StdString¶
This module can be imported directly or as a part of the StdEnv module.
It provides useful definition for many critical interaction with strings.
Visit StdString on Cloogle for source code of this module.
Basic operations¶
These operators provide ways to manipulate strings.
Note that strings are simply arrays of characters, operations on arrays will work on strings also.
Concatenation¶
Signature
// CLEAN
(+++) infixr 5 :: {#Char} {#Char} -> {#Char}
(+++) strL strR => ...
Behavior
Joins the string strR to the end of strL.
Usage
// CLEAN
"123" +++ "45" // "12345"
"123" +++ "4" // "1234"
"123" +++ "" // "123"
Slicing¶
Signature
// CLEAN
(%) infixl 9 :: {#Char} (Int, Int) -> {#Char}
(%) strL (l, r) => ...
Behavior
Returns characters which are inclusive between the position l and r.
Usage
// CLEAN
"123" % ( 2, 4) // "3"
"123" % ( 0, 2) // "123"
"123" % ((-1), 0) // "12"
"123" % ((-2), 5) // "123"
Update¶
Signature
// CLEAN
(:=) infixl 9 :: {#Char} (Int, Char) -> {#Char}
(:=) str (idx, ch) => ...
Behavior
Overrides the character at the position idx with the given character ch.
Results in a run-time error when over-indexing or under-indexing.
$ Index too high in UPDATE string.
Usage
// CLEAN
"abcde" := ( 5, 'X') // run-time error
"abcde" := ( 2, 'C') // "abCde"
"abcde" := ( 0, 'A') // "Abcde"
"abcde" := ((-1), 'A') // run-time error
Relational operations¶
CLEAN performs pairwise to compare two strings. I recommend looking at the usage examples if the behavior is unclear.
Equal to¶
Signature
// CLEAN
(==) infix 4 :: {#Char} {#Char} -> Bool
(==) strL strR => ...
Behavior
Returns true if the two strings are equal. Otherwise, returns false.
Usage
// CLEAN
"" == "" // True
"12" == "12" // True
"12" == "1" // False
"1" == "12" // False
"12" == "13" // False
"13" == "12" // False
Not equal to¶
Signature
// CLEAN
(<>) infix 4 :: {#Char} {#Char} -> Bool
(<>) strL strR => ...
Behavior
Returns true if the two strings are not equal. Otherwise, returns false.
Usage
// CLEAN
"" <> "" // False
"12" <> "12" // False
"12" <> "1" // True
"1" <> "12" // True
"12" <> "13" // True
"13" <> "12" // True
Less than¶
Signature
// CLEAN
(<) infix 4 :: {#Char} {#Char} -> Bool
(<) strL strR => ...
Behavior
Returns true if the first string is lexically less than the second string. Otherwise, returns false.
Usage
// CLEAN
"" < "" // False
"12" < "12" // False
"12" < "1" // False
"1" < "12" // True
"12" < "13" // True
"13" < "12" // False
Less than or equal to¶
Signature
// CLEAN
(<=) infix 4 :: {#Char} {#Char} -> Bool
(<=) strL strR => ...
Behavior
Returns true if the first string is lexically less than or equal to the second string. Otherwise, returns false.
Usage
// CLEAN
"" <= "" // True
"12" <= "12" // True
"12" <= "1" // False
"1" <= "12" // True
"12" <= "13" // True
"13" <= "12" // False
Greater than¶
Signature
// CLEAN
(>) infix 4 :: {#Char} {#Char} -> Bool
(>) strL strR => ...
Behavior
Returns true if the first string is lexically greater than the second string. Otherwise, returns false.
Usage
// CLEAN
"" > "" // False
"12" > "12" // False
"12" > "1" // True
"1" > "12" // False
"12" > "13" // False
"13" > "12" // True
Greater than or equal to¶
Signature
// CLEAN
(>=) infix 4 :: {#Char} {#Char} -> Bool
(>=) strL strR => ...
Behavior
Returns true if the first string is lexically greater than or equal to the second string. Otherwise, returns false.
Usage
// CLEAN
"" >= "" // True
"12" >= "12" // True
"12" >= "1" // True
"1" >= "12" // False
"12" >= "13" // False
"13" >= "12" // True