Add basic collections.namedtuple implementation.

1 files changed, 144 insertions, 0 deletions

diff --git a/py/objnamedtuple.c b/py/objnamedtuple.c
new file mode 100644
index 000000000..41502fcc4
--- /dev/null
+++ b/py/objnamedtuple.c
@@ -0,0 +1,144 @@
+#include <string.h>
+
+#include "misc.h"
+#include "mpconfig.h"
+#include "nlr.h"
+#include "qstr.h"
+#include "obj.h"
+#include "objtuple.h"
+
+typedef struct _mp_obj_namedtuple_type_t {
+    mp_obj_type_t base;
+    const char *fields;
+} mp_obj_namedtuple_type_t;
+
+typedef struct _mp_obj_namedtuple_t {
+    mp_obj_tuple_t tuple;
+} mp_obj_namedtuple_t;
+
+static inline bool is_end_tok(char c) {
+    return c == ' ' || c == ',';
+}
+
+static inline const char *skip_to_next(const char *p) {
+    while (!is_end_tok(*p)) {
+        if (*p == 0) {
+            return NULL;
+        }
+        p++;
+    }
+    while (is_end_tok(*p)) {
+        if (*p == 0) {
+            return NULL;
+        }
+        p++;
+    }
+    return p;
+}
+
+STATIC uint namedtuple_count_fields(const char *namedef) {
+    uint cnt = 0;
+    while (*namedef != 0) {
+        cnt++;
+        while (!is_end_tok(*namedef) && *namedef != 0) {
+            namedef++;
+        }
+        while (is_end_tok(*namedef) && *namedef != 0) {
+            namedef++;
+        }
+    }
+    return cnt;
+}
+
+STATIC int namedtuple_find_field(const char *name, const char *namedef) {
+    int id = 0;
+    int len = strlen(name);
+    while (namedef) {
+        if (memcmp(name, namedef, len) == 0) {
+            namedef += len;
+            if (*namedef == 0 || is_end_tok(*namedef)) {
+                return id;
+            }
+        }
+        namedef = skip_to_next(namedef);
+        id++;
+    }
+
+    return -1;
+}
+
+STATIC void namedtuple_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
+    mp_obj_namedtuple_t *o = o_in;
+    print(env, "%s(", qstr_str(o->tuple.base.type->name));
+    const char *fields = ((mp_obj_namedtuple_type_t*)o->tuple.base.type)->fields;
+
+    for (int i = 0; i < o->tuple.len; i++) {
+        if (i > 0) {
+                print(env, ", ");
+        }
+        const char *next = fields;
+
+        while (!is_end_tok(*next) && *next != 0) {
+            next++;
+        }
+        print(env, "%.*s=", next - fields, fields);
+        mp_obj_print_helper(print, env, o->tuple.items[i], PRINT_REPR);
+        while (is_end_tok(*next) && *next != 0) {
+            next++;
+        }
+        fields = next;
+    }
+    print(env, ")");
+}
+
+STATIC void namedtuple_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
+    mp_obj_namedtuple_t *self = self_in;
+    const char *fields = ((mp_obj_namedtuple_type_t*)self->tuple.base.type)->fields;
+    int id = namedtuple_find_field(qstr_str(attr), fields);
+    if (id < 0) {
+        return;
+    }
+    dest[0] = self->tuple.items[id];
+}
+
+STATIC bool namedtuple_store_attr(mp_obj_t self_in, qstr attr, mp_obj_t value) {
+    nlr_jump(mp_obj_new_exception_msg(&mp_type_AttributeError, "can't set attribute"));
+}
+
+STATIC mp_obj_t namedtuple_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
+    mp_obj_namedtuple_type_t *type = type_in;
+    uint num_fields = namedtuple_count_fields(type->fields);
+    if (n_args != num_fields) {
+        // Counts include implicit "self"
+        nlr_jump(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
+                                               "__new__() takes %d positional arguments but %d were given",
+                                               num_fields + 1, n_args + 1));
+    }
+    mp_obj_tuple_t *tuple = mp_obj_new_tuple(n_args, args);
+    tuple->base.type = type_in;
+    return tuple;
+}
+
+STATIC const mp_obj_tuple_t namedtuple_base_tuple = {{&tuple_type}, 1, {(mp_obj_t)&tuple_type}};
+
+mp_obj_t mp_obj_new_namedtuple_type(qstr name, const char *fields) {
+    mp_obj_namedtuple_type_t *o = m_new0(mp_obj_namedtuple_type_t, 1);
+    o->base.base.type = &mp_type_type;
+    o->base.name = name;
+    o->base.print = namedtuple_print;
+    o->base.make_new = namedtuple_make_new;
+//    o->base.unary_op = ;
+//    o->base.binary_op = ;
+    o->base.load_attr = namedtuple_load_attr;
+    o->base.store_attr = namedtuple_store_attr;
+    o->base.bases_tuple = (mp_obj_t)&namedtuple_base_tuple;
+    o->fields = fields;
+    return o;
+}
+
+STATIC mp_obj_t new_namedtuple_type(mp_obj_t name_in, mp_obj_t fields_in) {
+    qstr name = MP_OBJ_QSTR_VALUE(name_in);
+    const char *fields = mp_obj_str_get_str(fields_in);
+    return mp_obj_new_namedtuple_type(name, fields);
+}
+MP_DEFINE_CONST_FUN_OBJ_2(mp_namedtuple_obj, new_namedtuple_type);