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Use expect more in Str docs

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Richard Feldman 2022-11-14 11:35:49 -05:00
parent 3f8829e310
commit 477dda3cc6
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1 changed files with 13 additions and 23 deletions
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36
crates/compiler/builtins/roc/Str.roc
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@ -208,11 +208,9 @@ graphemes : Str -> List Str
## If the given string is empty, or if the given [U32] is not a valid
## code point, this will return [Bool.false].
##
## Str.startsWithScalar "鹏 means 'roc'" 40527 # true because "鹏" is Unicode scalar 40527
##
## Str.startsWithScalar "9" 9 # False because the Unicode scalar for "9" is 57, not 9
##
## Str.startsWithScalar "" 40527 # False
## expect Str.startsWithScalar "鹏 means 'roc'" 40527 # "鹏" is Unicode scalar 40527
## expect !Str.startsWithScalar "9" 9 # the Unicode scalar for "9" is 57, not 9
## expect !Str.startsWithScalar "" 40527
##
## **Performance Note:** This runs slightly faster than [Str.startsWith], so
## if you want to check whether a string begins with something that's representable
@ -243,30 +241,22 @@ toScalars : Str -> List U32
## (To split the string into a [List] of smaller [Str] values instead of [U8] values,
## see [Str.split].)
##
## Str.toUtf8 "Roc" # [82, 111, 99]
##
## Str.toUtf8 "鹏" # [233, 185, 143]
##
## Str.toUtf8 "சி" # [224, 174, 154, 224, 174, 191]
##
## Str.toUtf8 "🐦" # [240, 159, 144, 166]
## expect Str.toUtf8 "Roc" == [82, 111, 99]
## expect Str.toUtf8 "鹏" == [233, 185, 143]
## expect Str.toUtf8 "சி" == [224, 174, 154, 224, 174, 191]
## expect Str.toUtf8 "🐦" == [240, 159, 144, 166]
toUtf8 : Str -> List U8
## Converts a [List] of [U8] UTF-8 [code units](https://unicode.org/glossary/#code_unit) to a string.
##
## Returns `Err` if the given bytes are invalid UTF-8, and returns `Ok ""` when given `[]`.
##
## Str.fromUtf8 [82, 111, 99] # Ok "Roc"
##
## Str.fromUtf8 [233, 185, 143] # Ok "鹏"
##
## Str.fromUtf8 [224, 174, 154, 224, 174, 191] # Ok "சி"
##
## Str.fromUtf8 [240, 159, 144, 166] # Ok "🐦"
##
## Str.fromUtf8 [] # Ok ""
##
## Str.fromUtf8 [255] # Err
## expect Str.fromUtf8 [82, 111, 99] == Ok "Roc"
## expect Str.fromUtf8 [233, 185, 143] == Ok "鹏"
## expect Str.fromUtf8 [224, 174, 154, 224, 174, 191] == Ok "சி"
## expect Str.fromUtf8 [240, 159, 144, 166] == Ok "🐦"
## expect Str.fromUtf8 [] == Ok ""
## expect Str.fromUtf8 [255] |> Result.isErr
fromUtf8 : List U8 -> Result Str [BadUtf8 Utf8ByteProblem Nat]*
## Return a [List] of the [unicode scalar values](https://unicode.org/glossary/#unicode_scalar_value)