lib/strings: Update docs and restructured code to improve readability of toInt and toIntBase10. (ed711738) · Commits · nix / nixpkgs

lib/strings.nix

+37 −21

Original line number	Diff line number	Diff line
		@@ -784,7 +784,7 @@ rec {
		false;

		/* Parse a string as an int. Does not support parsing of integers with preceding zero due to
		ambiguity between zero-padded and octal numbers.
		ambiguity between zero-padded and octal numbers. See toIntBase10.

		Type: string -> int

		@@ -805,25 +805,35 @@ rec {
		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
		# RegEx: Match any leading whitespace, then any digits, and finally match any trailing
		# whitespace.
		strippedInput = match "[[:space:]]([[:digit:]]+)[[:space:]]" str;

		# RegEx: Match any leading whitespace, then a leading '0', then at least one digit following
		# after, and finally match any trailing whitespace.
		isLeadingZero = match "[[:space:]]0[[: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 (elemAt strippedInput 0);
		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
		if isLeadingZero
		then throw "Ambiguity in interpretation of ${str} between octal and zero padded integer."
		else if strippedInput != null && isInt parsedInput
		then parsedInput
		else throw "Could not convert ${str} to int.";
		# 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.
		@@ -846,26 +856,32 @@ rec {
		toIntBase10 "3.14"
		=> error: floating point JSON numbers are not supported
		*/
		# Obviously, it is a bit hacky to use fromJSON this way.
		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 any leading whitespace, at least one '0', and any trailing whitespace.
		isZero = match "[[:space:]]0+[[:space:]]" str == [];
		# RegEx: Match at least one '0'.
		isZero = match "0+" (head strippedInput) == [];

		# Attempt to parse input
		parsedInput = fromJSON (elemAt strippedInput 0);
		parsedInput = fromJSON (head strippedInput);

		generalError = "toIntBase10: Could not convert ${escapeNixString str} to int.";

		in
		# Value is zero
		if isZero
		# 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
		else
		if strippedInput != null && isInt parsedInput
		then parsedInput
		else throw "Could not convert ${str} to int.";
		# 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.

lib/tests/misc.nix

+4 −0

Original line number	Diff line number	Diff line
		@@ -346,6 +346,8 @@ runTests {
		( 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; } )
		@@ -388,6 +390,8 @@ runTests {
		( 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; } )

lib/tests/modules.sh

+1 −1

Original line number	Diff line number	Diff line
		@@ -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 'Could not convert .* to int' 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

Admin message