Strings

Module strings

import strings

Text operations that count characters, not bytes.

strings works on Like — a prelude.String or a single prelude.Char — so a one-character value can be passed anywhere text is expected.

Positions here are character positions. count returns the number of UTF-8 code points, which is not the same as len(): len("café") is 5 bytes, count("café") is 4 characters. Indexing a String directly gives bytes; charAt gives characters.

Dependencies

• ranges

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Contents

• Unions — Like
• Functions — charAt, concat, contains, count, firstIndexOf, from, hasPrefix, hasSuffix, isDigit, isEmpty, isLetter, isSpace, join, lastIndexOf, quote, range, repeat, replace, replaceFirst, replaceLast, slice, split, toLower, toUpper, trim, trimPrefix, trimSuffix, unquote

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Unions

Like

`strings/strings.zirr:6`

union Like {
	Char
	String
}

A single character or a sequence of characters.

Cases

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Functions

charAt

`strings/strings.zirr:19`

extern fn charAt(v: Like, index: Int) -> Char

Returns the character at index (0-based, counting characters, not bytes).

---

concat

`strings/strings.zirr:102`

extern fn concat(parts: [Like]) -> String

Concatenates every part into a single String, in order.

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contains

`strings/strings.zirr:55`

extern fn contains(v: Like, needle: Like) -> Bool

Returns whether needle occurs anywhere in v.

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count

`strings/strings.zirr:16`

extern fn count(v: Like) -> Int

Returns the number of characters (runes) in v. Unlike len(), which counts
bytes, this counts UTF-8 code points — len(“café”) is 5, count(“café”) is 4.

---

firstIndexOf

`strings/strings.zirr:67`

fn firstIndexOf(v: Like, needle: Like) -> Option

Returns the character index of needle’s first occurrence in v, or None if absent.

---

from

`strings/strings.zirr:12`

extern fn from(v: Like) -> String

Normalizes a Char or String to String.

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hasPrefix

`strings/strings.zirr:58`

extern fn hasPrefix(v: Like, prefix: Like) -> Bool

Returns whether v starts with prefix.

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hasSuffix

`strings/strings.zirr:61`

extern fn hasSuffix(v: Like, suffix: Like) -> Bool

Returns whether v ends with suffix.

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isDigit

`strings/strings.zirr:44`

extern fn isDigit(v: Like) -> Bool

Returns whether v is not empty and every character is a decimal digit.
Unicode-aware — isDigit(‘٣’) is true, isDigit(“”) is false.

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isEmpty

`strings/strings.zirr:38`

fn isEmpty(v: Like) -> Bool

Returns whether v has no characters.

---

isLetter

`strings/strings.zirr:48`

extern fn isLetter(v: Like) -> Bool

Returns whether v is not empty and every character is a letter.
Unicode-aware — isLetter(‘é’) is true, isLetter(“”) is false.

---

isSpace

`strings/strings.zirr:52`

extern fn isSpace(v: Like) -> Bool

Returns whether v is not empty and every character is whitespace.
Unicode-aware — a non-breaking space counts, isSpace(“”) is false.

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join

`strings/strings.zirr:99`

extern fn join(parts: [Like], separator: Like) -> String

Joins parts into a single String, with separator between each.

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lastIndexOf

`strings/strings.zirr:77`

fn lastIndexOf(v: Like, needle: Like) -> Option

Returns the character index of needle’s last occurrence in v, or None if absent.

---

quote

`strings/strings.zirr:127`

extern fn quote(v: Like) -> String

Returns v as a double-quoted string literal, escaping the characters that
need it, so the result reads back as Zirric source. A Char is quoted as a
String — quote(‘a’) is the same as quote(“a”).

---

range

`strings/strings.zirr:26`

fn range(v: Like, r: ranges.Like) -> String

Returns the characters of v selected by r.

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repeat

`strings/strings.zirr:105`

extern fn repeat(v: Like, n: Int) -> String

Returns v repeated n times.

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replace

`strings/strings.zirr:87`

extern fn replace(v: Like, target: Like, replacement: Like) -> String

Replaces every occurrence of target in v with replacement.

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replaceFirst

`strings/strings.zirr:90`

extern fn replaceFirst(v: Like, target: Like, replacement: Like) -> String

Replaces only the first occurrence of target in v with replacement.

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replaceLast

`strings/strings.zirr:93`

extern fn replaceLast(v: Like, target: Like, replacement: Like) -> String

Replaces only the last occurrence of target in v with replacement.

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slice

`strings/strings.zirr:23`

extern fn slice(v: Like, start: Int, end: Int) -> String

Returns the characters of v from start (inclusive) to end (exclusive),
counting characters, not bytes.

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split

`strings/strings.zirr:96`

extern fn split(v: Like, separator: Like) -> [String]

Splits v on every occurrence of separator.

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toLower

`strings/strings.zirr:113`

extern fn toLower(v: Like) -> Like

Returns v with every letter converted to lowercase. Preserves whether v
was a Char or a String — toLower(‘A’) is ‘a’, toLower(“A”) is “a”.

---

toUpper

`strings/strings.zirr:109`

extern fn toUpper(v: Like) -> Like

Returns v with every letter converted to uppercase. Preserves whether v
was a Char or a String — toUpper(‘a’) is ‘A’, toUpper(“a”) is “A”.

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trim

`strings/strings.zirr:116`

extern fn trim(v: Like) -> String

Returns v with leading and trailing whitespace removed.

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trimPrefix

`strings/strings.zirr:119`

extern fn trimPrefix(v: Like, prefix: Like) -> String

Returns v with a leading prefix removed, if present.

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trimSuffix

`strings/strings.zirr:122`

extern fn trimSuffix(v: Like, suffix: Like) -> String

Returns v with a trailing suffix removed, if present.

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unquote

`strings/strings.zirr:132`

extern fn unquote(v: Like) -> Result

Reads a quoted literal, returning Ok with the text it denotes and Err when v
is not one. Both literal forms are accepted, “"hi"” and “‘a’”, and quote
is inverted exactly.