lib: add limit support to split() and replace()

Extend the split() and replace() functions to accept an additional optional
`limit` argument which limits the amount of split operations / substitutions
performed by these functions.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

2 files changed, 50 insertions, 0 deletions

diff --git a/tests/custom/03_stdlib/18_split b/tests/custom/03_stdlib/18_split
index 5ee35a2..20d5c8d 100644
--- a/tests/custom/03_stdlib/18_split
+++ b/tests/custom/03_stdlib/18_split
@@ -43,6 +43,18 @@ argument is neither a string nor a regular expression.
 
 		// subject and split strings handle embedded \0
 		split("foo=1\0bar=2\0baz=3", "\0"),
+
+		// supplying a limit only splits the string into that many parts
+		split("foo=1=2=3", "=", 2),
+
+		// limit of one produces a result array conaining the entire string as sole item
+		split("foo=1=2=3", "=", 1),
+
+		// negative limit yields an empty result array
+		split("foo=1=2=3", "=", -1),
+
+		// zero limit yields an empty result array
+		split("foo=1=2=3", "=", 0),
 	]), "\n");
 %}
 -- End --
@@ -62,6 +74,10 @@ argument is neither a string nor a regular expression.
 [ "", "abc", "def", "" ]
 [ "", "foo", "bar", "" ]
 [ "foo=1", "bar=2", "baz=3" ]
+[ "foo", "1=2=3" ]
+[ "foo=1=2=3" ]
+[ ]
+[ ]
 -- End --
 
 
diff --git a/tests/custom/03_stdlib/33_replace b/tests/custom/03_stdlib/33_replace
index b662ae8..388959f 100644
--- a/tests/custom/03_stdlib/33_replace
+++ b/tests/custom/03_stdlib/33_replace
@@ -205,3 +205,37 @@ In [anonymous function](), line 2, byte 40:
 
 
 -- End --
+
+
+An optional limit parameter controls the maximum amount of replacements.
+
+-- Testcase --
+{%
+	printf("%.J\n", [
+		// negative limit performs no substitution
+		replace("aaaaa", "a", "x", -1),
+
+		// zero limit performs no substitution
+		replace("aaaaa", "a", "x", 0),
+
+		// positive limit
+		replace("aaaaa", "a", "x", 3),
+
+		// same rules apply to regex replaces:
+		replace("foo bar baz", /[ao]/g, "x", -1),
+		replace("foo bar baz", /[ao]/g, "x", 0),
+		replace("foo bar baz", /[ao]/g, "x", 3),
+	]);
+%}
+-- End --
+
+-- Expect stdout --
+[
+	"aaaaa",
+	"aaaaa",
+	"xxxaa",
+	"foo bar baz",
+	"foo bar baz",
+	"fxx bxr baz"
+]
+-- End --