support floating point numbers

* Extends the SciTECO type system. A number on the expression stack
  or in a Q-register can be either an integer or a float.
* Floating point constants begin with a digit (like all other
  numbers), are followed by a `.` and an optional fractional part.
  Exponents cannot currently be written.
  E.g. `1.` == `1.0`. But `.0` would still be `.,0`.
  (!) To push an integer followed by dot, you must now write e.g. `1,.` or `1 .`.
* All of the basic arithmetic operators operate like this:
  If both operands are integers, the result is also an integer (integer arithmetics).
  If at least one of the operands is a float, the result is also a float (float arithmetics).
* All of the binary operators (AND, OR, XOR) always cast all
  operands to integer and the result is always an integer as well.
* You can "cast" integers to float by `*1.` or `/1.`.
  You can "cast" floats to integers using `#0`.
* Most commands still accept only integers. Floats are implicitly casted to integers.
  Float-aware commands are: =, \, ^W, Qq, Uq, %q and the conditionals.
* `%q` will not change the current type of register q.
* Numeric part of "lexer.font" is now a float (in points).
* You cannot currently print octal and hexadecimal floats.
  `==` and `===` are identical to `=` on floats.
* `===` is now printing hex integers in lower case.
  This is because SciTECO's coding style for hex constants is also lower case.
* `--with-teco-integer` renamed to `--with-teco-number`.

1 files changed, 48 insertions, 20 deletions

diff --git a/src/qreg.h b/src/qreg.h
index 1eb2cf8..cbd6b2c 100644
--- a/src/qreg.h
+++ b/src/qreg.h
@@ -54,9 +54,15 @@ extern teco_view_t *teco_qreg_view;
  * FIXME: We can probably get rid of all the separate undo callbacks/methods.
  */
 typedef const struct {
+	/*
+	 * FIXME: perhaps there should only be a set_number() callback with some
+	 * teco_qreg_set_integer() shortcut.
+	 */
 	/* already pushes undo tokens */
-	gboolean (*set_integer)(teco_qreg_t *qreg, teco_int_t value, GError **error);
-	gboolean (*get_integer)(teco_qreg_t *qreg, teco_int_t *ret, GError **error);
+	gboolean (*set_number)(teco_qreg_t *qreg, teco_number_t value,
+	                       gboolean is_float, GError **error);
+	gboolean (*get_number)(teco_qreg_t *qreg, teco_number_t *ret,
+	                       gboolean *is_float, GError **error);
 
 	gboolean (*set_string)(teco_qreg_t *qreg, const gchar *str, gsize len,
 	                       guint codepage, GError **error);
@@ -100,26 +106,48 @@ struct teco_qreg_t {
 
 	teco_qreg_vtable_t *vtable;
 
-	teco_int_t integer;
+	teco_number_t number;
 	teco_doc_t string;
 
-	/**
-	 * Whether to generate undo tokens (unnecessary for registers
-	 * in local qreg tables in macro invocations).
-	 *
-	 * @fixme Every QRegister has this field, but it only differs
-	 * between local and global QRegisters. This wastes space.
-	 * Or by deferring any decision about undo token creation to a layer
-	 * that knows which table it is accessing.
-	 * On the other hand, we will need another flag like
-	 * teco_qreg_current_must_undo.
-	 *
-	 * Otherwise, it might be possible to use a least significant bit
-	 * in one of the pointers...
-	 */
-	gboolean must_undo;
+	struct teco_qreg_flags_t {
+		/**
+		 * Whether to generate undo tokens (unnecessary for registers
+		 * in local qreg tables in macro invocations).
+		 *
+		 * @fixme Every QRegister has this field, but it only differs
+		 * between local and global QRegisters. This wastes space.
+		 * Or by deferring any decision about undo token creation to a layer
+		 * that knows which table it is accessing.
+		 * On the other hand, we will need another flag like
+		 * teco_qreg_current_must_undo.
+		 *
+		 * Otherwise, it might be possible to use a least significant bit
+		 * in one of the pointers...
+		 */
+		guint must_undo : 1;
+		/** whether the number cell is integer or float_val */
+		guint is_float : 1;
+	} flags;
 };
 
+static inline gboolean
+teco_qreg_set_integer(teco_qreg_t *qreg, teco_int_t value, GError **error)
+{
+	return qreg->vtable->set_number(qreg, (teco_number_t){.i = value}, FALSE, error);
+}
+
+static inline gboolean
+teco_qreg_get_integer(teco_qreg_t *qreg, teco_int_t *ret, GError **error)
+{
+	teco_number_t number;
+	gboolean is_float;
+
+	if (!qreg->vtable->get_number(qreg, &number, &is_float, error))
+		return FALSE;
+	*ret = is_float ? (teco_int_t)number.f : number.i;
+	return TRUE;
+}
+
 teco_qreg_t *teco_qreg_plain_new(const gchar *name, gsize len);
 teco_qreg_t *teco_qreg_dot_new(void);
 teco_qreg_t *teco_qreg_bufferinfo_new(void);
@@ -175,7 +203,7 @@ void teco_qreg_table_init_locals(teco_qreg_table_t *table, gboolean must_undo);
 static inline teco_qreg_t *
 teco_qreg_table_insert(teco_qreg_table_t *table, teco_qreg_t *qreg)
 {
-	qreg->must_undo = table->must_undo; // FIXME
+	qreg->flags.must_undo = table->must_undo; // FIXME
 	return (teco_qreg_t *)teco_rb3str_insert(&table->tree, TRUE, &qreg->head);
 }
 
@@ -242,7 +270,7 @@ teco_qreg_table_get_integer(teco_qreg_table_t *table, const gchar *name,
 		return FALSE;
 	}
 
-	return reg->vtable->get_integer(reg, ret, error);
+	return teco_qreg_get_integer(reg, ret, error);
 }
 
 teco_qreg_t *teco_qreg_table_edit_name(teco_qreg_table_t *table, const gchar *name,