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Commit ec0b33f1 authored by Dirk Zimoch's avatar Dirk Zimoch
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add string slices

parent 03d1c875
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expr.c
+ 129
− 33
View file @ ec0b33f1
......@@ -7,10 +7,12 @@
int exprDebug;
static int parseSubExpr(const char** pp, long* v, int pr, int op);
static int parseSubExpr(const char **pp, long *v, int pr, int op);
#define parseExpr(pp,v) parseSubExpr(pp, v, 0, 0)
static int parseValue(const char** pp, long* v)
#define skipSpace(p) while (isspace((unsigned char)*p)) p++
static int parseValue(const char **pp, long *v)
{
long val;
const char *p = *pp;
......@@ -23,7 +25,7 @@ static int parseValue(const char** pp, long* v)
*/
/* first look for value */
while (isspace((unsigned char)*p)) p++;
skipSpace(p);
o = *p;
if (memchr("+-~!", o, 4))
{
......@@ -39,20 +41,20 @@ static int parseValue(const char** pp, long* v)
/* handle sub-expression */
p++;
if (parseExpr(&p, &val) < 0) return 0; /* no valid expression */
while (isspace((unsigned char)*p)) p++;
skipSpace(p);
if (*p++ != ')') return 0; /* missing ) */
}
else
{
/* get number */
char* e;
char *e;
val = strtol(p, &e, 0);
if (e == p) return 0; /* no number */
if (isalpha((unsigned char)*e)||*e=='.')
{
/* followed by rubbish */
return 0;
/* part of plain word or floating point number */
return 0;
}
p = e;
}
......@@ -71,6 +73,16 @@ static long ipow(long base, long exp)
return v;
}
static char parseSep(const char **pp, const char *seps)
{
const char *p = *pp;
skipSpace(p);
if (!*p || !strchr(seps, *p)) return 0;
*pp = p+1;
return *p;
}
struct {char str[4]; int pr;} ops[] = {
{"",0},
{"**",11},
......@@ -81,22 +93,22 @@ struct {char str[4]; int pr;} ops[] = {
{"==",6},{"!=",6},
{"&&",5},{"||",5},
{"&",4},{"^",3},{"|",2},
{"?:",1},{"?",1},{":",0}
{"?:",1},{"?",1}
};
static int startsWith(const char* p, const char* s)
static int startsWith(const char *p, const char *s)
{
int i = 0;
while (*s) { i++; if (*p++ != *s++) return 0; }
return i;
}
static int parseOp(const char** pp)
static int parseOp(const char **pp)
{
const char *p = *pp;
int o, l;
while (isspace((unsigned char)*p)) p++;
skipSpace(p);
if (ispunct((unsigned char)*p))
{
for (o = 1; o < (int)(sizeof(ops)/sizeof(ops[0])); o++)
......@@ -112,7 +124,7 @@ static int parseOp(const char** pp)
return 0;
}
static int parseSubExpr(const char** pp, long* v, int pr, int o)
static int parseSubExpr(const char **pp, long *v, int pr, int o)
{
const char *p = *pp;
long val = o ? *v : 0;
......@@ -123,7 +135,11 @@ static int parseSubExpr(const char** pp, long* v, int pr, int o)
do {
if (!parseValue(&p, &val2))
{
if (exprDebug) printf("parseExpr(%d): no value after %ld %s\n", pr, val, ops[o].str);
if (exprDebug)
{
if (o) printf("parseExpr(%d): no value after %ld %s\n", pr, val, ops[o].str);
else printf("parseExpr(%d): no value\n", pr);
}
return -1;
}
if ((o2 = parseOp(&p)))
......@@ -171,11 +187,17 @@ static int parseSubExpr(const char** pp, long* v, int pr, int o)
long val3 = 0;
val2 = 1;
if (exprDebug) printf("parseExpr(%d) if %ld ...\n", pr, val);
if ((o2 = parseSubExpr(&p, &val2, 1, 0)) == 24)
o2 = parseSubExpr(&p, &val3, 1, 0);
else o2 = 0;
if (parseExpr(&p, &val2) >= 0)
{
if (parseSep(&p, ":"))
{
if (exprDebug) printf("parseExpr(%d) : found\n", pr);
parseExpr(&p, &val3);
}
}
if (exprDebug) printf("parseExpr(%d) if %ld then %ld else %ld\n", pr, val, val2, val3);
val = val ? val2 : val3;
break;
}
o = o2;
} while (ops[o].pr && pr <= ops[o].pr);
......@@ -185,10 +207,10 @@ static int parseSubExpr(const char** pp, long* v, int pr, int o)
return o;
}
const char* getFormat(const char** pp)
const char *getFormat(const char **pp)
{
static char format [20];
const char* p = *pp;
const char *p = *pp;
unsigned int i = 1;
if (exprDebug) printf("getFormat %s\n", p);
if ((format[0] = *p++) == '%')
......@@ -212,11 +234,81 @@ const char* getFormat(const char** pp)
return NULL;
}
size_t replaceExpressions(const char* r, char* buffer, size_t buffersize)
int parseSlice(const char **pp, long* pstart, long* plength)
{
const char *p = *pp;
long slice_start = 0;
long slice_length = 0;
long string_length = *plength;
char o;
if (*p++ != '[') return 0;
parseExpr(&p, &slice_start);
if (slice_start < 0) slice_start += string_length;
if ((o = parseSep(&p, ":,"))) /* [start,length] or [start:end] */
{
parseExpr(&p, &slice_length);
if (o == ':')
{
if (slice_length < 0) slice_length += string_length;
slice_length -= slice_start;
}
}
else slice_length = 1;
if (slice_start < 0)
{
slice_length += slice_start;
slice_start = 0;
}
if (slice_start > string_length)
slice_length = 0;
if (slice_length > string_length - slice_start)
slice_length = string_length - slice_start;
if (slice_length < 0)
slice_length = 0;
skipSpace(p);
if (*p++ != ']') return 0;
*pstart += slice_start;
*plength = slice_length;
*pp = p;
return 1;
}
long parseString(const char **pp, const char **pstart)
{
const char *p = *pp;
const char *string_start = p;
long slice_start = 0;
long length = 0;
char q;
q = *p++;
while (*p) /* string length with escapes */
{
if (*p == '\\')
if (*++p == 0) break;
if (*p++ == q) break;
length++;
}
while (parseSlice(&p, &slice_start, &length));
if (exprDebug) printf("parseString %.*s[%ld,%ld]\n", (int)(p-string_start), string_start, slice_start, length);
if (length && pstart)
{
while (slice_start-- > 0)
{
if (*string_start++ == '\\') string_start++;
}
*pstart = ++string_start;
}
*pp = p;
return length;
}
size_t replaceExpressions(const char *r, char *buffer, size_t buffersize)
{
long val;
char* w = buffer;
char* s;
char *w = buffer;
char *s;
*w = 0;
while (*r)
......@@ -225,22 +317,26 @@ size_t replaceExpressions(const char* r, char* buffer, size_t buffersize)
if (*r == '"' || *r == '\'')
{
/* quoted strings */
char c = *w++ = *r++;
while (*r && *r != c) {
if (*r == '\\' && !(*w++ = *r++)) break;
*w++ = *r++;
const char *start;
char q = *r;
long length = parseString(&r, &start);
*w++ = q;
while (length-- > 0)
{
if (*start == '\\') *w++ = *start++;
*w++ = *start++;
}
if (*r) *w++ = *r++;
*w = 0;
*w++ = q;
*w++ = 0;
if (exprDebug) printf("quoted string %s\n", s);
}
else if (*r == '%')
{
/* formatted expression */
const char* r2 = r;
const char* f;
const char *r2 = r;
const char *f;
if (exprDebug) printf("formatted expression after '%s'\n", s);
if ((f = getFormat(&r2)) && parseExpr(&r2, &val) == 0)
if ((f = getFormat(&r2)) && parseExpr(&r2, &val) >= 0)
{
r = r2;
if (w > buffer && w[-1] == '(' && *r2++ == ')')
......@@ -252,7 +348,7 @@ size_t replaceExpressions(const char* r, char* buffer, size_t buffersize)
if (exprDebug) printf("formatted expression %s\n", s);
}
}
else if (parseExpr(&r, &val) == 0)
else if (parseExpr(&r, &val) >= 0)
{
/* unformatted expression */
w += sprintf(w, "%ld", val);
......@@ -267,7 +363,7 @@ size_t replaceExpressions(const char* r, char* buffer, size_t buffersize)
else {
/* unquoted string (i.e plain word) */
do {
*w++ = *r++;
if ((*w++ = *r++) == '\\') if (*r) *w++ = *r++;
} while (*r && !strchr("%(\"', \t\n", *r));
*w = 0;
if (exprDebug) printf("plain word '%s'\n", s);
......
testscript
+ 6
− 7
View file @ ec0b33f1
#var exprDebug 1
x=3, !3, -3, ~3, 3?
# $(x) should be: 3, 0, -3, -4, 1
x=3, !3, !!3, -3, --3, ~3, ~~3, 3?, 3??
# $(x) should be: 3, 0, 1, -3, 3, -4, 3, 1, 1
x=x, !x, !!x, -x, --x, ~x, ~~x, x?, x??
# $(x) should be: x, !x, !!x, -x, --x, ~x, ~~x, x?, x??
x=10+3, 10-3, 10*3, 10/3, 10%3, 10**3
# $(x) should be: 13, 7, 30, 3, 1, 1000
......@@ -57,13 +60,10 @@ x=7 ? -1
x=0 ? -1
# $(x) should be: 0
x=1+0?0?1:2:3?4:5
# $(x) should be: 2
x=1+0?7?1:2:3?4:5
# $(x) should be: 1
x=1+1?0?1:2:3-3?4:5
x=1+0?0?1:2:3?4:5
# $(x) should be: 2
x=1-1?0?1:2:3?4:5
......@@ -90,4 +90,3 @@ x=-2**2 0-2**2 0+-2**2 0--2**2
x=
y=$(x)
# <$(x)><$(y)> should be: <><>
teststrings 0 → 100644
+ 80
− 0
View file @ ec0b33f1
x=string0
y=$(x)
# $(x) $(y)
x="string1"
y=$(x)
# $(x) $(y)
x="'string2'"
y=$(x)
# $(x) $(y)
x='"string3"'
y=$(x)
# $(x) $(y)
x=\"string4\"
y=$(x)
# $(x) $(y)
x=\'string5\'
y=$(x)
# $(x) $(y)
x="Hello World"[2:8]
# $(x) should be: llo Wo
x=Hello World[2:8]
# "$(x)" should be: "Hello World[2:8]"
x="Hello World"[2,3]
# $(x) should be: llo
x="Hello World"[1]
# $(x) should be: e
x="Hello World"[-1]
# $(x) should be: d
x="Hello World"[-2:]
# $(x) should be: ld
x="Hello World"[-2,6]
# $(x) should be: ld
x="Hello World"[1:1000]
# $(x) should be: ello World
x="Hello World"[1:-1000]
# "$(x)" should be: ""
x="Hello World"[:]
# "$(x)" should be: "Hello World"
x="Hello World"[1?6:0:]
# "$(x)" should be: "World"
x="Hello World"[1000]
# "$(x)" should be: ""
x="Hello World"[-1000]
# "$(x)" should be: ""
x="Hello World"[-1000,1005]
# "$(x)" should be: "World"
x="Hello World"[-1000:5]
# "$(x)" should be: "World"
x="Hello World"[7:4]
# "$(x)" should be: ""
x="Hello World"[1?3+4:0:7-8]
# "$(x)" should be: "orl"
x="Hello World"[7,-1]
# "$(x)" should be: ""
x='\"\\x'[2]
# $(x) should be: x
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