steel/core/option
steel/core/result
steel/identity
steel/hash
hash-try-get
Gets the key from the given map. Returns #false if the key does not exist.
(hash-try-get map key) -> (or any/c #false)
- map : hash?
- key : any/c
Examples
> (hash-try-get (hash 'a 10 'b 20) 'b) ;; => 20
> (hash-try-get (hash 'a 10 'b 20) 'does-not-exist) ;; => #false
hash-length
Returns the number of key value pairs in the map
(hash-length map) -> (and positive? int?)
- map : hash?
Examples
> (hash-length (hash 'a 10 'b 20)) ;; => 2
hash-ref
Gets the key from the given map. Raises an error if the key does not exist. hash-get is an alias for this.
(hash-ref map key) -> any/c
- map : hash?
- key : any/c
Examples
> (hash-get (hash 'a 10 'b 20) 'b) ;; => 20
hash-contains?
Checks whether the given map contains the given key. Key must be hashable.
(hash-contains? map key) -> bool?
- map : hash?
- key : hashable?
Example
> (hash-contains? (hash 'a 10 'b 20) 'a) ;; => #true
> (hash-contains? (hash 'a 10 'b 20) 'not-there) ;; => #false
hash-insert
Returns a new hashmap with the additional key value pair added. Performs a functional update, so the old hash map is still accessible.
(hash-insert map key val) -> hash?
- map : hash?
- key : any/c
- val : any/c
Examples
> (hash-insert (hash 'a 10 'b 20) 'c 30)
=> #<hashmap {
'a: 10,
'b: 20,
'c: 30
}>
steel/random
steel/io
steel/equality
steel/ord
steel/json
steel/sets
steel/time
steel/time
steel/time
Contains direct wrappers around the Rust std::time::Instant and std::time::Duration modules.
For example, to measure the time something takes:
(define t (instant/now))
(displayln "Hello world")
(displayln (instant/elapsed t))
steel/vectors
steel/ports
read-port-to-string
Takes a port and reads the entire content into a string
(read-port-to-string port) -> string?
- port : input-port?
output-port?
Checks if a given value is an output port
(output-port? any/c) -> bool?
Examples
> (define output (open-output-file "foo.txt"))
> (output-port? output) ;; => #true
open-input-file
Takes a filename path referring to an existing file and returns an input port. Raises an error
if the file does not exist
(open-input-file string?) -> input-port?
Examples
> (open-input-file "foo-bar.txt") ;; => #<port>
> (open-input-file "file-does-not-exist.txt")
error[E08]: Io
┌─ :1:2
│
1 │ (open-input-file "foo-bar.txt")
│ ^^^^^^^^^^^^^^^ No such file or directory (os error 2)
stdin
Gets the port handle to stdin
(stdin) -> input-port?
Examples
> (stdin) ;; => #<port>
input-port?
Checks if a given value is an input port
(input-port? any/c) -> bool?
Examples
> (input-port? (stdin)) ;; => #true
> (input-port? "foo") ;; => #false
open-output-file
Takes a filename path referring to a file to be created and returns an output port.
(open-output-file string?) -> output-port?
Examples
> (open-output-file "foo-bar.txt") ;; => #<port>
steel/strings
starts-with?
Checks if the input string starts with a prefix
(starts-with? input pattern) -> bool?
input : string? pattern: string?
Examples
> (starts-with? "foobar" "foo") ;; => #true
> (starts-with? "foobar" "bar") ;; => #false
split-whitespace
Returns a list of strings from the original string split on the whitespace
(split-whitespace string?) -> (listof string?)
Examples
(split-whitespace "apples bananas fruits veggies") ;; '("apples" "bananas" "fruits" "veggies")
trim-end
Returns a new string with the trailing whitespace removed.
(trim string?) -> string?
Examples
> (trim " foo ") ;; => " foo"
string->int
Converts a string into an int. Raises an error if the string cannot be converted to an integer.
(string->int string?) -> int?
Examples
> (string->int "100") ;; => 10
> (string->int "not-an-int") ;; error
ends-with?
Checks if the input string ends with a given suffix
(ends-with? input pattern) -> bool?
input : string? pattern: string?
Examples
> (ends-with? "foobar" "foo") ;; => #false
> (ends-with? "foobar" "bar") ;; => #true
string-length
Get the length of the given string
(string-length string?) -> int?
Examples
> (string-length "apples") ;; => 6
trim-start
Returns a new string with the leading whitespace removed.
(trim string?) -> string?
Examples
> (trim " foo ") ;; => "foo "
string->upper
Creates a new uppercased version of the input string
(string->upper string?) -> string?
Examples
> (string->upper "lower") ;; => "LOWER"
trim
Returns a new string with the leading and trailing whitespace removed.
(trim string?) -> string?
Examples
> (trim " foo ") ;; => "foo"
string->list
Converts a string into a list of characters.
(string->list string?) -> (listof char?)
Examples
> (string->list "hello") ;; => '(#\h #\e #\l #\l #\o)
string->symbol
Converts a string into a symbol.
(string->symbol string?) -> symbol?
Examples
> (string->symbol "FooBar") ;; => 'FooBar
int->string
Converts an integer into a string.
(int->string int?) -> string?
Examples
> (int->string 10) ;; => "10"
string-append
Concatenates all of the given strings into one
(string-append strs...) -> string?
- strs ... : string?
Examples
> (string-append) ;; => ""
> (string-append "foo" "bar") ;; => "foobar"
### **string->lower**
Creates a new lowercased version of the input string
(string->lower string?) -> string?
#### Examples
```scheme
> (string->lower "sPonGeBoB tExT") ;; => "spongebob text"
to-string
Concatenatives all of the inputs to their string representation, separated by spaces.
(to-string xs ...)
- xs : any/c
Examples
> (to-string 10) ;; => "10"
> (to-string "hello" "world") ;; => "hello world"
steel/filesystem
steel/syntax
steel/transducers
steel/symbols
steel/strings/colors
steel/meta
steel/base
read-port-to-string
Takes a port and reads the entire content into a string
(read-port-to-string port) -> string?
- port : input-port?
hash-contains?
Checks whether the given map contains the given key. Key must be hashable.
(hash-contains? map key) -> bool?
- map : hash?
- key : hashable?
Example
> (hash-contains? (hash 'a 10 'b 20) 'a) ;; => #true
> (hash-contains? (hash 'a 10 'b 20) 'not-there) ;; => #false
list-ref
Returns the value located at the given index. Will raise an error if you try to index out of bounds.
Note: Runs in time proportional to the length of the list, however lists in Steel are implemented in such a fashion that the time complexity is O(n/64). Meaning, for small lists this can be constant.
(list-ref lst index) -> list?
- lst : list?
- index : (and/c int? positive?)
Examples
> (list-ref (list 1 2 3 4) 2) ;; => 3
> (list-ref (range 0 100) 42) ;; => 42"
> (list-ref (list 1 2 3 4) 10)
error[E11]: Generic
┌─ :1:2
│
1 │ (list-ref (list 1 2 3 4) 10)
│ ^^^^^^^^ out of bounds index in list-ref - list length: 4, index: 10
second
Get the second element of the list. Raises an error if the list does not have an element in the second position.
(second l) -> any/c
- l : list?
Examples
> (second '(1 2 3)) ;; => 2
> (second '())
error[E11]: Generic
┌─ :1:2
│
1 │ (second '())
│ ^^^^^^ second: index out of bounds - list did not have an element in the second position: []
### **to-string**
Concatenatives all of the inputs to their string representation, separated by spaces.
(to-string xs ...)
* xs : any/c
#### Examples
```scheme
> (to-string 10) ;; => "10"
> (to-string "hello" "world") ;; => "hello world"
output-port?
Checks if a given value is an output port
(output-port? any/c) -> bool?
Examples
> (define output (open-output-file "foo.txt"))
> (output-port? output) ;; => #true
open-output-file
Takes a filename path referring to a file to be created and returns an output port.
(open-output-file string?) -> output-port?
Examples
> (open-output-file "foo-bar.txt") ;; => #<port>
range
Returns a newly allocated list of the elements in the range (n, m]
(range n m) -> (listof int?)
- n : int?
- m : int?
> (range 0 10) ;; => '(0 1 2 3 4 5 6 7 8 9)
string-length
Get the length of the given string
(string-length string?) -> int?
Examples
> (string-length "apples") ;; => 6
car
Returns the first element of the list l.
(car l) -> any/c
- l : list?
Examples
> (car '(1 2)) ;; => 1
> (car (cons 2 3)) ;; => 2
hash-ref
Gets the key from the given map. Raises an error if the key does not exist. hash-get is an alias for this.
(hash-ref map key) -> any/c
- map : hash?
- key : any/c
Examples
> (hash-get (hash 'a 10 'b 20) 'b) ;; => 20
first
Returns the first element of the list l.
(first l) -> any/c
- l : list?
Examples
> (first '(1 2)) ;; => 1
> (first (cons 2 3)) ;; => 2
split-whitespace
Returns a list of strings from the original string split on the whitespace
(split-whitespace string?) -> (listof string?)
Examples
(split-whitespace "apples bananas fruits veggies") ;; '("apples" "bananas" "fruits" "veggies")
list
Returns a newly allocated list containing the vs as its elements.
(list v ...) -> list?
- v : any/c
Examples
> (list 1 2 3 4 5) ;; => '(1 2 3 4 5)
> (list (list 1 2) (list 3 4)) ;; => '((1 2) (3 4))
hash-try-get
Gets the key from the given map. Returns #false if the key does not exist.
(hash-try-get map key) -> (or any/c #false)
- map : hash?
- key : any/c
Examples
> (hash-try-get (hash 'a 10 'b 20) 'b) ;; => 20
> (hash-try-get (hash 'a 10 'b 20) 'does-not-exist) ;; => #false
pair?
Checks if the given value can be treated as a pair. Note - there are no improper lists in steel, so any list with at least one element is considered a pair.
(pair? any/c) -> bool?
Examples
> (pair? '(10 20)) ;; => #true
> (pair? '(10)) ;; => #true
> (pair? '()) ;; => #false
steel/lists
steel/lists
Lists in Steel have an interface that matches those of classic schemes or lisps. At face value, they appear to be implemented as cons cells - however, under the hood they are actually implemented as unrolled linked lists.
This means that for most practical purposes, interaction with lists is the same. That being said, there are no improper lists, meaning, pairs are actually just lists of two elements.
Indexing into a list also takes O(n/64) - which means you'll get constant time indexing on small lists.
(list 10 20 30 40) ;; => '(10 20 30 40)
third
Get the third element of the list. Raises an error if the list does not have an element in the third position.
(third l) -> any/c
- l : list?
Examples
> (third '(1 2 3)) ;; => 3
> (third '())
error[E11]: Generic
┌─ :1:2
│
1 │ (third '())
│ ^^^^^^ third: index out of bounds - list did not have an element in the second position: []
hash-length
Returns the number of key value pairs in the map
(hash-length map) -> (and positive? int?)
- map : hash?
Examples
> (hash-length (hash 'a 10 'b 20)) ;; => 2
string->upper
Creates a new uppercased version of the input string
(string->upper string?) -> string?
Examples
> (string->upper "lower") ;; => "LOWER"
trim
Returns a new string with the leading and trailing whitespace removed.
(trim string?) -> string?
Examples
> (trim " foo ") ;; => "foo"
starts-with?
Checks if the input string starts with a prefix
(starts-with? input pattern) -> bool?
input : string? pattern: string?
Examples
> (starts-with? "foobar" "foo") ;; => #true
> (starts-with? "foobar" "bar") ;; => #false
open-input-file
Takes a filename path referring to an existing file and returns an input port. Raises an error
if the file does not exist
(open-input-file string?) -> input-port?
Examples
> (open-input-file "foo-bar.txt") ;; => #<port>
> (open-input-file "file-does-not-exist.txt")
error[E08]: Io
┌─ :1:2
│
1 │ (open-input-file "foo-bar.txt")
│ ^^^^^^^^^^^^^^^ No such file or directory (os error 2)
input-port?
Checks if a given value is an input port
(input-port? any/c) -> bool?
Examples
> (input-port? (stdin)) ;; => #true
> (input-port? "foo") ;; => #false
ends-with?
Checks if the input string ends with a given suffix
(ends-with? input pattern) -> bool?
input : string? pattern: string?
Examples
> (ends-with? "foobar" "foo") ;; => #false
> (ends-with? "foobar" "bar") ;; => #true
string-append
Concatenates all of the given strings into one
(string-append strs...) -> string?
- strs ... : string?
Examples
> (string-append) ;; => ""
> (string-append "foo" "bar") ;; => "foobar"
### **steel/time**
#### steel/time
Contains direct wrappers around the Rust `std::time::Instant` and `std::time::Duration` modules.
For example, to measure the time something takes:
```scheme
(define t (instant/now))
(displayln "Hello world")
(displayln (instant/elapsed t))
trim-end
Returns a new string with the trailing whitespace removed.
(trim string?) -> string?
Examples
> (trim " foo ") ;; => " foo"
string->list
Converts a string into a list of characters.
(string->list string?) -> (listof char?)
Examples
> (string->list "hello") ;; => '(#\h #\e #\l #\l #\o)
empty?
Checks if the list is empty
(empty? lst) -> bool?
- lst: list?
Examples
> (empty? (list 1 2 3 4 5)) ;; => #false
> (empty? '()) ;; => #true
int->string
Converts an integer into a string.
(int->string int?) -> string?
Examples
> (int->string 10) ;; => "10"
trim-start
Returns a new string with the leading whitespace removed.
(trim string?) -> string?
Examples
> (trim " foo ") ;; => "foo "
stdin
Gets the port handle to stdin
(stdin) -> input-port?
Examples
> (stdin) ;; => #<port>
hash-insert
Returns a new hashmap with the additional key value pair added. Performs a functional update, so the old hash map is still accessible.
(hash-insert map key val) -> hash?
- map : hash?
- key : any/c
- val : any/c
Examples
> (hash-insert (hash 'a 10 'b 20) 'c 30)
=> #<hashmap {
'a: 10,
'b: 20,
'c: 30
}>
string->lower
Creates a new lowercased version of the input string
(string->lower string?) -> string?
Examples
> (string->lower "sPonGeBoB tExT") ;; => "spongebob text"
string->int
Converts a string into an int. Raises an error if the string cannot be converted to an integer.
(string->int string?) -> int?
Examples
> (string->int "100") ;; => 10
> (string->int "not-an-int") ;; error
string->symbol
Converts a string into a symbol.
(string->symbol string?) -> symbol?
Examples
> (string->symbol "FooBar") ;; => 'FooBar
steel/process
steel/numbers
steel/streams
steel/constants
steel/threads
steel/lists
steel/lists
steel/lists
Lists in Steel have an interface that matches those of classic schemes or lisps. At face value, they appear to be implemented as cons cells - however, under the hood they are actually implemented as unrolled linked lists.
This means that for most practical purposes, interaction with lists is the same. That being said, there are no improper lists, meaning, pairs are actually just lists of two elements.
Indexing into a list also takes O(n/64) - which means you'll get constant time indexing on small lists.
(list 10 20 30 40) ;; => '(10 20 30 40)
pair?
Checks if the given value can be treated as a pair. Note - there are no improper lists in steel, so any list with at least one element is considered a pair.
(pair? any/c) -> bool?
Examples
> (pair? '(10 20)) ;; => #true
> (pair? '(10)) ;; => #true
> (pair? '()) ;; => #false
car
Returns the first element of the list l.
(car l) -> any/c
- l : list?
Examples
> (car '(1 2)) ;; => 1
> (car (cons 2 3)) ;; => 2
third
Get the third element of the list. Raises an error if the list does not have an element in the third position.
(third l) -> any/c
- l : list?
Examples
> (third '(1 2 3)) ;; => 3
> (third '())
error[E11]: Generic
┌─ :1:2
│
1 │ (third '())
│ ^^^^^^ third: index out of bounds - list did not have an element in the second position: []
empty?
Checks if the list is empty
(empty? lst) -> bool?
- lst: list?
Examples
> (empty? (list 1 2 3 4 5)) ;; => #false
> (empty? '()) ;; => #true
range
Returns a newly allocated list of the elements in the range (n, m]
(range n m) -> (listof int?)
- n : int?
- m : int?
> (range 0 10) ;; => '(0 1 2 3 4 5 6 7 8 9)
first
Returns the first element of the list l.
(first l) -> any/c
- l : list?
Examples
> (first '(1 2)) ;; => 1
> (first (cons 2 3)) ;; => 2
list
Returns a newly allocated list containing the vs as its elements.
(list v ...) -> list?
- v : any/c
Examples
> (list 1 2 3 4 5) ;; => '(1 2 3 4 5)
> (list (list 1 2) (list 3 4)) ;; => '((1 2) (3 4))
second
Get the second element of the list. Raises an error if the list does not have an element in the second position.
(second l) -> any/c
- l : list?
Examples
> (second '(1 2 3)) ;; => 2
> (second '())
error[E11]: Generic
┌─ :1:2
│
1 │ (second '())
│ ^^^^^^ second: index out of bounds - list did not have an element in the second position: []
### **list-ref**
Returns the value located at the given index. Will raise an error if you try to index out of bounds.
Note: Runs in time proportional to the length of the list, however lists in Steel are implemented in such a fashion that the
time complexity is O(n/64). Meaning, for small lists this can be constant.
(list-ref lst index) -> list?
* lst : list?
* index : (and/c int? positive?)
#### Examples
```scheme
> (list-ref (list 1 2 3 4) 2) ;; => 3
> (list-ref (range 0 100) 42) ;; => 42"
> (list-ref (list 1 2 3 4) 10)
error[E11]: Generic
┌─ :1:2
│
1 │ (list-ref (list 1 2 3 4) 10)
│ ^^^^^^^^ out of bounds index in list-ref - list length: 4, index: 10