Character
Check if a value is a character
Section titled “Check if a value is a character”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (char? <expression>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Examples
Section titled “Examples”| expression |
|---|
| #\A |
| #\newline |
| (integer->char 65) |
Check a character category
Section titled “Check a character category”Given a file named “main.scm” with:
(import (scheme base) (scheme char))
(write-u8 (if (<predicate> #\<value>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| predicate | value | output |
|---|---|---|
| char-alphabetic? | a | A |
| char-alphabetic? | A | A |
| char-alphabetic? | z | A |
| char-alphabetic? | Z | A |
| char-alphabetic? | 0 | B |
| char-numeric? | 0 | A |
| char-numeric? | 9 | A |
| char-numeric? | A | B |
| char-whitespace? | newline | A |
| char-whitespace? | return | A |
| char-whitespace? | space | A |
| char-whitespace? | tab | A |
| char-whitespace? | A | B |
Write a character
Section titled “Write a character”Given a file named “main.scm” with:
(import (scheme base))
(write-char #\A)When I successfully run stak main.scm
Then the stdout should contain exactly “A”.
Write a newline character
Section titled “Write a newline character”Given a file named “main.scm” with:
(import (scheme base))
(write-char #\A)(newline)(write-char #\B)When I successfully run stak main.scm
Then the stdout should contain exactly:
ABCompare characters
Section titled “Compare characters”Given a file named “main.scm” with:
(import (scheme base))
(write-u8 (if (<predicate> <characters>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| predicate | characters | output |
|---|---|---|
| char=? | #\A #\A | A |
| char=? | #\A #\B | B |
| char=? | #\A #\A #\A | A |
| char=? | #\A #\A #\B | B |
| char<? | #\A #\B | A |
| char<? | #\A #\A | B |
| char<? | #\B #\A | B |
| char<? | #\A #\B #\C | A |
| char<? | #\A #\B #\B | B |
| char<=? | #\A #\B | A |
| char<=? | #\A #\A | A |
| char<=? | #\B #\A | B |
| char<=? | #\A #\B #\C | A |
| char<=? | #\A #\B #\B | A |
Compare case-insensitive characters
Section titled “Compare case-insensitive characters”Given a file named “main.scm” with:
(import (scheme base) (scheme char))
(write-u8 (if (<predicate> <characters>) 65 66))When I successfully run stak main.scm
Then the stdout should contain exactly “<output>”.
Examples
Section titled “Examples”| predicate | characters | output |
|---|---|---|
| char-ci=? | #\A #\A | A |
| char-ci=? | #\a #\A | A |
| char-ci=? | #\A #\B | B |
Convert a character case
Section titled “Convert a character case”Given a file named “main.scm” with:
(import (scheme base) (scheme char))
(write-u8 (if (eqv? (<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 |
|---|---|---|
| char-downcase | #\A | #\a |
| char-downcase | #\a | #\a |
| char-upcase | #\a | #\A |
| char-upcase | #\A | #\A |