL_P(v)) tabstop = NUM2INT(v);
        v = rb_hash_lookup2(opts, ID2SYM(id_start_col), Qnil);
        if (!NIL_P(v)) start_col = NUM2INT(v);
    }

    if (NIL_P(str)) str = rb_str_new("", 0);
    if (TYPE(str) != T_STRING) str = rb_String(str);

    const char *ptr = RSTRING_PTR(str);
    const char *end = ptr + RSTRING_LEN(str);
    rb_encoding *enc = rb_utf8_encoding();
    int col = start_col;

    while (ptr < end) {
        unsigned int code;
        int clen = rb_enc_precise_mbclen(ptr, end, enc);

        if (!MBCLEN_CHARFOUND_P(clen)) {
            /* invalid byte — skip one byte, width 1 */
            ptr++;
            col++;
            continue;
        }
        clen = MBCLEN_CHARFOUND_LEN(clen);
        code = rb_enc_codepoint(ptr, end, enc);
        ptr += clen;

        if (code == '\t') {
            int w = tabstop - (col % tabstop);
            if (w == 0) w = tabstop;
            col += w;
        } else if (clen == 1) {
            col++;  /* ASCII */
        } else {
            col += codepoint_width(code);
        }
    }

    return INT2FIX(col - start_col);
}

.expand_tabs(*args) ⇒ Object

---

# File 'ext/ruvim/ruvim_ext.c', line 212

static VALUE
rb_expand_tabs(int argc, VALUE *argv, VALUE self)
{
    VALUE str, opts;
    rb_scan_args(argc, argv, "1:", &str, &opts);

    int tabstop = 2, start_col = 0;
    if (!NIL_P(opts)) {
        VALUE v;
        static ID id_tabstop, id_start_col;
        if (!id_tabstop) {
            id_tabstop = rb_intern("tabstop");
            id_start_col = rb_intern("start_col");
        }
        v = rb_hash_lookup2(opts, ID2SYM(id_tabstop), Qnil);
        if (!NIL_P(v)) tabstop = NUM2INT(v);
        v = rb_hash_lookup2(opts, ID2SYM(id_start_col), Qnil);
        if (!NIL_P(v)) start_col = NUM2INT(v);
    }

    if (NIL_P(str)) str = rb_str_new("", 0);
    if (TYPE(str) != T_STRING) str = rb_String(str);

    const char *ptr = RSTRING_PTR(str);
    const char *end = ptr + RSTRING_LEN(str);
    rb_encoding *enc = rb_utf8_encoding();
    int col = start_col;

    VALUE out = rb_str_buf_new(RSTRING_LEN(str) + 32);
    rb_enc_associate(out, enc);

    while (ptr < end) {
        if (*ptr == '\t') {
            int w = tabstop - (col % tabstop);
            if (w == 0) w = tabstop;
            for (int i = 0; i < w; i++)
                rb_str_cat(out, " ", 1);
            col += w;
            ptr++;
        } else {
            int clen = rb_enc_precise_mbclen(ptr, end, enc);
            if (!MBCLEN_CHARFOUND_P(clen)) {
                rb_str_cat(out, ptr, 1);
                ptr++;
                col++;
                continue;
            }
            clen = MBCLEN_CHARFOUND_LEN(clen);
            unsigned int code = rb_enc_codepoint(ptr, end, enc);
            rb_str_cat(out, ptr, clen);
            col += (clen == 1) ? 1 : codepoint_width(code);
            ptr += clen;
        }
    }

    return out;
}

.set_ambiguous_width(w) ⇒ Object

---

# File 'ext/ruvim/ruvim_ext.c', line 274

static VALUE
rb_set_ambiguous_width(VALUE self, VALUE w)
{
    ambiguous_width = NUM2INT(w);
    return w;
}