shithub: purgatorio

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ref: 84989770721391018dd6a247831cb79a43c1d86b
parent: 79c64a79a248c31733d4ec0ff9fe1a1e57a58f51
author: henesy <devnull@localhost>
date: Mon Dec 14 01:22:23 EST 2020

string(2): add contains()

--- a/appl/lib/string.b	Sun Dec 13 23:21:38 2020
+++ b/appl/lib/string.b	Mon Dec 14 01:22:23 2020
@@ -495,3 +495,39 @@
 	
 	return in;
 }
+
+# Returns >0 if s∈in and <=0 if s∋in
+contains(in, s: string): int {
+	if(s == "") {
+		# Of course
+		return 1;
+	}
+	if(len in < 1) {
+		# Can't have anything
+		return 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)
+			return 1;
+	}
+	
+	return 0;
+}
--- a/man/2/string	Sun Dec 13 23:21:38 2020
+++ b/man/2/string	Mon Dec 14 01:22:23 2020
@@ -14,6 +14,7 @@
 splitl:    fn(s, cl: string): (string, string);
 splitr:    fn(s, cl: string): (string, string);
 replace:   fn(in, s, with: string, max: int): string;
+contains:  fn(in, s: string): int;
 splitstrl: fn(s, t: string): (string, string);
 splitstrr: fn(s, t: string): (string, string);
 take:      fn(s, cl: string): string;
@@ -134,6 +135,14 @@
 the string
 .I in
 is returned unchanged. 
+
+.PP
+.B Contains
+returns >0 if
+.I s
+is contained within
+.I in
+and ≤0 otherwise. 
 
 .PP
 .B Take
--- a/module/string.m	Sun Dec 13 23:21:38 2020
+++ b/module/string.m	Mon Dec 14 01:22:23 2020
@@ -21,6 +21,7 @@
 	splitstrl:	fn(s, t: string): (string, string);
 	splitstrr:	fn(s, t: string): (string, string);
 	replace:	fn(in, s, with: string, max: int): string;
+	contains:	fn(in, s: string): int;
 
 	# is first arg a prefix of second?
 	prefix:		fn(pre, s: string): int;