shithub: rgbds

Info  •  Files  •  Log  •  Branches

STRSUB and CHARSUB allow zero or negative positions

These are offsets from the end of the string, as if the
STRLEN or CHARLEN respectively were added to the position.

Fixes #812

--- a/src/asm/parser.y

+++ b/src/asm/parser.y

@@ -105,7 +105,7 @@

 	return len;

 }

-static void strsubUTF8(char *dest, size_t destLen, char const *src, uint32_t pos, uint32_t len)

+static void strsubUTF8(char *dest, size_t destLen, char const *src, int32_t pos, uint32_t len)

 {

 	size_t srcIndex = 0;

 	size_t destIndex = 0;

@@ -114,8 +114,11 @@

 	uint32_t curLen = 0;

 	if (pos < 1) {

-		warning(WARNING_BUILTIN_ARG, "STRSUB: Position starts at 1\n");

-		pos = 1;

+		pos += strlenUTF8(src);

+		if (pos < 1) {

+			warning(WARNING_BUILTIN_ARG, "STRSUB: Position starts at 1\n");

+			pos = 1;

+		}

 	}

 	/* Advance to starting position in source string. */

@@ -132,8 +135,7 @@

 	if (!src[srcIndex] && len)

 		warning(WARNING_BUILTIN_ARG,

-			"STRSUB: Position %lu is past the end of the string\n",

-			(unsigned long)pos);

+			"STRSUB: Position %" PRId32 " is past the end of the string\n", pos);

 	/* Copy from source to destination. */

 	while (src[srcIndex] && destIndex < destLen - 1 && curLen < len) {

@@ -168,13 +170,16 @@

 	return len;

 }

-static void charsubUTF8(char *dest, char const *src, uint32_t pos)

+static void charsubUTF8(char *dest, char const *src, int32_t pos)

 {

 	size_t charLen = 1;

 	if (pos < 1) {

-		warning(WARNING_BUILTIN_ARG, "CHARSUB: Position starts at 1\n");

-		pos = 1;

+		pos += charlenUTF8(src);

+		if (pos < 1) {

+			warning(WARNING_BUILTIN_ARG, "CHARSUB: Position starts at 1\n");

+			pos = 1;

+		}

 	}

 	/* Advance to starting position in source string. */

@@ -185,8 +190,7 @@

 	if (!charmap_ConvertNext(&src, NULL))

 		warning(WARNING_BUILTIN_ARG,

-			"CHARSUB: Position %lu is past the end of the string\n",

-			(unsigned long)pos);

+			"CHARSUB: Position %" PRId32 " is past the end of the string\n", pos);

 	/* Copy from source to destination. */

 	memcpy(dest, start, src - start);

@@ -1526,10 +1530,10 @@

 ;

 string		: T_STRING

-		| T_OP_STRSUB T_LPAREN string T_COMMA uconst T_COMMA uconst T_RPAREN {

+		| T_OP_STRSUB T_LPAREN string T_COMMA const T_COMMA uconst T_RPAREN {

 			strsubUTF8($$, sizeof($$), $3, $5, $7);

 		}

-		| T_OP_CHARSUB T_LPAREN string T_COMMA uconst T_RPAREN {

+		| T_OP_CHARSUB T_LPAREN string T_COMMA const T_RPAREN {

 			charsubUTF8($$, $3, $5);

 		}

 		| T_OP_STRCAT T_LPAREN T_RPAREN {

--- a/src/asm/rgbasm.5

+++ b/src/asm/rgbasm.5

@@ -394,13 +394,13 @@

 .It Fn STRCMP str1 str2 Ta Returns -1 if Ar str1 No is alphabetically lower than Ar str2 No , zero if they match, 1 if Ar str1 No is greater than Ar str2 .

 .It Fn STRIN str1 str2 Ta Returns the first position of Ar str2 No in Ar str1 No or zero if it's not present Pq first character is position 1 .

 .It Fn STRRIN str1 str2 Ta Returns the last position of Ar str2 No in Ar str1 No or zero if it's not present Pq first character is position 1 .

-.It Fn STRSUB str pos len Ta Returns a substring from Ar str No starting at Ar pos No (first character is position 1) and Ar len No characters long.

+.It Fn STRSUB str pos len Ta Returns a substring from Ar str No starting at Ar pos No (first character is position 1) and Ar len No characters long. Zero or negative Ar pos No counts from the end, as if Qo STRLEN(str) Qc were added to it.

 .It Fn STRUPR str Ta Returns Ar str No with all letters in uppercase.

 .It Fn STRLWR str Ta Returns Ar str No with all letters in lowercase.

 .It Fn STRRPL str old new Ta Returns Ar str No with each non-overlapping occurrence of the substring Ar old No replaced with Ar new .

 .It Fn STRFMT fmt args... Ta Returns the string Ar fmt No with each

 .It Fn CHARLEN str Ta Returns the number of charmap entries in Ar str No with the current charmap.

-.It Fn CHARSUB str pos Ta Returns the substring for the charmap entry at Ar pos No in Ar str No (first character is position 1) with the current charmap.

+.It Fn CHARSUB str pos Ta Returns the substring for the charmap entry at Ar pos No in Ar str No (first character is position 1) with the current charmap. Zero or negative Ar pos No counts from the end, as if Qo CHARLEN(str) Qc were added to it.

 .Ql %spec

 pattern replaced by interpolating the format

 .Ar spec

--- a/test/asm/charlen-charsub.asm

+++ b/test/asm/charlen-charsub.asm

@@ -11,6 +11,7 @@

 	assert CHARLEN("{S}") == 6

 	println CHARSUB("{S}", 2)

 	assert !STRCMP(CHARSUB("{S}", 2), "Bold")

+	assert CHARSUB("{S}", -4) == CHARSUB("{S}", CHARLEN("{S}") - 4)

 	assert CHARSUB("{S}", 2) == "Bold" && "Bold" == $88

 	assert CHARSUB("{S}", 1) == $58 ; ASCII "X"

 	db "{S}"

@@ -20,6 +21,7 @@

 	assert CHARLEN("{S}") == 14

 	println CHARSUB("{S}", 2)

 	assert !STRCMP(CHARSUB("{S}", 2), "B")

+	assert CHARSUB("{S}", -4) == CHARSUB("{S}", CHARLEN("{S}") - 4)

 	assert CHARSUB("{S}", 2) == "B" && "B" == $42 ; ASCII "B"

 	assert CHARSUB("{S}", 1) == $58 ; ASCII "X"

 	db "{S}"

--- a/test/asm/strsub.asm

+++ b/test/asm/strsub.asm

@@ -7,11 +7,14 @@

 	xstrsub "ABC", 1, 1

 	xstrsub "ABC", 2, 1

 	xstrsub "ABC", 3, 1

+	xstrsub "ABC", -2, 1

+	xstrsub "ABC", -1, 1

+	xstrsub "ABC", 0, 1

 	xstrsub "ABC", 1, 2

 	xstrsub "ABC", 2, 2

 	xstrsub "ABC", 2, 32

 	xstrsub "ABC", 2, 300

-	xstrsub "ABC", 0, 300

+	xstrsub "ABC", -3, 300

 	xstrsub "ABC", 4, 0

 	xstrsub "ABC", 4, 1

 	xstrsub "カタカナ", 1, 2

--- a/test/asm/strsub.err

+++ b/test/asm/strsub.err

@@ -1,14 +1,14 @@

-warning: strsub.asm(12) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

+warning: strsub.asm(15) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

     STRSUB: Length too big: 32

-warning: strsub.asm(13) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

+warning: strsub.asm(16) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

     STRSUB: Length too big: 300

-warning: strsub.asm(14) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

+warning: strsub.asm(17) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

     STRSUB: Position starts at 1

-warning: strsub.asm(14) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

+warning: strsub.asm(17) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

     STRSUB: Length too big: 300

-warning: strsub.asm(16) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

+warning: strsub.asm(19) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

     STRSUB: Position 4 is past the end of the string

-warning: strsub.asm(16) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

-    STRSUB: Length too big: 1

 warning: strsub.asm(19) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

+    STRSUB: Length too big: 1

+warning: strsub.asm(22) -> strsub.asm::xstrsub(4): [-Wbuiltin-args]

     STRSUB: Length too big: 10

--- a/test/asm/strsub.out

+++ b/test/asm/strsub.out

@@ -1,6 +1,9 @@

 A

 B

 C

+A

+B

+C

 AB

 BC

 BC