Rearrange the file tree.

[u/mdw/catacomb] / math / field.c

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+/* -*-c-*-
+ *
+ * Abstract field operations
+ *
+ * (c) 2001 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include "field.h"
+#include "mp.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @field_id@ --- *
+ *
+ * Arguments:  @field *f@ = pointer to a field
+ *             @mp *d@ = a destination element
+ *             @mp *x@ = a source element
+ *
+ * Returns:    The result element.
+ *
+ * Use:                An identity operation which can be used if your field has no
+ *             internal representation.
+ */
+
+mp *field_id(field *f, mp *d, mp *x)
+  { x = MP_COPY(x); if (d) MP_DROP(d); return (x); }
+
+/* --- @field_samep@ --- *
+ *
+ * Arguments:  @field *f, *g@ = two fields
+ *
+ * Returns:    Nonzero if the fields are identical (not just isomorphic).
+ *
+ * Use:                Checks for sameness of fields.  This function does the full
+ *             check, not just the field-type-specific check done by the
+ *             @sampep@ field operation.
+ */
+
+int field_samep(field *f, field *g)
+  { return (f == g || (f->ops == g->ops && F_SAMEP(f, g))); }
+
+/* --- @field_stdsamep@ --- *
+ *
+ * Arguments:  @field *f, *g@ = two fields
+ *
+ * Returns:    Nonzero if the fields are identical (not just isomorphic).
+ *
+ * Use:                Standard sameness check, based on equality of the @m@
+ *             member.
+ */
+
+int field_stdsamep(field *f, field *g) { return (MP_EQ(f->m, g->m)); }
+
+/*----- That's all, folks -------------------------------------------------*/