String
Write a string
Section titled “Write a string”Given a file named “main.scm” with:
(import (scheme base))
(write-string "Hello, world!")When I successfully run stak main.scm
Then the stdout should contain exactly “Hello, world!”.
Create a string
Section titled “Create a string”Given a file named “main.scm” with:
(import (scheme base))
(write-string (string #\A #\B #\C))When I successfully run stak main.scm
Then the stdout should contain exactly “ABC”.
Convert a string to a list
Section titled “Convert a string to a list”Given a file named “main.scm” with:
(import (scheme base))
(for-each write-char (string->list "Hello, world!"))When I successfully run stak main.scm
Then the stdout should contain exactly “Hello, world!”.
Convert a list to a string
Section titled “Convert a list to a string”Given a file named “main.scm” with:
(import (scheme base))
(write-string (list->string (string->list "Hello, world!")))When I successfully run stak main.scm
Then the stdout should contain exactly “Hello, world!”.
Append strings
Section titled “Append strings”Given a file named “main.scm” with:
(import (scheme base))
(write-string (string-append <values>))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| values | output |
|---|---|
| “” | |
| “foo” | foo |
| “app” “le” | apple |
| “dis” “cov” “ery” | discovery |
Get a character in a string
Section titled “Get a character in a string”Given a file named “main.scm” with:
(import (scheme base))
(write-char (string-ref "<string>" <index>))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| string | index | output |
|---|---|---|
| a | 0 | a |
| ab | 0 | a |
| ab | 1 | b |
| abc | 0 | a |
| abc | 1 | b |
| abc | 2 | c |
Set a character in a string
Section titled “Set a character in a string”Given a file named “main.scm” with:
(import (scheme base))
(define xs (string-copy "aaa"))
(string-set! xs <index> #\<character>)
(write-u8 (if (equal? xs "<output>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| index | character | output |
|---|---|---|
| 0 | b | baa |
| 1 | b | aba |
| 2 | b | aab |
| 0 | a | aaa |
| index | character | output |
|---|---|---|
| 1 | 😄 | a😄a |
Get a length of a string
Section titled “Get a length of a string”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (= (string-length "<value>") <length>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| value | length |
|---|---|
| 0 | |
| a | 1 |
| aa | 2 |
| aaa | 3 |
Get a sub-string
Section titled “Get a sub-string”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (equal? (substring "<value>" <start> <end>) "<output>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| value | start | end | output |
|---|---|---|---|
| 0 | 0 | ||
| a | 0 | 0 | |
| a | 0 | 1 | a |
| ab | 0 | 0 | |
| ab | 0 | 1 | a |
| ab | 1 | 2 | b |
| ab | 0 | 2 | ab |
| abc | 0 | 0 | |
| abc | 0 | 1 | a |
| abc | 1 | 2 | b |
| abc | 2 | 3 | c |
| abc | 0 | 2 | ab |
| abc | 1 | 3 | bc |
| abc | 0 | 3 | abc |
Get a length of a string
Section titled “Get a length of a string”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (= (string-length "<value>") <length>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| value | length |
|---|---|
| 0 | |
| a | 1 |
| aa | 2 |
| aaa | 3 |
Copy a string in place
Section titled “Copy a string in place”Given a file named “main.scm” with:
(import (scheme base))
(define xs (string-copy "<to>"))
(string-copy! xs <at> "<from>" <start> <end>)
(write-u8 (if (equal? xs "<output>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| to | at | from | start | end | output |
|---|---|---|---|---|---|
| A | 0 | A | |||
| ABC | 0 | DEF | DEF | ||
| ABC | 1 | DE | ADE | ||
| ABC | 2 | D | ABD | ||
| ABCDE | 1 | FGH | AFGHE | ||
| ABCD | 1 | EFGH | 1 | AFGH | |
| ABCD | 1 | EFGH | 1 | 3 | AFGD |
Make a string
Section titled “Make a string”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (= (string-length (make-string <length>)) <length>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| length |
|---|
| 0 |
| 1 |
| 2 |
| 3 |
Make a string with a character
Section titled “Make a string with a character”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (equal? (make-string <length> <character>) "<output>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| length | character | output |
|---|---|---|
| 0 | #\A | |
| 1 | #\A | A |
| 2 | #\A | AA |
| 3 | #\A | AAA |
| 0 | #\B | |
| 1 | #\B | B |
| 2 | #\B | BB |
| 3 | #\B | BBB |
Iterate over a string
Section titled “Iterate over a string”Given a file named “main.scm” with:
(import (scheme base))
(string-for-each write-char "ABC")When I successfully run stak main.scm
Then the stdout should contain exactly “ABC”.
Map a function to a string
Section titled “Map a function to a string”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (equal? (string-map (lambda (x) (integer->char (+ 1 (char->integer x)))) "ABC") "BCD") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Check string equality
Section titled “Check string equality”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (string=? "<value>" "<value>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| value |
|---|
| a |
| ab |
| abc |
Check string inequality
Section titled “Check string inequality”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (string=? "<left>" "<right>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “B”.
Examples
Section titled “Examples”| left | right |
|---|---|
| a | |
| a | |
| a | b |
| a | ab |
| ab | a |
| aa | ab |
| aa | aaa |
| aaa | aa |
| aaa | aab |
| aab | aaa |
Compare strings
Section titled “Compare strings”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (<procedure> <strings>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| procedure | strings | output |
|---|---|---|
| string<? | “” “” | B |
| string<? | “” “a” | A |
| string<? | “a” “b” | A |
| string<? | “a” “b” “c” | A |
| string<? | “a” “aa” | A |
| string<? | “aa” “aa” | B |
| string<? | “aa” “ab” | A |
| string<? | “aa” “aaa” | A |
| string<? | “aaa” “aab” | A |
| string>? | “” “” | B |
| string>? | “a” “” | A |
| string>? | “a” “a” | B |
| string>? | “b” “a” | A |
| string>? | “c” “b” “a” | A |
| string>? | “aa” “a” | A |
| string>? | “aa” “aa” | B |
| string>? | “ab” “aa” | A |
| string>? | “ba” “aa” | A |
| string>? | “ba” “ab” | A |
| string<=? | “aa” “aa” | A |
| string<=? | “aa” “ab” | A |
| string<=? | “ab” “aa” | B |
| string<=? | “aa” “aa” “ab” | A |
| string>=? | “aa” “aa” | A |
| string>=? | “aa” “ab” | B |
| string>=? | “ab” “aa” | A |
| string>=? | “ab” “aa” “aa” | A |
Compare strings ignoring letter cases
Section titled “Compare strings ignoring letter cases”Given a file named “main.scm” with:
(import (scheme base) (scheme char))
(write-u8 (if (<procedure> <strings>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| procedure | strings | output |
|---|---|---|
| string-ci<? | “” “” | B |
| string-ci<? | “” “a” | A |
| string-ci<? | “a” “B” | A |
| string-ci<? | “a” “B” “C” | A |
| string-ci<? | “a” “AA” | A |
| string-ci<? | “AA” “aa” | B |
| string-ci<? | “aa” “AB” | A |
| string-ci<? | “aa” “AAA” | A |
| string-ci<? | “aaa” “AAB” | A |
| string-ci>? | “” “” | B |
| string-ci>? | “a” “” | A |
| string-ci>? | “A” “a” | B |
| string-ci>? | “B” “a” | A |
| string-ci>? | “C” “b” “a” | A |
| string-ci>? | “AA” “a” | A |
| string-ci>? | “aa” “AA” | B |
| string-ci>? | “AB” “aa” | A |
| string-ci>? | “BA” “aa” | A |
| string-ci>? | “BA” “ab” | A |
| string-ci<=? | “aa” “AA” | A |
| string-ci<=? | “aa” “AB” | A |
| string-ci<=? | “AB” “aa” | B |
| string-ci<=? | “aa” “AA” “AB” | A |
| string-ci>=? | “AA” “aa” | A |
| string-ci>=? | “aa” “AB” | B |
| string-ci>=? | “AB” “aa” | A |
| string-ci>=? | “AB” “aa” “aa” | A |
Convert a vector to a string
Section titled “Convert a vector to a string”Given a file named “main.scm” with:
(import (scheme base))
(write-string (vector->string #(<characters>) <range>))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| characters | range | output |
|---|---|---|
| #\A | A | |
| #\A #\B #\C | ABC | |
| #\A #\B #\C | 0 | ABC |
| #\A #\B #\C | 0 2 | AB |
| #\A #\B #\C | 1 3 | BC |
| #\A #\B #\C | 1 2 | B |
Convert a vector to a string
Section titled “Convert a vector to a string”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (equal? (string->vector "<string>" <range>) #(<characters>)) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| string | range | characters |
|---|---|---|
| A | #\A | |
| ABC | #\A #\B #\C | |
| ABC | 0 | #\A #\B #\C |
| ABC | 0 2 | #\A #\B |
| ABC | 1 3 | #\B #\C |
| ABC | 1 2 | #\B |
Convert a string to a byte vector
Section titled “Convert a string to a byte vector”Given a file named “main.scm” with:
(import (scheme base))
(define xs "<string>")
(write-u8 (if (equal? (utf8->string (string->utf8 xs)) xs) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| string |
|---|
| A |
| ABC |
| Aあ😄 |
Convert a string case
Section titled “Convert a string case”Given a file named “main.scm” with:
(import (scheme base) (scheme char))
(write-u8 (if (equal? (<predicate> "<input>") "<output>") 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| predicate | input | output |
|---|---|---|
| string-downcase | Ab | ab |
| string-foldcase | Ab | ab |
| string-upcase | Ab | AB |
Fill a string
Section titled “Fill a string”Given a file named “main.scm” with:
(import (scheme base))
(define xs (string-copy "<string>"))
(string-fill! xs <arguments>)
(write-string xs)When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| string | arguments | output |
|---|---|---|
| A | #\a | a |
| AB | #\a 0 | aa |
| AB | #\a 1 | Aa |
| ABC | #\a | aaa |
| ABCD | #\a 1 3 | AaaD |