1 Exception utilities
2 Number utilities
3 String utilities
4 Bytes utilities
5 Symbol utilities
6 List utilities
7 PLT 4x hash utilities
8 PLT 3x hash utilities
9 URL utilities
10 Contract utilities
11 File and path utilities
12 Parameter utilities
13 Syntax utilities
14 SRFI19 time utilities
15 Scribble utilities
16 Generators
17 Generators (short names)
18 Pipelines
19 Write-through cache
20 Yieldable procedures
21 Debugging tools
22 Profiling tools
23 Logging tools
On this page:
string+ false?
ensure-string
string-delimit
number+ false->string+ false
string+ false->number+ false
string+ false->symbol+ false
symbol+ false->string+ false
Version: 4.0.1.2

 

3 String utilities

 (require (planet untyped/unlib/string))

Useful string utilities. Compatible with PLT 4 languages.

(string+false? item)  boolean?

  item : any

Returns #t if item is a string and #f otherwise.

(ensure-string item)  any

  item : any

Converts bytes arguments to strings: passes all other arguments straight through.

(string-delimit

 

items

 

 

 

 

 

 

delimiter

 

 

 

 

 

 [

#:prefix prefix

 

 

 

 

 

 

#:suffix suffix])

 

 

string?

  items : (listof string?)

  delimiter : string?

  prefix : (U string? #f) = #f

  suffix : (U string? #f) = #f

Similar to string-join from SRFI 13, except that the optional #:prefix and #:suffix arguments can be provided to add a prefix or suffix string.

Examples:

  > (string-delimit '("1" "2" "3") ",")

  "1,2,3"

  > (string-delimit '("1" "2" "3") "," #:prefix "[")

  "[1,2,3"

  > (string-delimit '("1" "2" "3") "," #:suffix "]")

  "1,2,3]"

  > (string-delimit '("1" "2" "3") "," #:prefix "[" #:suffix "]")

  "[1,2,3]"

  > (string-delimit '("1" "2" "3") "," #:prefix #f #:suffix #f)

  "1,2,3"

(number+false->string+false num)  (U string? #f)

  num : (U number? #f)

A version of number->string that accepts and passes through #f.

(string+false->number+false str)  (U number? #f)

  str : (U string? #f)

A version of string->number that accepts and passes through #f.

(string+false->symbol+false str)  (U symbol? #f)

  str : (U string? #f)

A version of string->symbol that accepts and passes through #f.

(symbol+false->string+false sym)  (U string? #f)

  sym : (U symbol? #f)

A version of symbol->string that accepts and passes through #f.