access to generator names

mezzarobba · mezzarobba · commit e6320e7a4406 · 2025-05-09T14:35:40.000+02:00
diff --git a/doc/source/gr.rst b/doc/source/gr.rst
@@ -270,6 +270,15 @@ Context operations
     The name is used when printing and may be used to choose
     coercions.
 
+.. function:: slong gr_ctx_ngens(gr_ctx_t ctx)
+
+    Returns the number of generators.
+
+.. function:: char const * const * gr_ctx_gen_names_srcptr(gr_ctx_t ctx)
+
+    Returns an array containing the names of the generators, or `NULL` if there
+    are no generators.
+
 Element operations
 --------------------------------------------------------------------------------
 
diff --git a/src/gr.h b/src/gr.h
@@ -110,6 +110,8 @@ typedef enum
     GR_METHOD_CTX_SET_IS_FIELD,
     GR_METHOD_CTX_SET_GEN_NAME,
     GR_METHOD_CTX_SET_GEN_NAMES,
+    GR_METHOD_CTX_NGENS,
+    GR_METHOD_CTX_GEN_NAMES_SRCPTR,
 
     GR_METHOD_INIT,
     GR_METHOD_CLEAR,
@@ -719,6 +721,8 @@ typedef void ((*gr_method_init_clear_op)(gr_ptr, gr_ctx_ptr));
 typedef void ((*gr_method_swap_op)(gr_ptr, gr_ptr, gr_ctx_ptr));
 typedef int ((*gr_method_ctx)(gr_ctx_ptr));
 typedef truth_t ((*gr_method_ctx_predicate)(gr_ctx_ptr));
+typedef slong ((*gr_method_ctx_size)(gr_ctx_ptr));
+typedef char const * const * ((*gr_method_ctx_gen_names_srcptr)(gr_ctx_ptr));
 typedef int ((*gr_method_ctx_set_si)(gr_ctx_ptr, slong));
 typedef int ((*gr_method_ctx_get_si)(slong *, gr_ctx_ptr));
 typedef int ((*gr_method_ctx_set_truth)(gr_ctx_ptr, truth_t));
@@ -816,6 +820,8 @@ typedef int ((*gr_method_set_fexpr_op)(gr_ptr, fexpr_vec_t, gr_vec_t, const fexp
 #define GR_CTX_OP(ctx, NAME) (((gr_method_ctx *) ctx->methods)[GR_METHOD_ ## NAME])
 #define GR_CTX_STREAM(ctx, NAME) (((gr_method_ctx_stream *) ctx->methods)[GR_METHOD_ ## NAME])
 #define GR_CTX_PREDICATE(ctx, NAME) (((gr_method_ctx_predicate *) ctx->methods)[GR_METHOD_ ## NAME])
+#define GR_CTX_SIZE(ctx, NAME) (((gr_method_ctx_size *) ctx->methods)[GR_METHOD_ ## NAME])
+#define GR_CTX_GEN_NAMES_SRCPTR(ctx, NAME) (((gr_method_ctx_gen_names_srcptr *) ctx->methods)[GR_METHOD_ ## NAME])
 #define GR_CTX_SET_SI(ctx, NAME) (((gr_method_ctx_set_si *) ctx->methods)[GR_METHOD_ ## NAME])
 #define GR_CTX_GET_SI(ctx, NAME) (((gr_method_ctx_get_si *) ctx->methods)[GR_METHOD_ ## NAME])
 #define GR_CTX_SET_TRUTH(ctx, NAME) (((gr_method_ctx_set_truth *) ctx->methods)[GR_METHOD_ ## NAME])
@@ -940,6 +946,8 @@ GR_INLINE WARN_UNUSED_RESULT int gr_ctx_get_real_prec(slong * prec, gr_ctx_t ctx
 GR_INLINE WARN_UNUSED_RESULT int gr_ctx_set_is_field(gr_ctx_t ctx, truth_t is_field) { return GR_CTX_SET_TRUTH(ctx, CTX_SET_IS_FIELD)(ctx, is_field); }
 GR_INLINE WARN_UNUSED_RESULT int gr_ctx_set_gen_name(gr_ctx_t ctx, const char * s) { return GR_CTX_SET_STR(ctx, CTX_SET_GEN_NAME)(ctx, s); }
 GR_INLINE WARN_UNUSED_RESULT int gr_ctx_set_gen_names(gr_ctx_t ctx, const char ** s) { return GR_CTX_SET_STRS(ctx, CTX_SET_GEN_NAMES)(ctx, s); }
+GR_INLINE slong gr_ctx_ngens(gr_ctx_t ctx) { return GR_CTX_SIZE(ctx, CTX_NGENS)(ctx); }
+GR_INLINE char const * const * gr_ctx_gen_names_srcptr(gr_ctx_t ctx) { return GR_CTX_GEN_NAMES_SRCPTR(ctx, CTX_GEN_NAMES_SRCPTR)(ctx); }
 
 GR_INLINE slong _gr_ctx_get_real_prec(gr_ctx_t ctx)
 {
diff --git a/src/gr/fmpq_poly.c b/src/gr/fmpq_poly.c
@@ -50,6 +50,11 @@ int _gr_fmpq_poly_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_fmpq_poly_ctx_set_gen_name(ctx, s[0]);
 }
 
+const char * const *
+_gr_fmpq_poly_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (const char * const *) &FMPQ_POLY_CTX_VAR(ctx);
+}
 
 int
 _gr_fmpq_poly_ctx_write(gr_stream_t out, gr_ctx_t ctx)
@@ -735,6 +740,8 @@ gr_method_tab_input _fmpq_poly_methods_input[] =
 
     {GR_METHOD_CTX_SET_GEN_NAME,  (gr_funcptr) _gr_fmpq_poly_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES, (gr_funcptr) _gr_fmpq_poly_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fmpq_poly_ctx_gen_names_srcptr},
     {GR_METHOD_INIT,            (gr_funcptr) _gr_fmpq_poly_init},
     {GR_METHOD_CLEAR,           (gr_funcptr) _gr_fmpq_poly_clear},
     {GR_METHOD_SWAP,            (gr_funcptr) _gr_fmpq_poly_swap},
diff --git a/src/gr/fmpz_mpoly.c b/src/gr/fmpz_mpoly.c
@@ -85,6 +85,18 @@ _gr_fmpz_mpoly_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return GR_SUCCESS;
 }
 
+slong
+_gr_fmpz_mpoly_ctx_ngens(gr_ctx_t ctx)
+{
+    return MPOLYNOMIAL_MCTX(ctx)->minfo->nvars;
+}
+
+char const * const
+_gr_fmpz_mpoly_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const) MPOLYNOMIAL_CTX(ctx)->vars;
+}
+
 void
 _gr_fmpz_mpoly_init(fmpz_mpoly_t res, gr_ctx_t ctx)
 {
@@ -569,6 +581,8 @@ gr_method_tab_input _gr_fmpz_mpoly_methods_input[] =
     {GR_METHOD_CTX_IS_FINITE_CHARACTERISTIC,    (gr_funcptr) gr_generic_ctx_predicate_false},
     {GR_METHOD_CTX_IS_THREADSAFE,               (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_SET_GEN_NAMES,               (gr_funcptr) _gr_fmpz_mpoly_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,   (gr_funcptr) _gr_fmpz_mpoly_ctx_ngens},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fmpz_mpoly_ctx_gen_names_srcptr},
     {GR_METHOD_INIT,        (gr_funcptr) _gr_fmpz_mpoly_init},
     {GR_METHOD_CLEAR,       (gr_funcptr) _gr_fmpz_mpoly_clear},
     {GR_METHOD_SWAP,        (gr_funcptr) _gr_fmpz_mpoly_swap},
diff --git a/src/gr/fmpz_mpoly_q.c b/src/gr/fmpz_mpoly_q.c
@@ -43,9 +43,13 @@ int _gr_fmpz_mpoly_q_ctx_write(gr_stream_t out, gr_ctx_t ctx)
 /* Some methods are identical to their fmpz_mpoly counterparts */
 void _gr_fmpz_mpoly_ctx_clear(gr_ctx_t ctx);
 int _gr_fmpz_mpoly_ctx_set_gen_names(gr_ctx_t ctx, const char ** s);
+slong _gr_fmpz_mpoly_ctx_ngens(gr_ctx_t ctx);
+char const * const _gr_fmpz_mpoly_ctx_gen_names_srcptr(gr_ctx_t ctx);
 
 #define _gr_fmpz_mpoly_q_ctx_clear _gr_fmpz_mpoly_ctx_clear
 #define _gr_fmpz_mpoly_q_ctx_set_gen_names _gr_fmpz_mpoly_ctx_set_gen_names
+#define _gr_fmpz_mpoly_q_ctx_ngens _gr_fmpz_mpoly_ctx_ngens
+#define _gr_fmpz_mpoly_q_ctx_gen_names_srcptr _gr_fmpz_mpoly_ctx_gen_names_srcptr
 
 void
 _gr_fmpz_mpoly_q_init(fmpz_mpoly_q_t res, gr_ctx_t ctx)
@@ -532,6 +536,8 @@ gr_method_tab_input _gr_fmpz_mpoly_q_methods_input[] =
     {GR_METHOD_CTX_IS_FINITE_CHARACTERISTIC,    (gr_funcptr) gr_generic_ctx_predicate_false},
     {GR_METHOD_CTX_IS_THREADSAFE,               (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_SET_GEN_NAMES,               (gr_funcptr) _gr_fmpz_mpoly_q_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,   (gr_funcptr) _gr_fmpz_mpoly_q_ctx_ngens},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fmpz_mpoly_q_ctx_gen_names_srcptr},
     {GR_METHOD_INIT,        (gr_funcptr) _gr_fmpz_mpoly_q_init},
     {GR_METHOD_CLEAR,       (gr_funcptr) _gr_fmpz_mpoly_q_clear},
     {GR_METHOD_SWAP,        (gr_funcptr) _gr_fmpz_mpoly_q_swap},
diff --git a/src/gr/fmpz_poly.c b/src/gr/fmpz_poly.c
@@ -53,6 +53,12 @@ int _gr_fmpz_poly_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_fmpz_poly_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_fmpz_poly_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &FMPZ_POLY_CTX_VAR(ctx);
+}
+
 int
 _gr_fmpz_poly_ctx_write(gr_stream_t out, gr_ctx_t ctx)
 {
@@ -828,6 +834,8 @@ gr_method_tab_input _fmpz_poly_methods_input[] =
 
     {GR_METHOD_CTX_SET_GEN_NAME,  (gr_funcptr) _gr_fmpz_poly_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES, (gr_funcptr) _gr_fmpz_poly_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fmpz_poly_ctx_gen_names_srcptr},
 
     {GR_METHOD_INIT,            (gr_funcptr) _gr_fmpz_poly_init},
     {GR_METHOD_CLEAR,           (gr_funcptr) _gr_fmpz_poly_clear},
diff --git a/src/gr/fmpzi.c b/src/gr/fmpzi.c
@@ -24,6 +24,13 @@ _gr_fmpzi_ctx_write(gr_stream_t out, gr_ctx_t ctx)
     return GR_SUCCESS;
 }
 
+char const * const *
+_gr_fmpzi_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    static const char * name = "I";
+    return &name;
+}
+
 void
 _gr_fmpzi_init(fmpzi_t x, const gr_ctx_t ctx)
 {
@@ -951,6 +958,8 @@ gr_method_tab_input _fmpzi_methods_input[] =
     {GR_METHOD_CTX_IS_EXACT,    (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_CANONICAL,
                                 (gr_funcptr) gr_generic_ctx_predicate_true},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR,  (gr_funcptr) _gr_fmpzi_ctx_gen_names_srcptr},
     {GR_METHOD_INIT,            (gr_funcptr) _gr_fmpzi_init},
     {GR_METHOD_CLEAR,           (gr_funcptr) _gr_fmpzi_clear},
     {GR_METHOD_SWAP,            (gr_funcptr) _gr_fmpzi_swap},
diff --git a/src/gr/fq.c b/src/gr/fq.c
@@ -58,6 +58,12 @@ int _gr_fq_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_fq_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_fq_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &FQ_CTX(ctx)->var;
+}
+
 void
 _gr_fq_init(fq_t x, const gr_ctx_t ctx)
 {
@@ -716,6 +722,8 @@ gr_method_tab_input _fq_methods_input[] =
     {GR_METHOD_CTX_WRITE,       (gr_funcptr) _gr_fq_ctx_write},
     {GR_METHOD_CTX_SET_GEN_NAME,    (gr_funcptr) _gr_fq_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES,   (gr_funcptr) _gr_fq_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fq_ctx_gen_names_srcptr},
     {GR_METHOD_CTX_IS_RING,     (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_COMMUTATIVE_RING, (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_INTEGRAL_DOMAIN,  (gr_funcptr) gr_generic_ctx_predicate_true},
diff --git a/src/gr/fq_nmod.c b/src/gr/fq_nmod.c
@@ -59,6 +59,12 @@ int _gr_fq_nmod_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_fq_nmod_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_fq_nmod_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &FQ_CTX(ctx)->var;
+}
+
 void
 _gr_fq_nmod_init(fq_nmod_t x, const gr_ctx_t ctx)
 {
@@ -679,6 +685,8 @@ gr_method_tab_input _fq_nmod_methods_input[] =
     {GR_METHOD_CTX_WRITE,       (gr_funcptr) _gr_fq_nmod_ctx_write},
     {GR_METHOD_CTX_SET_GEN_NAME,    (gr_funcptr) _gr_fq_nmod_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES,   (gr_funcptr) _gr_fq_nmod_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fq_nmod_ctx_gen_names_srcptr},
     {GR_METHOD_CTX_IS_RING,     (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_COMMUTATIVE_RING, (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_INTEGRAL_DOMAIN,  (gr_funcptr) gr_generic_ctx_predicate_true},
diff --git a/src/gr/fq_zech.c b/src/gr/fq_zech.c
@@ -60,6 +60,12 @@ int _gr_fq_zech_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_fq_zech_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_fq_zech_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &FQ_CTX(ctx)->fq_nmod_ctx->var;
+}
+
 void
 _gr_fq_zech_init(fq_zech_t x, const gr_ctx_t ctx)
 {
@@ -560,6 +566,8 @@ gr_method_tab_input _fq_zech_methods_input[] =
     {GR_METHOD_CTX_WRITE,       (gr_funcptr) _gr_fq_zech_ctx_write},
     {GR_METHOD_CTX_SET_GEN_NAME,    (gr_funcptr) _gr_fq_zech_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES,   (gr_funcptr) _gr_fq_zech_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_fq_zech_ctx_gen_names_srcptr},
     {GR_METHOD_CTX_IS_RING,     (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_COMMUTATIVE_RING, (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_IS_INTEGRAL_DOMAIN,  (gr_funcptr) gr_generic_ctx_predicate_true},
diff --git a/src/gr/nf.c b/src/gr/nf.c
@@ -59,6 +59,12 @@ int _gr_nf_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_nf_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_nf_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &NF_VAR(ctx);
+}
+
 void
 _gr_nf_ctx_clear(gr_ctx_t ctx)
 {
@@ -541,6 +547,8 @@ gr_method_tab_input _nf_methods_input[] =
                                 (gr_funcptr) gr_generic_ctx_predicate_true},
     {GR_METHOD_CTX_SET_GEN_NAME, (gr_funcptr) _gr_nf_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES,(gr_funcptr) _gr_nf_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,       (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_nf_ctx_gen_names_srcptr},
     {GR_METHOD_INIT,            (gr_funcptr) _gr_nf_init},
     {GR_METHOD_CLEAR,           (gr_funcptr) _gr_nf_clear},
     {GR_METHOD_SWAP,            (gr_funcptr) _gr_nf_swap},
diff --git a/src/gr/polynomial.c b/src/gr/polynomial.c
@@ -52,6 +52,12 @@ int _gr_gr_poly_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_gr_poly_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_gr_poly_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &POLYNOMIAL_CTX(ctx)->var;
+}
+
 void
 polynomial_ctx_clear(gr_ctx_t ctx)
 {
@@ -660,6 +666,8 @@ gr_method_tab_input _gr_poly_methods_input[] =
     {GR_METHOD_CTX_IS_THREADSAFE,       (gr_funcptr) polynomial_ctx_is_threadsafe},
     {GR_METHOD_CTX_SET_GEN_NAME,        (gr_funcptr) _gr_gr_poly_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES,       (gr_funcptr) _gr_gr_poly_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,               (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR,    (gr_funcptr) _gr_gr_poly_ctx_gen_names_srcptr},
 
     {GR_METHOD_INIT,        (gr_funcptr) polynomial_init},
     {GR_METHOD_CLEAR,       (gr_funcptr) polynomial_clear},
diff --git a/src/gr/series.c b/src/gr/series.c
@@ -1777,6 +1777,11 @@ int _gr_gr_series_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_gr_series_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_gr_series_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &SERIES_CTX(ctx)->var;
+}
 
 static int
 _gr_gr_series_gens_recursive(gr_vec_t vec, gr_ctx_t ctx)
@@ -1951,6 +1956,8 @@ gr_method_tab_input _gr_series_methods_input[] =
     {GR_METHOD_CTX_WRITE,   (gr_funcptr) _gr_gr_series_ctx_write},
     {GR_METHOD_CTX_SET_GEN_NAME, (gr_funcptr) _gr_gr_series_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES, (gr_funcptr) _gr_gr_series_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,   (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_gr_series_ctx_gen_names_srcptr},
     {GR_METHOD_CTX_IS_RING, (gr_funcptr) _gr_gr_series_ctx_is_ring},
     {GR_METHOD_CTX_IS_COMMUTATIVE_RING, (gr_funcptr) _gr_gr_series_ctx_is_commutative_ring},
     {GR_METHOD_INIT,        (gr_funcptr) _gr_gr_series_init},
diff --git a/src/gr/series_mod.c b/src/gr/series_mod.c
@@ -88,6 +88,12 @@ int _gr_gr_series_mod_ctx_set_gen_names(gr_ctx_t ctx, const char ** s)
     return _gr_gr_series_mod_ctx_set_gen_name(ctx, s[0]);
 }
 
+char const * const *
+_gr_gr_series_mod_ctx_gen_names_srcptr(gr_ctx_t ctx)
+{
+    return (char const * const *) &SERIES_MOD_CTX(ctx)->var;
+}
+
 static int
 _gr_gr_series_mod_gens_recursive(gr_vec_t vec, gr_ctx_t ctx)
 {
@@ -371,6 +377,8 @@ gr_method_tab_input _gr_series_mod_methods_input[] =
     {GR_METHOD_CTX_WRITE,   (gr_funcptr) _gr_gr_series_mod_ctx_write},
     {GR_METHOD_CTX_SET_GEN_NAME, (gr_funcptr) _gr_gr_series_mod_ctx_set_gen_name},
     {GR_METHOD_CTX_SET_GEN_NAMES, (gr_funcptr) _gr_gr_series_mod_ctx_set_gen_names},
+    {GR_METHOD_CTX_NGENS,   (gr_funcptr) gr_generic_ctx_ngens_1},
+    {GR_METHOD_CTX_GEN_NAMES_SRCPTR, (gr_funcptr) _gr_gr_series_mod_ctx_gen_names_srcptr},
     {GR_METHOD_CTX_IS_RING, (gr_funcptr) _gr_gr_series_mod_ctx_is_ring},
     {GR_METHOD_CTX_IS_COMMUTATIVE_RING, (gr_funcptr) _gr_gr_series_mod_ctx_is_commutative_ring},
     {GR_METHOD_CTX_IS_INTEGRAL_DOMAIN, (gr_funcptr) _gr_gr_series_mod_ctx_is_integral_domain},
diff --git a/src/gr/test_ring.c b/src/gr/test_ring.c
@@ -10,6 +10,7 @@
 */
 
 #include <stdio.h>
+#include <string.h>
 #include "profiler.h"
 #include "long_extras.h"
 
@@ -650,6 +651,42 @@ gr_test_ctx_get_str(gr_ctx_t R, flint_rand_t state, int test_flags)
     return status;
 }
 
+int
+gr_test_ctx_gen_names(gr_ctx_t R, flint_rand_t state, int test_flags)
+{
+    int status = GR_SUCCESS;
+
+    gr_vec_t gens;
+    gr_vec_init(gens, 0, R);
+
+    slong ngens = gr_ctx_ngens(R);
+    char const * const * names = gr_ctx_gen_names_srcptr(R);
+
+    if (ngens < 0)
+        status = GR_TEST_FAIL;
+
+    if (gr_gens(gens, R) == GR_SUCCESS)
+        if (gens->length != ngens)
+            status = GR_TEST_FAIL;
+
+    const char * mynames[] = { "α", "x", "x1" };
+
+    if (ngens <= 3 && gr_ctx_set_gen_names(R, mynames) == GR_SUCCESS)
+    {
+        names = gr_ctx_gen_names_srcptr(R);
+        for (slong i = 0; i < ngens; i++)
+            if (strcmp(mynames[i], names[i]))
+                status = GR_TEST_FAIL;
+    }
+
+    if (status == GR_TEST_FAIL)
+        flint_printf("gen_names\n");
+
+    gr_vec_clear(gens, R);
+
+    return status;
+}
+
 int
 gr_test_get_set_str(gr_ctx_t R, flint_rand_t state, int test_flags)
 {
@@ -4360,6 +4397,7 @@ gr_test_ring(gr_ctx_t R, slong iters, int test_flags)
         flint_abort(); */
 
     gr_test_iter(R, state, "ctx_get_str", gr_test_ctx_get_str, 1, test_flags);
+    gr_test_iter(R, state, "ctx_gen_names", gr_test_ctx_gen_names, 1, test_flags);
 
     gr_test_iter(R, state, "init/clear", gr_test_init_clear, iters, test_flags);
     gr_test_iter(R, state, "equal", gr_test_equal, iters, test_flags);
diff --git a/src/gr_generic.h b/src/gr_generic.h
@@ -86,6 +86,10 @@ truth_t gr_generic_ctx_predicate_false(gr_ctx_t ctx);
 
 WARN_UNUSED_RESULT int gr_generic_ctx_clear(gr_ctx_t ctx);
 
+slong gr_generic_ctx_ngens_0(gr_ctx_t ctx);
+slong gr_generic_ctx_ngens_1(gr_ctx_t ctx);
+char const * const * gr_generic_ctx_gen_names_srcptr(gr_ctx_t ctx);
+
 void gr_generic_set_shallow(gr_ptr res, gr_srcptr x, const gr_ctx_t ctx);
 
 WARN_UNUSED_RESULT int gr_generic_write_n(gr_stream_t out, gr_srcptr x, slong n, gr_ctx_t ctx);
diff --git a/src/gr_generic/generic.c b/src/gr_generic/generic.c
diff --git a/src/gr_mpoly/ctx.c b/src/gr_mpoly/ctx.c
