ref: da7d6df6faf18e289fe0f3f61524dcc7fddeef18
dir: /appl/lib/string.b/
implement String;
include "sys.m";
include "string.m";
splitl(s: string, cl: string): (string, string)
{
n := len s;
for(j := 0; j < n; j++) {
if(in(s[j], cl))
return (s[0:j], s[j:n]);
}
return (s,"");
}
splitr(s: string, cl: string): (string, string)
{
n := len s;
for(j := n-1; j >= 0; j--) {
if(in(s[j], cl))
return (s[0:j+1], s[j+1:n]);
}
return ("",s);
}
drop(s: string, cl: string): string
{
n := len s;
for(j := 0; j < n; j++) {
if(!in(s[j], cl))
return (s[j:n]);
}
return "";
}
take(s: string, cl: string): string
{
n := len s;
for(j := 0; j < n; j++) {
if(!in(s[j], cl))
return (s[0:j]);
}
return s;
}
in(c: int, s: string): int
{
n := len s;
if(n == 0)
return 0;
ans := 0;
negate := 0;
if(s[0] == '^') {
negate = 1;
s = s[1:];
n--;
}
for(i := 0; i < n; i++) {
if(s[i] == '-' && i > 0 && i < n-1) {
if(c >= s[i-1] && c <= s[i+1]) {
ans = 1;
break;
}
i++;
}
else
if(c == s[i]) {
ans = 1;
break;
}
}
if(negate)
ans = !ans;
return ans;
}
splitstrl(s: string, t: string): (string, string)
{
n := len s;
nt := len t;
if(nt == 0)
return ("", s);
c0 := t[0];
mainloop:
for(j := 0; j <= n-nt; j++) {
if(s[j] == c0) {
for(k := 1; k < nt; k++)
if(s[j+k] != t[k])
continue mainloop;
return(s[0:j], s[j:n]);
}
}
return (s,"");
}
splitstrr(s: string, t: string): (string, string)
{
n := len s;
nt := len t;
if(nt == 0)
return (s, "");
c0 := t[0];
mainloop:
for(j := n-nt; j >= 0; j--) {
if(s[j] == c0) {
for(k := 1; k < nt; k++)
if(s[j+k] != t[k])
continue mainloop;
return(s[0:j+nt], s[j+nt:n]);
}
}
return ("",s);
}
prefix(pre: string, s: string): int
{
if(len s < len pre)
return 0;
for(k := 0; k < len pre; k++)
if(pre[k] != s[k])
return 0;
return 1;
}
tolower(s: string): string
{
for(i := 0; i < len s; i++) {
c := s[i];
if(c >= 'A' && c <= 'Z')
s[i] += 'a' - 'A';
}
return s;
}
toupper(s: string): string
{
for(i := 0; i < len s; i++) {
c := s[i];
if(c >= 'a' && c <= 'z')
s[i] += 'A' - 'a';
}
return s;
}
startnum(s: string, base: int): (int, int, int)
{
if(s == nil || base != 0 && (base < 2 || base > 36))
return (0, 0, 0);
# skip possible leading white space
c := ' ';
for (i := 0; i < len s; i++) {
c = s[i];
if(c != ' ' && c != '\t' && c != '\n')
break;
}
# optional sign
neg := 0;
if(c == '-' || c == '+') {
if(c == '-')
neg = 1;
i++;
}
if(base == 0) {
# parse possible leading base designator
start := i;
base = -1;
for (; i < start+3 && i < len s; i++) {
c = s[i];
if (c == 'r' && i > start) {
base = int s[start:i];
i++;
break;
} else if (c < '0' || c > '9')
break;
}
if (base == -1) {
i = start;
base = 10;
} else if (base == 0 || base > 36)
return (0, 0, i);
}
if(i >= len s)
return (0, 0, 0);
return (base, neg, i);
}
tobig(s: string, base: int): (big, string)
{
neg, i: int;
(base, neg, i) = startnum(s, base);
if(base == 0)
return (big 0, s);
# parse number itself.
# probably this should check for overflow, and max out, as limbo op does?
start := i;
n := big 0;
for (; i < len s; i++) {
if((d := digit(s[i], base)) < 0)
break;
n = n*big base + big d;
}
if (i == start)
return (big 0, s);
if (neg)
return (-n, s[i:]);
return (n, s[i:]);
}
toint(s: string, base: int): (int, string)
{
neg, i: int;
(base, neg, i) = startnum(s, base);
if(base == 0)
return (0, s);
# parse number itself.
# probably this should check for overflow, and max out, as limbo op does?
start := i;
n := 0;
for (; i < len s; i++){
if((d := digit(s[i], base)) < 0)
break;
n = n*base + d;
}
if (i == start)
return (0, s);
if (neg)
return (-n, s[i:]);
return (n, s[i:]);
}
digit(c: int, base: int): int
{
if ('0' <= c && c <= '0' + base - 1)
return c-'0';
else if ('a' <= c && c < 'a' + base - 10)
return (c - 'a' + 10);
else if ('A' <= c && c < 'A' + base - 10)
return (c - 'A' + 10);
else
return -1;
}
rpow(x: real, n: int): real
{
inv := 0;
if(n < 0){
n = -n;
inv = 1;
}
r := 1.0;
for(;;){
if(n&1)
r *= x;
if((n >>= 1) == 0)
break;
x *= x;
}
if(inv)
r = 1.0/r;
return r;
}
match(p: string, s: string, i: int): int
{
if(i+len p > len s)
return 0;
for(j := 0; j < len p; j++){
c := s[i++];
if(c >= 'A' && c <= 'Z')
c += 'a'-'A';
if(p[j] != c)
return 0;
}
return 1;
}
toreal(s: string, base: int): (real, string)
{
neg, i: int;
(base, neg, i) = startnum(s, base);
if(base == 0)
return (0.0, s);
c := s[i];
if((c == 'i' || c == 'I') && match("infinity", s, i))
return (real s, s[i+8:]);
if((c == 'n' || c == 'N') && match("nan", s, i))
return (real s, s[i+3:]);
if(digit(c, base) < 0)
return (0.0, s);
num := 0.0;
for(; i < len s && (d := digit(s[i], base)) >= 0; i++)
num = num*real base + real d;
dig := 0; # digits in fraction
if(i < len s && s[i] == '.'){
i++;
for(; i < len s && (d = digit(s[i], base)) >= 0; i++){
num = num*real base + real d;
dig++;
}
}
exp := 0;
eneg := 0;
if(i < len s && ((c = s[i]) == 'e' || c == 'E')){
start := i; # might still be badly formed
i++;
if(i < len s && ((c = s[i]) == '-' || c == '+')){
i++;
if(c == '-'){
dig = -dig;
eneg = 1;
}
}
if(i < len s && s[i] >= '0' && s[i] <= '9'){ # exponents are always decimal
for(; i < len s && (d = digit(s[i], 10)) >= 0; i++)
exp = exp*base + d;
}else
i = start;
}
if(base == 10)
return (real s[0: i], s[i:]); # conversion can be more accurate
exp -= dig;
if(exp < 0){
exp = -exp;
eneg = !eneg;
}
if(exp < 0 || exp > 19999)
exp = 19999; # huge but otherwise arbitrary limit
dem := rpow(real base, exp);
if(eneg)
num /= dem;
else
num *= dem;
if(neg)
return (-num,s[i:]);
return (num, s[i:]);
}
append(s: string, l: list of string): list of string
{
t: list of string;
# Reverse l, prepend s, and reverse result.
while (l != nil) {
t = hd l :: t;
l = tl l;
}
t = s :: t;
do {
l = hd t :: l;
t = tl t;
} while (t != nil);
return l;
}
quoted(argv: list of string): string
{
return quotedc(argv, nil);
}
quotedc(argv: list of string, cl: string): string
{
s := "";
while(argv != nil){
arg := hd argv;
for(i := 0; i < len arg; i++){
c := arg[i];
if(c == ' ' || c == '\t' || c == '\n' || c == '\'' || in(c, cl))
break;
}
if(i < len arg || arg == nil){
s += "'" + arg[0:i];
for(; i < len arg; i++){
if (arg[i] == '\'')
s[len s] = '\'';
s[len s] = arg[i];
}
s[len s] = '\'';
}else
s += arg;
if(tl argv != nil)
s[len s] = ' ';
argv = tl argv;
}
return s;
}
unquoted(s: string): list of string
{
args: list of string;
word: string;
inquote := 0;
for(j := len s; j > 0;){
c := s[j-1];
if(c == ' ' || c == '\t' || c == '\n'){
j--;
continue;
}
for(i := j-1; i >= 0 && ((c = s[i]) != ' ' && c != '\t' && c != '\n' || inquote); i--){ # collect word
if(c == '\''){
word = s[i+1:j] + word;
j = i;
if(!inquote || i == 0 || s[i-1] != '\'')
inquote = !inquote;
else
i--;
}
}
args = (s[i+1:j]+word) :: args;
word = nil;
j = i;
}
# if quotes were unbalanced, balance them and try again.
if(inquote)
return unquoted(s + "'");
return args;
}
# Replace up to 'max' instances of 's' with 'with' in 'in'
replace(in, s, with: string, max: int): string {
if(max == 0 || s == "") {
# Nothing to replace
return in;
}
if(len in < 1) {
# No string given
return "";
}
n := 0;
# For each rune 'in' the original string
for(r0 := 0; r0 < len in ; r0++) {
# Try to build 's'
r1: int;
substring:
for(r1 = 0; r1 < len s; r1++) {
if(in[r0 + r1] == s[r1]) {
# Match so far
continue substring;
} else {
# No longer matches
break substring;
}
}
# We didn't break the loop, this is a match
# String will be [r0 , r0+len(s))
if(r1 >= len s) {
left, right: string;
# Left side
case r0 {
0 =>
# First rune, no left side
left = "";
* =>
left = in[:r0];
}
# Right side
redge := r0 + len s;
if(redge == len in - 1)
# Last rune
right = "";
else
right = in[redge:];
# Insert
in = left + with + right;
# Skip forward to end of replacement string
r0 = r0 + (len with - 1);
# Tick counts
n++;
if(n == max && max > 0) {
# We hit max and care about the number of replacements
return in;
}
}
}
return in;
}
# Returns >0 if s∈in and ≤0 if s∋in
contains(in, s: string): int {
if(in == "" || s == "") {
# Can't do anything
return 1;
}
# For each rune 'in' the original string
for(r0 := 0; r0 < len in ; r0++) {
# Try to build 's'
r1: int;
substring:
for(r1 = 0; r1 < len s && r0 + r1 < len in; r1++) {
if(in[r0 + r1] == s[r1]) {
# Match so far
continue substring;
} else {
# No longer matches
break substring;
}
}
# We didn't break the loop, this is a match
# String will be [r0 , r0+len(s))
if(r1 >= len s)
return 1;
}
return 0;
}
# Return whitespace-delimited elements
fields(s: string): list of string {
sys := load Sys Sys->PATH;
out: list of string;
word := "";
for(i := 0; i < len s; i++) {
case s[i] {
' ' or ' ' or '\n' =>
if(word != ""){
out = append(word, out);
word = "";
}
* =>
word += sys->sprint("%c", s[i]);
}
}
if(word != ""){
out = append(word, out);
}
return out;
}