Add support for double notation eg. 1234. => 1234 0 on the stack.

README.md

@@ -142,14 +142,13 @@ Regardless of the current value of `BASE`, it is possible to input numbers in on
 
 When current `BASE` is ten (10) its possible to input floating point numbers (provided support is enabled) with a decimal point and/or scientific notation.  For example:
 
-         0.0    =  0.  =  0E0  =  0e0
-         1.0    =  1.  =  1E0  =  1e0  =  +1.E0
+         0.0    =  0E0  =  0e0
+         1.0    =  1E0  =  1e0  =  +1.E0
          12.3   =  123E-1
         -0.123  = -123e-3
 
 Floating point numbers are placed on the float stack, which is separate from the data and return stacks.  Also the float stack is small, though at least six (6) deep.  See [Floating-Point Words](./doc/float.md), in particular words [f.](./doc/float.md) and [fs.](./doc/float.md) to start with.
 
-- *Note the double-cell input notation, `1234.` (equivalent to `1234 0`), is not supported.*
 - *Note the input notation, `123E`, where there is no value following the exponent is not supported.*
 
 It is also possible to input a character constant or backslash escape character.  Simple use single-quotes around the character or backslash-escape string (see also `CHAR` and `[CHAR]`).  For example:

src/post4.c

@@ -218,10 +218,11 @@ p4Base36(int digit)
 }
 
 int
-p4StrNum(P4_String str, int base, P4_Cell *out, int *is_float)
+p4StrNum(P4_String str, int base, P4_Cell *out, int *is_float, int *is_double)
 {
 	size_t offset = 0;
 	*is_float = 0;
+	*is_double = 0;
 	if (str.length == 0) {
 		return -1;
 	}
@@ -254,6 +255,11 @@ p4StrNum(P4_String str, int base, P4_Cell *out, int *is_float)
 	for (num.n = 0; offset < str.length; offset++) {
 		int digit = p4Base36(str.string[offset]);
 		if (base <= digit) {
+			/* Support small integer double notation 123. => 123 0 */
+			if (offset + 1 == str.length && str.string[offset] == '.') {
+				*is_double = 1;
+				break;
+			}
 #ifdef HAVE_MATH_H
 			char *stop;
 			/* We don't accept the double-cell notation 123. 0.
@@ -1345,8 +1351,8 @@ _inter_loop:	while (ctx->input->offset < ctx->input->length) {
 			}
 			word = p4FindName(ctx, str.string, str.length);
 			if (word == NULL) {
-				int is_float;
-				if (p4StrNum(str, ctx->radix, &x, &is_float)) {
+				int is_float, is_double;
+				if (p4StrNum(str, ctx->radix, &x, &is_float, &is_double)) {
 					/* Not a word, not a number. */
 					THROW(P4_THROW_UNDEFINED);
 				}
@@ -1367,9 +1373,16 @@ _inter_loop:	while (ctx->input->offset < ctx->input->length) {
 				if (ctx->state == P4_STATE_COMPILE) {
 					p4WordAppend(ctx, (P4_Cell) &w_lit);
 					p4WordAppend(ctx, x);
+					if (is_double) {
+						p4WordAppend(ctx, (P4_Cell) &w_lit);
+						p4WordAppend(ctx, (P4_Cell) 0L);
+					}
 				} else {
 					p4StackIsFull(ctx, &ctx->ds, P4_THROW_DS_OVER);
 					P4_PUSH(ctx->ds, x);
+					if (is_double) {
+						P4_PUSH(ctx->ds, (P4_Cell) 0L);
+					}
 				}
 			} else if (ctx->state == P4_STATE_INTERPRET && P4_WORD_IS(word, P4_BIT_COMPILE)) {
 				THROW(P4_THROW_COMPILE_ONLY);

src/post4.h

@@ -705,7 +705,7 @@ extern int p4CharLiteral(int ch);
  */
 extern void p4StrRev(P4_Char *s, P4_Size length);
 
-extern int p4StrNum(P4_String str, int base, P4_Cell *out, int *is_float);
+extern int p4StrNum(P4_String str, int base, P4_Cell *out, int *is_float, int *is_double);
 
 extern int p4Accept(P4_Input *source, char *buffer, size_t size);