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, 6 insertions, 4 deletions

diff --git a/src/parser.c b/src/parser.c
index 45e1e3c..231ad3e 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -792,15 +792,17 @@ teco_state_stringbuilding_ctle_num_input(teco_machine_stringbuilding_t *ctx, gun
 		/* parse-only mode */
 		return &teco_state_stringbuilding_start;
 
-	teco_int_t value;
-	if (!qreg->vtable->get_integer(qreg, &value, error))
+	teco_number_t value;
+	gboolean is_float;
+	if (!qreg->vtable->get_number(qreg, &value, &is_float, error))
 		return NULL;
 
 	/*
 	 * NOTE: Numbers can always be safely formatted as null-terminated strings.
 	 */
 	gchar buffer[TECO_EXPRESSIONS_FORMAT_LEN];
-	const gchar *num = teco_expressions_format(buffer, value, ctx->qreg_table_locals->radix);
+	const gchar *num = is_float ? teco_expressions_format_float(buffer, value.f, 6)
+	                            : teco_expressions_format_int(buffer, value.i, ctx->qreg_table_locals->radix);
 	teco_machine_stringbuilding_append(ctx, num, strlen(num));
 
 	return &teco_state_stringbuilding_start;
@@ -830,7 +832,7 @@ teco_state_stringbuilding_ctle_u_input(teco_machine_stringbuilding_t *ctx, gunic
 		return &teco_state_stringbuilding_start;
 
 	teco_int_t value;
-	if (!qreg->vtable->get_integer(qreg, &value, error))
+	if (!teco_qreg_get_integer(qreg, &value, error))
 		return NULL;
 
 	if (!teco_machine_stringbuilding_append_c(ctx, value)) {