Merge pull request #173949 from jacoblambda/fix-toInt-zero-padding

lib: add strings.toIntBase10 to parse zero-padded strings
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Robert Hensing 2022-10-24 13:22:42 +02:00 committed by GitHub
commit bc4ce318bf
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4 changed files with 160 additions and 8 deletions

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@ -103,7 +103,7 @@ let
getName getVersion
nameFromURL enableFeature enableFeatureAs withFeature
withFeatureAs fixedWidthString fixedWidthNumber isStorePath
toInt readPathsFromFile fileContents;
toInt toIntBase10 readPathsFromFile fileContents;
inherit (self.stringsWithDeps) textClosureList textClosureMap
noDepEntry fullDepEntry packEntry stringAfter;
inherit (self.customisation) overrideDerivation makeOverridable

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@ -783,24 +783,105 @@ rec {
else
false;
/* Parse a string as an int.
/* Parse a string as an int. Does not support parsing of integers with preceding zero due to
ambiguity between zero-padded and octal numbers. See toIntBase10.
Type: string -> int
Example:
toInt "1337"
=> 1337
toInt "-4"
=> -4
toInt " 123 "
=> 123
toInt "00024"
=> error: Ambiguity in interpretation of 00024 between octal and zero padded integer.
toInt "3.14"
=> error: floating point JSON numbers are not supported
*/
# Obviously, it is a bit hacky to use fromJSON this way.
toInt = str:
let may_be_int = fromJSON str; in
if isInt may_be_int
then may_be_int
else throw "Could not convert ${str} to int.";
let
# RegEx: Match any leading whitespace, then any digits, and finally match any trailing
# whitespace.
strippedInput = match "[[:space:]]*([[:digit:]]+)[[:space:]]*" str;
# RegEx: Match a leading '0' then one or more digits.
isLeadingZero = match "0[[:digit:]]+" (head strippedInput) == [];
# Attempt to parse input
parsedInput = fromJSON (head strippedInput);
generalError = "toInt: Could not convert ${escapeNixString str} to int.";
octalAmbigError = "toInt: Ambiguity in interpretation of ${escapeNixString str}"
+ " between octal and zero padded integer.";
in
# Error on presence of non digit characters.
if strippedInput == null
then throw generalError
# Error on presence of leading zero/octal ambiguity.
else if isLeadingZero
then throw octalAmbigError
# Error if parse function fails.
else if !isInt parsedInput
then throw generalError
# Return result.
else parsedInput;
/* Parse a string as a base 10 int. This supports parsing of zero-padded integers.
Type: string -> int
Example:
toIntBase10 "1337"
=> 1337
toIntBase10 "-4"
=> -4
toIntBase10 " 123 "
=> 123
toIntBase10 "00024"
=> 24
toIntBase10 "3.14"
=> error: floating point JSON numbers are not supported
*/
toIntBase10 = str:
let
# RegEx: Match any leading whitespace, then match any zero padding, capture any remaining
# digits after that, and finally match any trailing whitespace.
strippedInput = match "[[:space:]]*0*([[:digit:]]+)[[:space:]]*" str;
# RegEx: Match at least one '0'.
isZero = match "0+" (head strippedInput) == [];
# Attempt to parse input
parsedInput = fromJSON (head strippedInput);
generalError = "toIntBase10: Could not convert ${escapeNixString str} to int.";
in
# Error on presence of non digit characters.
if strippedInput == null
then throw generalError
# In the special case zero-padded zero (00000), return early.
else if isZero
then 0
# Error if parse function fails.
else if !isInt parsedInput
then throw generalError
# Return result.
else parsedInput;
/* Read a list of paths from `file`, relative to the `rootPath`.
Lines beginning with `#` are treated as comments and ignored.

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@ -327,6 +327,77 @@ runTests {
expected = "Hello\\x20World";
};
testToInt = testAllTrue [
# Naive
(123 == toInt "123")
(0 == toInt "0")
# Whitespace Padding
(123 == toInt " 123")
(123 == toInt "123 ")
(123 == toInt " 123 ")
(123 == toInt " 123 ")
(0 == toInt " 0")
(0 == toInt "0 ")
(0 == toInt " 0 ")
];
testToIntFails = testAllTrue [
( builtins.tryEval (toInt "") == { success = false; value = false; } )
( builtins.tryEval (toInt "123 123") == { success = false; value = false; } )
( builtins.tryEval (toInt "0 123") == { success = false; value = false; } )
( builtins.tryEval (toInt " 0d ") == { success = false; value = false; } )
( builtins.tryEval (toInt " 1d ") == { success = false; value = false; } )
( builtins.tryEval (toInt " d0 ") == { success = false; value = false; } )
( builtins.tryEval (toInt "00") == { success = false; value = false; } )
( builtins.tryEval (toInt "01") == { success = false; value = false; } )
( builtins.tryEval (toInt "002") == { success = false; value = false; } )
( builtins.tryEval (toInt " 002 ") == { success = false; value = false; } )
( builtins.tryEval (toInt " foo ") == { success = false; value = false; } )
( builtins.tryEval (toInt " foo 123 ") == { success = false; value = false; } )
( builtins.tryEval (toInt " foo123 ") == { success = false; value = false; } )
];
testToIntBase10 = testAllTrue [
# Naive
(123 == toIntBase10 "123")
(0 == toIntBase10 "0")
# Whitespace Padding
(123 == toIntBase10 " 123")
(123 == toIntBase10 "123 ")
(123 == toIntBase10 " 123 ")
(123 == toIntBase10 " 123 ")
(0 == toIntBase10 " 0")
(0 == toIntBase10 "0 ")
(0 == toIntBase10 " 0 ")
# Zero Padding
(123 == toIntBase10 "0123")
(123 == toIntBase10 "0000123")
(0 == toIntBase10 "000000")
# Whitespace and Zero Padding
(123 == toIntBase10 " 0123")
(123 == toIntBase10 "0123 ")
(123 == toIntBase10 " 0123 ")
(123 == toIntBase10 " 0000123")
(123 == toIntBase10 "0000123 ")
(123 == toIntBase10 " 0000123 ")
(0 == toIntBase10 " 000000")
(0 == toIntBase10 "000000 ")
(0 == toIntBase10 " 000000 ")
];
testToIntBase10Fails = testAllTrue [
( builtins.tryEval (toIntBase10 "") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 "123 123") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 "0 123") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " 0d ") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " 1d ") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " d0 ") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " foo ") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " foo 123 ") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " foo 00123 ") == { success = false; value = false; } )
( builtins.tryEval (toIntBase10 " foo00123 ") == { success = false; value = false; } )
];
# LISTS
testFilter = {

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@ -162,7 +162,7 @@ checkConfigError 'A definition for option .* is not.*string or signed integer co
# Check coerced value with unsound coercion
checkConfigOutput '^12$' config.value ./declare-coerced-value-unsound.nix
checkConfigError 'A definition for option .* is not of type .*. Definition values:\n\s*- In .*: "1000"' config.value ./declare-coerced-value-unsound.nix ./define-value-string-bigint.nix
checkConfigError 'json.exception.parse_error' config.value ./declare-coerced-value-unsound.nix ./define-value-string-arbitrary.nix
checkConfigError 'toInt: Could not convert .* to int' config.value ./declare-coerced-value-unsound.nix ./define-value-string-arbitrary.nix
# Check mkAliasOptionModule.
checkConfigOutput '^true$' config.enable ./alias-with-priority.nix