update sugar/string & docs

scribblings/string.scrbl

@@ -0,0 +1,53 @@
+#lang scribble/manual
+
+@(require scribble/eval (for-label racket sugar))
+
+@(define my-eval (make-base-eval))
+@(my-eval `(require sugar))
+
+@title{String}
+@defmodule[sugar/string]
+
+
+@defproc[
+(starts-with?
+[str stringish?]
+[starter stringish?])
+boolean?]
+Return @racket[#t] if @racket[_str] starts with @racket[_starter], otherwise @racket[#f].
+
+@examples[#:eval my-eval
+(starts-with? "foobar" "foo")
+(starts-with? "foobar" "foobar")
+(starts-with? "foobar" "zam")
+(starts-with? "foobar" "foobars")
+]
+
+
+@defproc[
+(ends-with?
+[str stringish?]
+[ender stringish?])
+boolean?]
+Return @racket[#t] if @racket[_str] ends with @racket[_ender], otherwise @racket[#f].
+
+@examples[#:eval my-eval
+(ends-with? "foobar" "foo")
+(ends-with? "foobar" "foobar")
+(ends-with? "foobar" "zam")
+(ends-with? "foobar" "foobars")
+]
+
+
+@defproc[
+(capitalized?
+[str stringish?])
+boolean?]
+Return @racket[#t] if @racket[_str] starts with a capital letter, otherwise @racket[#f].
+
+@examples[#:eval my-eval
+(capitalized? "Brennan")
+(capitalized? "Brennan stinks")
+(capitalized? "stinks")
+]
+

scribblings/sugar.scrbl

@@ -30,6 +30,8 @@ A collection of small functions to help make Racket code simpler & more readable
 
 @include-section["list.scrbl"]
 
+@include-section["string.scrbl"]
+
 @include-section["license.scrbl"]
 
 @index-section[]

string.rkt

@@ -1,13 +1,11 @@
 #lang racket/base
 (require "define.rkt" "coerce.rkt")
 
-
 (define+provide/contract (starts-with? str starter)
   (coerce/string? coerce/string? . -> . coerce/boolean?)
   (and (<= (string-length starter) (string-length str)) 
        (equal? (substring str 0 (string-length starter)) starter)))
 
-
 (define+provide/contract (ends-with? str ender)
   (coerce/string? coerce/string? . -> . coerce/boolean?)
   (and (<= (string-length ender) (string-length str)) 

tests.rkt

@@ -142,3 +142,15 @@
 (check-equal? (remove-ext* (->path ".foo.txt")) (->path ".foo.txt"))
 (check-not-equal? (remove-ext* foo.bar.txt-path) foo.bar-path) ; removes more than one ext
 (check-equal? (remove-ext* foo.bar.txt-path) foo-path)
+
+
+(check-true (starts-with? "foobar" "foo"))
+(check-true (starts-with? "foobar" "foobar"))
+(check-false (starts-with? "foobar" "zam"))
+(check-false (starts-with? "foobar" "foobars"))
+(check-true (ends-with? "foobar" "bar"))
+(check-false (ends-with? "foobar" "zam"))
+(check-true (ends-with? "foobar" "foobar"))
+(check-false (ends-with? "foobar" "foobars"))
+(check-true (capitalized? "Brennan"))
+(check-false (capitalized? "foobar"))