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diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim new file mode 100644 index 000000000..2ca255fa0 --- /dev/null +++ b/lib/pure/parseutils.nim @@ -0,0 +1,1087 @@ +# +# +# Nim's Runtime Library +# (c) Copyright 2012 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +## This module contains helpers for parsing tokens, numbers, integers, floats, +## identifiers, etc. +## +## To unpack raw bytes look at the `streams <streams.html>`_ module. +## +## ```nim test +## let logs = @["2019-01-10: OK_", "2019-01-11: FAIL_", "2019-01: aaaa"] +## var outp: seq[string] +## +## for log in logs: +## var res: string +## if parseUntil(log, res, ':') == 10: # YYYY-MM-DD == 10 +## outp.add(res & " - " & captureBetween(log, ' ', '_')) +## doAssert outp == @["2019-01-10 - OK", "2019-01-11 - FAIL"] +## ``` +## +## ```nim test +## from std/strutils import Digits, parseInt +## +## let +## input1 = "2019 school start" +## input2 = "3 years back" +## startYear = input1[0 .. skipWhile(input1, Digits)-1] # 2019 +## yearsBack = input2[0 .. skipWhile(input2, Digits)-1] # 3 +## examYear = parseInt(startYear) + parseInt(yearsBack) +## doAssert "Examination is in " & $examYear == "Examination is in 2022" +## ``` +## +## **See also:** +## * `strutils module<strutils.html>`_ for combined and identical parsing proc's +## * `json module<json.html>`_ for a JSON parser +## * `parsecfg module<parsecfg.html>`_ for a configuration file parser +## * `parsecsv module<parsecsv.html>`_ for a simple CSV (comma separated value) parser +## * `parseopt module<parseopt.html>`_ for a command line parser +## * `parsexml module<parsexml.html>`_ for a XML / HTML parser +## * `other parsers<lib.html#pure-libraries-parsers>`_ for other parsers + +{.push debugger: off.} # the user does not want to trace a part + # of the standard library! + +include "system/inclrtl" + +template toOa(s: string): openArray[char] = openArray[char](s) + +const + Whitespace = {' ', '\t', '\v', '\r', '\l', '\f'} + IdentChars = {'a'..'z', 'A'..'Z', '0'..'9', '_'} + IdentStartChars = {'a'..'z', 'A'..'Z', '_'} + ## copied from strutils + +proc toLower(c: char): char {.inline.} = + result = if c in {'A'..'Z'}: chr(ord(c)-ord('A')+ord('a')) else: c + +proc parseBin*[T: SomeInteger](s: openArray[char], number: var T, maxLen = 0): int {.noSideEffect.} = + ## Parses a binary number and stores its value in ``number``. + ## + ## Returns the number of the parsed characters or 0 in case of an error. + ## If error, the value of ``number`` is not changed. + ## + ## If ``maxLen == 0``, the parsing continues until the first non-bin character + ## or to the end of the string. Otherwise, no more than ``maxLen`` characters + ## are parsed starting from the ``start`` position. + ## + ## It does not check for overflow. If the value represented by the string is + ## too big to fit into ``number``, only the value of last fitting characters + ## will be stored in ``number`` without producing an error. + runnableExamples: + var num: int + doAssert parseBin("0100_1110_0110_1001_1110_1101", num) == 29 + doAssert num == 5138925 + doAssert parseBin("3", num) == 0 + var num8: int8 + doAssert parseBin("0b_0100_1110_0110_1001_1110_1101", num8) == 32 + doAssert num8 == 0b1110_1101'i8 + doAssert parseBin("0b_0100_1110_0110_1001_1110_1101", num8, 3, 9) == 9 + doAssert num8 == 0b0100_1110'i8 + var num8u: uint8 + doAssert parseBin("0b_0100_1110_0110_1001_1110_1101", num8u) == 32 + doAssert num8u == 237 + var num64: int64 + doAssert parseBin("0100111001101001111011010100111001101001", num64) == 40 + doAssert num64 == 336784608873 + var i = 0 + var output = T(0) + var foundDigit = false + let last = min(s.len, if maxLen == 0: s.len else: i + maxLen) + if i + 1 < last and s[i] == '0' and (s[i+1] in {'b', 'B'}): inc(i, 2) + while i < last: + case s[i] + of '_': discard + of '0'..'1': + output = output shl 1 or T(ord(s[i]) - ord('0')) + foundDigit = true + else: break + inc(i) + if foundDigit: + number = output + result = i + +proc parseOct*[T: SomeInteger](s: openArray[char], number: var T, maxLen = 0): int {.noSideEffect.} = + ## Parses an octal number and stores its value in ``number``. + ## + ## Returns the number of the parsed characters or 0 in case of an error. + ## If error, the value of ``number`` is not changed. + ## + ## If ``maxLen == 0``, the parsing continues until the first non-oct character + ## or to the end of the string. Otherwise, no more than ``maxLen`` characters + ## are parsed starting from the ``start`` position. + ## + ## It does not check for overflow. If the value represented by the string is + ## too big to fit into ``number``, only the value of last fitting characters + ## will be stored in ``number`` without producing an error. + runnableExamples: + var num: int + doAssert parseOct("0o23464755", num) == 10 + doAssert num == 5138925 + doAssert parseOct("8", num) == 0 + var num8: int8 + doAssert parseOct("0o_1464_755", num8) == 11 + doAssert num8 == -19 + doAssert parseOct("0o_1464_755", num8, 3, 3) == 3 + doAssert num8 == 102 + var num8u: uint8 + doAssert parseOct("1464755", num8u) == 7 + doAssert num8u == 237 + var num64: int64 + doAssert parseOct("2346475523464755", num64) == 16 + doAssert num64 == 86216859871725 + var i = 0 + var output = T(0) + var foundDigit = false + let last = min(s.len, if maxLen == 0: s.len else: i + maxLen) + if i + 1 < last and s[i] == '0' and (s[i+1] in {'o', 'O'}): inc(i, 2) + while i < last: + case s[i] + of '_': discard + of '0'..'7': + output = output shl 3 or T(ord(s[i]) - ord('0')) + foundDigit = true + else: break + inc(i) + if foundDigit: + number = output + result = i + +proc parseHex*[T: SomeInteger](s: openArray[char], number: var T, maxLen = 0): int {.noSideEffect.} = + ## Parses a hexadecimal number and stores its value in ``number``. + ## + ## Returns the number of the parsed characters or 0 in case of an error. + ## If error, the value of ``number`` is not changed. + ## + ## If ``maxLen == 0``, the parsing continues until the first non-hex character + ## or to the end of the string. Otherwise, no more than ``maxLen`` characters + ## are parsed starting from the ``start`` position. + ## + ## It does not check for overflow. If the value represented by the string is + ## too big to fit into ``number``, only the value of last fitting characters + ## will be stored in ``number`` without producing an error. + runnableExamples: + var num: int + doAssert parseHex("4E_69_ED", num) == 8 + doAssert num == 5138925 + doAssert parseHex("X", num) == 0 + doAssert parseHex("#ABC", num) == 4 + var num8: int8 + doAssert parseHex("0x_4E_69_ED", num8) == 11 + doAssert num8 == 0xED'i8 + doAssert parseHex("0x_4E_69_ED", num8, 3, 2) == 2 + doAssert num8 == 0x4E'i8 + var num8u: uint8 + doAssert parseHex("0x_4E_69_ED", num8u) == 11 + doAssert num8u == 237 + var num64: int64 + doAssert parseHex("4E69ED4E69ED", num64) == 12 + doAssert num64 == 86216859871725 + var i = 0 + var output = T(0) + var foundDigit = false + let last = min(s.len, if maxLen == 0: s.len else: i + maxLen) + if i + 1 < last and s[i] == '0' and (s[i+1] in {'x', 'X'}): inc(i, 2) + elif i < last and s[i] == '#': inc(i) + while i < last: + case s[i] + of '_': discard + of '0'..'9': + output = output shl 4 or T(ord(s[i]) - ord('0')) + foundDigit = true + of 'a'..'f': + output = output shl 4 or T(ord(s[i]) - ord('a') + 10) + foundDigit = true + of 'A'..'F': + output = output shl 4 or T(ord(s[i]) - ord('A') + 10) + foundDigit = true + else: break + inc(i) + if foundDigit: + number = output + result = i + +proc parseIdent*(s: openArray[char], ident: var string): int = + ## Parses an identifier and stores it in ``ident``. Returns + ## the number of the parsed characters or 0 in case of an error. + ## If error, the value of `ident` is not changed. + runnableExamples: + var res: string + doAssert parseIdent("Hello World", res, 0) == 5 + doAssert res == "Hello" + doAssert parseIdent("Hello World", res, 1) == 4 + doAssert res == "ello" + doAssert parseIdent("Hello World", res, 6) == 5 + doAssert res == "World" + var i = 0 + if i < s.len and s[i] in IdentStartChars: + inc(i) + while i < s.len and s[i] in IdentChars: inc(i) + ident = substr(s.toOpenArray(0, i-1)) + result = i + +proc parseIdent*(s: openArray[char]): string = + ## Parses an identifier and returns it or an empty string in + ## case of an error. + runnableExamples: + doAssert parseIdent("Hello World", 0) == "Hello" + doAssert parseIdent("Hello World", 1) == "ello" + doAssert parseIdent("Hello World", 5) == "" + doAssert parseIdent("Hello World", 6) == "World" + result = "" + var i = 0 + if i < s.len and s[i] in IdentStartChars: + inc(i) + while i < s.len and s[i] in IdentChars: inc(i) + result = substr(s.toOpenArray(0, i - 1)) + +proc parseChar*(s: openArray[char], c: var char): int = + ## Parses a single character, stores it in `c` and returns 1. + ## In case of error (if start >= s.len) it returns 0 + ## and the value of `c` is unchanged. + runnableExamples: + var c: char + doAssert "nim".parseChar(c, 3) == 0 + doAssert c == '\0' + doAssert "nim".parseChar(c, 0) == 1 + doAssert c == 'n' + if s.len > 0: + c = s[0] + result = 1 + +proc skipWhitespace*(s: openArray[char]): int {.inline.} = + ## Skips the whitespace starting at ``s[start]``. Returns the number of + ## skipped characters. + runnableExamples: + doAssert skipWhitespace("Hello World", 0) == 0 + doAssert skipWhitespace(" Hello World", 0) == 1 + doAssert skipWhitespace("Hello World", 5) == 1 + doAssert skipWhitespace("Hello World", 5) == 2 + result = 0 + while result < s.len and s[result] in Whitespace: inc(result) + +proc skip*(s, token: openArray[char]): int {.inline.} = + ## Skips the `token` starting at ``s[start]``. Returns the length of `token` + ## or 0 if there was no `token` at ``s[start]``. + runnableExamples: + doAssert skip("2019-01-22", "2019", 0) == 4 + doAssert skip("2019-01-22", "19", 0) == 0 + doAssert skip("2019-01-22", "19", 2) == 2 + doAssert skip("CAPlow", "CAP", 0) == 3 + doAssert skip("CAPlow", "cap", 0) == 0 + result = 0 + while result < s.len and result < token.len and + s[result] == token[result]: + inc(result) + if result != token.len: result = 0 + +proc skipIgnoreCase*(s, token: openArray[char]): int = + ## Same as `skip` but case is ignored for token matching. + runnableExamples: + doAssert skipIgnoreCase("CAPlow", "CAP", 0) == 3 + doAssert skipIgnoreCase("CAPlow", "cap", 0) == 3 + result = 0 + while result < s.len and result < token.len and + toLower(s[result]) == toLower(token[result]): inc(result) + if result != token.len: result = 0 + +proc skipUntil*(s: openArray[char], until: set[char]): int {.inline.} = + ## Skips all characters until one char from the set `until` is found + ## or the end is reached. + ## Returns number of characters skipped. + runnableExamples: + doAssert skipUntil("Hello World", {'W', 'e'}, 0) == 1 + doAssert skipUntil("Hello World", {'W'}, 0) == 6 + doAssert skipUntil("Hello World", {'W', 'd'}, 0) == 6 + result = 0 + while result < s.len and s[result] notin until: inc(result) + +proc skipUntil*(s: openArray[char], until: char): int {.inline.} = + ## Skips all characters until the char `until` is found + ## or the end is reached. + ## Returns number of characters skipped. + runnableExamples: + doAssert skipUntil("Hello World", 'o', 0) == 4 + doAssert skipUntil("Hello World", 'o', 4) == 0 + doAssert skipUntil("Hello World", 'W', 0) == 6 + doAssert skipUntil("Hello World", 'w', 0) == 11 + result = 0 + while result < s.len and s[result] != until: inc(result) + +proc skipWhile*(s: openArray[char], toSkip: set[char]): int {.inline.} = + ## Skips all characters while one char from the set `toSkip` is found. + ## Returns number of characters skipped. + runnableExamples: + doAssert skipWhile("Hello World", {'H', 'e'}) == 2 + doAssert skipWhile("Hello World", {'e'}) == 0 + doAssert skipWhile("Hello World", {'W', 'o', 'r'}, 6) == 3 + result = 0 + while result < s.len and s[result] in toSkip: inc(result) + +proc fastSubstr(s: openArray[char]; token: var string; length: int) = + token.setLen length + for i in 0 ..< length: token[i] = s[i] + +proc parseUntil*(s: openArray[char], token: var string, until: set[char]): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of the characters notin `until`. + runnableExamples: + var myToken: string + doAssert parseUntil("Hello World", myToken, {'W', 'o', 'r'}) == 4 + doAssert myToken == "Hell" + doAssert parseUntil("Hello World", myToken, {'W', 'r'}) == 6 + doAssert myToken == "Hello " + doAssert parseUntil("Hello World", myToken, {'W', 'r'}, 3) == 3 + doAssert myToken == "lo " + var i = 0 + while i < s.len and s[i] notin until: inc(i) + result = i + fastSubstr(s, token, result) + #token = substr(s, start, i-1) + +proc parseUntil*(s: openArray[char], token: var string, until: char): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of any character that is not the `until` character. + runnableExamples: + var myToken: string + doAssert parseUntil("Hello World", myToken, 'W') == 6 + doAssert myToken == "Hello " + doAssert parseUntil("Hello World", myToken, 'o') == 4 + doAssert myToken == "Hell" + doAssert parseUntil("Hello World", myToken, 'o', 2) == 2 + doAssert myToken == "ll" + var i = 0 + while i < s.len and s[i] != until: inc(i) + result = i + fastSubstr(s, token, result) + #token = substr(s, start, i-1) + +proc parseUntil*(s: openArray[char], token: var string, until: string): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of any character that comes before the `until` token. + runnableExamples: + var myToken: string + doAssert parseUntil("Hello World", myToken, "Wor") == 6 + doAssert myToken == "Hello " + doAssert parseUntil("Hello World", myToken, "Wor", 2) == 4 + doAssert myToken == "llo " + when (NimMajor, NimMinor) <= (1, 0): + if until.len == 0: + token.setLen(0) + return 0 + var i = 0 + while i < s.len: + if until.len > 0 and s[i] == until[0]: + var u = 1 + while i+u < s.len and u < until.len and s[i+u] == until[u]: + inc u + if u >= until.len: break + inc(i) + result = i + fastSubstr(s, token, result) + #token = substr(s, start, i-1) + +proc parseWhile*(s: openArray[char], token: var string, validChars: set[char]): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of the characters in `validChars`. + runnableExamples: + var myToken: string + doAssert parseWhile("Hello World", myToken, {'W', 'o', 'r'}, 0) == 0 + doAssert myToken.len() == 0 + doAssert parseWhile("Hello World", myToken, {'W', 'o', 'r'}, 6) == 3 + doAssert myToken == "Wor" + var i = 0 + while i < s.len and s[i] in validChars: inc(i) + result = i + fastSubstr(s, token, result) + #token = substr(s, start, i-1) + +proc captureBetween*(s: openArray[char], first: char, second = '\0'): string = + ## Finds the first occurrence of ``first``, then returns everything from there + ## up to ``second`` (if ``second`` is '\0', then ``first`` is used). + runnableExamples: + doAssert captureBetween("Hello World", 'e') == "llo World" + doAssert captureBetween("Hello World", 'e', 'r') == "llo Wo" + doAssert captureBetween("Hello World".toOpenArray(6, "Hello World".high), 'l') == "d" + var i = skipUntil(s, first) + 1 + result = "" + discard parseUntil(s.toOpenArray(i, s.high), result, if second == '\0': first else: second) + +proc integerOutOfRangeError() {.noinline.} = + raise newException(ValueError, "Parsed integer outside of valid range") + +# See #6752 +when defined(js): + {.push overflowChecks: off.} + +proc rawParseInt(s: openArray[char], b: var BiggestInt): int = + var + sign: BiggestInt = -1 + i = 0 + if i < s.len: + if s[i] == '+': inc(i) + elif s[i] == '-': + inc(i) + sign = 1 + if i < s.len and s[i] in {'0'..'9'}: + b = 0 + while i < s.len and s[i] in {'0'..'9'}: + let c = ord(s[i]) - ord('0') + if b >= (low(BiggestInt) + c) div 10: + b = b * 10 - c + else: + integerOutOfRangeError() + inc(i) + while i < s.len and s[i] == '_': inc(i) # underscores are allowed and ignored + if sign == -1 and b == low(BiggestInt): + integerOutOfRangeError() + else: + b = b * sign + result = i + +when defined(js): + {.pop.} # overflowChecks: off + +proc parseBiggestInt*(s: openArray[char], number: var BiggestInt): int {. + rtl, extern: "npuParseBiggestInt", noSideEffect, raises: [ValueError].} = + ## Parses an integer and stores the value into `number`. + ## Result is the number of processed chars or 0 if there is no integer. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: BiggestInt + doAssert parseBiggestInt("9223372036854775807", res) == 19 + doAssert res == 9223372036854775807 + doAssert parseBiggestInt("-2024_05_09", res) == 11 + doAssert res == -20240509 + var res = BiggestInt(0) + # use 'res' for exception safety (don't write to 'number' in case of an + # overflow exception): + result = rawParseInt(s, res) + if result != 0: + number = res + +proc parseInt*(s: openArray[char], number: var int): int {. + rtl, extern: "npuParseInt", noSideEffect, raises: [ValueError].} = + ## Parses an integer and stores the value into `number`. + ## Result is the number of processed chars or 0 if there is no integer. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: int + doAssert parseInt("-2024_05_02", res) == 11 + doAssert res == -20240502 + var res = BiggestInt(0) + result = parseBiggestInt(s, res) + when sizeof(int) <= 4: + if res < low(int) or res > high(int): + integerOutOfRangeError() + if result != 0: + number = int(res) + +proc parseSaturatedNatural*(s: openArray[char], b: var int): int {. + raises: [].} = + ## Parses a natural number into ``b``. This cannot raise an overflow + ## error. ``high(int)`` is returned for an overflow. + ## The number of processed character is returned. + ## This is usually what you really want to use instead of `parseInt`:idx:. + runnableExamples: + var res = 0 + discard parseSaturatedNatural("848", res) + doAssert res == 848 + var i = 0 + if i < s.len and s[i] == '+': inc(i) + if i < s.len and s[i] in {'0'..'9'}: + b = 0 + while i < s.len and s[i] in {'0'..'9'}: + let c = ord(s[i]) - ord('0') + if b <= (high(int) - c) div 10: + b = b * 10 + c + else: + b = high(int) + inc(i) + while i < s.len and s[i] == '_': inc(i) # underscores are allowed and ignored + result = i + +proc rawParseUInt(s: openArray[char], b: var BiggestUInt): int = + var + res = 0.BiggestUInt + prev = 0.BiggestUInt + i = 0 + if i < s.len - 1 and s[i] == '-' and s[i + 1] in {'0'..'9'}: + integerOutOfRangeError() + if i < s.len and s[i] == '+': inc(i) # Allow + if i < s.len and s[i] in {'0'..'9'}: + b = 0 + while i < s.len and s[i] in {'0'..'9'}: + prev = res + res = res * 10 + (ord(s[i]) - ord('0')).BiggestUInt + if prev > res: + integerOutOfRangeError() + inc(i) + while i < s.len and s[i] == '_': inc(i) # underscores are allowed and ignored + b = res + result = i + +proc parseBiggestUInt*(s: openArray[char], number: var BiggestUInt): int {. + rtl, extern: "npuParseBiggestUInt", noSideEffect, raises: [ValueError].} = + ## Parses an unsigned integer and stores the value + ## into `number`. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: BiggestUInt + doAssert parseBiggestUInt("12", res, 0) == 2 + doAssert res == 12 + doAssert parseBiggestUInt("1111111111111111111", res, 0) == 19 + doAssert res == 1111111111111111111'u64 + var res = BiggestUInt(0) + # use 'res' for exception safety (don't write to 'number' in case of an + # overflow exception): + result = rawParseUInt(s, res) + if result != 0: + number = res + +proc parseUInt*(s: openArray[char], number: var uint): int {. + rtl, extern: "npuParseUInt", noSideEffect, raises: [ValueError].} = + ## Parses an unsigned integer and stores the value + ## into `number`. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: uint + doAssert parseUInt("3450", res) == 4 + doAssert res == 3450 + doAssert parseUInt("3450", res, 2) == 2 + doAssert res == 50 + var res = BiggestUInt(0) + result = parseBiggestUInt(s, res) + when sizeof(BiggestUInt) > sizeof(uint) and sizeof(uint) <= 4: + if res > 0xFFFF_FFFF'u64: + integerOutOfRangeError() + if result != 0: + number = uint(res) + +proc parseBiggestFloat*(s: openArray[char], number: var BiggestFloat): int {. + magic: "ParseBiggestFloat", importc: "nimParseBiggestFloat", noSideEffect.} + ## Parses a float and stores the value into `number`. + ## Result is the number of processed chars or 0 if a parsing error + ## occurred. + +proc parseFloat*(s: openArray[char], number: var float): int {. + rtl, extern: "npuParseFloat", noSideEffect.} = + ## Parses a float and stores the value into `number`. + ## Result is the number of processed chars or 0 if there occurred a parsing + ## error. + runnableExamples: + var res: float + doAssert parseFloat("32", res, 0) == 2 + doAssert res == 32.0 + doAssert parseFloat("32.57", res, 0) == 5 + doAssert res == 32.57 + doAssert parseFloat("32.57", res, 3) == 2 + doAssert res == 57.00 + var bf = BiggestFloat(0.0) + result = parseBiggestFloat(s, bf) + if result != 0: + number = bf + +func toLowerAscii(c: char): char = + if c in {'A'..'Z'}: char(uint8(c) xor 0b0010_0000'u8) else: c + +func parseSize*(s: openArray[char], size: var int64, alwaysBin=false): int = + ## Parse a size qualified by binary or metric units into `size`. This format + ## is often called "human readable". Result is the number of processed chars + ## or 0 on parse errors and size is rounded to the nearest integer. Trailing + ## garbage like "/s" in "1k/s" is allowed and detected by `result < s.len`. + ## + ## To simplify use, following non-rare wild conventions, and since fractional + ## data like milli-bytes is so rare, unit matching is case-insensitive but for + ## the 'i' distinguishing binary-metric from metric (which cannot be 'I'). + ## + ## An optional trailing 'B|b' is ignored but processed. I.e., you must still + ## know if units are bytes | bits or infer this fact via the case of s[^1] (if + ## users can even be relied upon to use 'B' for byte and 'b' for bit or have + ## that be s[^1]). + ## + ## If `alwaysBin==true` then scales are always binary-metric, but e.g. "KiB" + ## is still accepted for clarity. If the value would exceed the range of + ## `int64`, `size` saturates to `int64.high`. Supported metric prefix chars + ## include k, m, g, t, p, e, z, y (but z & y saturate unless the number is a + ## small fraction). + ## + ## **See also:** + ## * https://en.wikipedia.org/wiki/Binary_prefix + ## * `formatSize module<strutils.html>`_ for formatting + runnableExamples: + var res: int64 # caller must still know if 'b' refers to bytes|bits + doAssert parseSize("10.5 MB", res) == 7 + doAssert res == 10_500_000 # decimal metric Mega prefix + doAssert parseSize("64 mib", res) == 6 + doAssert res == 67108864 # 64 shl 20 + doAssert parseSize("1G/h", res, true) == 2 # '/' stops parse + doAssert res == 1073741824 # 1 shl 30, forced binary metric + const prefix = "b" & "kmgtpezy" # byte|bit & lowCase metric-ish prefixes + const scaleM = [1.0, 1e3, 1e6, 1e9, 1e12, 1e15, 1e18, 1e21, 1e24] # 10^(3*idx) + const scaleB = [1.0, 1024, 1048576, 1073741824, 1099511627776.0, # 2^(10*idx) + 1125899906842624.0, 1152921504606846976.0, # ldexp? + 1.180591620717411303424e21, 1.208925819614629174706176e24] + var number: float + var scale = 1.0 + result = parseFloat(s, number) + if number < 0: # While parseFloat accepts negatives .. + result = 0 #.. we do not since sizes cannot be < 0 + if result > 0: + let start = result # Save spot to maybe unwind white to EOS + while result < s.len and s[result] in Whitespace: + inc result + if result < s.len: # Illegal starting char => unity + if (let si = prefix.find(s[result].toLowerAscii); si >= 0): + inc result # Now parse the scale + scale = if alwaysBin: scaleB[si] else: scaleM[si] + if result < s.len and s[result] == 'i': + scale = scaleB[si] # Switch from default to binary-metric + inc result + if result < s.len and s[result].toLowerAscii == 'b': + inc result # Skip optional '[bB]' + else: # Unwind result advancement when there.. + result = start #..is no unit to the end of `s`. + var sizeF = number * scale + 0.5 # Saturate to int64.high when too big + size = if sizeF > 9223372036854774784.0: int64.high else: sizeF.int64 +# Above constant=2^63-1024 avoids C UB; github.com/nim-lang/Nim/issues/20102 or +# stackoverflow.com/questions/20923556/math-pow2-63-1-math-pow2-63-512-is-true + +type + InterpolatedKind* = enum ## Describes for `interpolatedFragments` + ## which part of the interpolated string is + ## yielded; for example in "str$$$var${expr}" + ikStr, ## ``str`` part of the interpolated string + ikDollar, ## escaped ``$`` part of the interpolated string + ikVar, ## ``var`` part of the interpolated string + ikExpr ## ``expr`` part of the interpolated string + +iterator interpolatedFragments*(s: openArray[char]): tuple[kind: InterpolatedKind, + value: string] = + ## Tokenizes the string `s` into substrings for interpolation purposes. + ## + runnableExamples: + var outp: seq[tuple[kind: InterpolatedKind, value: string]] + for k, v in interpolatedFragments(" $this is ${an example} $$"): + outp.add (k, v) + doAssert outp == @[(ikStr, " "), + (ikVar, "this"), + (ikStr, " is "), + (ikExpr, "an example"), + (ikStr, " "), + (ikDollar, "$")] + + var i = 0 + var kind: InterpolatedKind + while true: + var j = i + if j < s.len and s[j] == '$': + if j+1 < s.len and s[j+1] == '{': + inc j, 2 + var nesting = 0 + block curlies: + while j < s.len: + case s[j] + of '{': inc nesting + of '}': + if nesting == 0: + inc j + break curlies + dec nesting + else: discard + inc j + raise newException(ValueError, + "Expected closing '}': " & substr(s.toOpenArray(i, s.high))) + inc i, 2 # skip ${ + kind = ikExpr + elif j+1 < s.len and s[j+1] in IdentStartChars: + inc j, 2 + while j < s.len and s[j] in IdentChars: inc(j) + inc i # skip $ + kind = ikVar + elif j+1 < s.len and s[j+1] == '$': + inc j, 2 + inc i # skip $ + kind = ikDollar + else: + raise newException(ValueError, + "Unable to parse a variable name at " & substr(s.toOpenArray(i, s.high))) + else: + while j < s.len and s[j] != '$': inc j + kind = ikStr + if j > i: + # do not copy the trailing } for ikExpr: + yield (kind, substr(s.toOpenArray(i, j-1-ord(kind == ikExpr)))) + else: + break + i = j + +{.pop.} + + +proc parseBin*[T: SomeInteger](s: string, number: var T, start = 0, + maxLen = 0): int {.noSideEffect.} = + ## Parses a binary number and stores its value in ``number``. + ## + ## Returns the number of the parsed characters or 0 in case of an error. + ## If error, the value of ``number`` is not changed. + ## + ## If ``maxLen == 0``, the parsing continues until the first non-bin character + ## or to the end of the string. Otherwise, no more than ``maxLen`` characters + ## are parsed starting from the ``start`` position. + ## + ## It does not check for overflow. If the value represented by the string is + ## too big to fit into ``number``, only the value of last fitting characters + ## will be stored in ``number`` without producing an error. + runnableExamples: + var num: int + doAssert parseBin("0100_1110_0110_1001_1110_1101", num) == 29 + doAssert num == 5138925 + doAssert parseBin("3", num) == 0 + var num8: int8 + doAssert parseBin("0b_0100_1110_0110_1001_1110_1101", num8) == 32 + doAssert num8 == 0b1110_1101'i8 + doAssert parseBin("0b_0100_1110_0110_1001_1110_1101", num8, 3, 9) == 9 + doAssert num8 == 0b0100_1110'i8 + var num8u: uint8 + doAssert parseBin("0b_0100_1110_0110_1001_1110_1101", num8u) == 32 + doAssert num8u == 237 + var num64: int64 + doAssert parseBin("0100111001101001111011010100111001101001", num64) == 40 + doAssert num64 == 336784608873 + parseBin(s.toOpenArray(start, s.high), number, maxLen) + +proc parseOct*[T: SomeInteger](s: string, number: var T, start = 0, + maxLen = 0): int {.noSideEffect.} = + ## Parses an octal number and stores its value in ``number``. + ## + ## Returns the number of the parsed characters or 0 in case of an error. + ## If error, the value of ``number`` is not changed. + ## + ## If ``maxLen == 0``, the parsing continues until the first non-oct character + ## or to the end of the string. Otherwise, no more than ``maxLen`` characters + ## are parsed starting from the ``start`` position. + ## + ## It does not check for overflow. If the value represented by the string is + ## too big to fit into ``number``, only the value of last fitting characters + ## will be stored in ``number`` without producing an error. + runnableExamples: + var num: int + doAssert parseOct("0o23464755", num) == 10 + doAssert num == 5138925 + doAssert parseOct("8", num) == 0 + var num8: int8 + doAssert parseOct("0o_1464_755", num8) == 11 + doAssert num8 == -19 + doAssert parseOct("0o_1464_755", num8, 3, 3) == 3 + doAssert num8 == 102 + var num8u: uint8 + doAssert parseOct("1464755", num8u) == 7 + doAssert num8u == 237 + var num64: int64 + doAssert parseOct("2346475523464755", num64) == 16 + doAssert num64 == 86216859871725 + parseOct(s.toOpenArray(start, s.high), number, maxLen) + +proc parseHex*[T: SomeInteger](s: string, number: var T, start = 0, + maxLen = 0): int {.noSideEffect.} = + ## Parses a hexadecimal number and stores its value in ``number``. + ## + ## Returns the number of the parsed characters or 0 in case of an error. + ## If error, the value of ``number`` is not changed. + ## + ## If ``maxLen == 0``, the parsing continues until the first non-hex character + ## or to the end of the string. Otherwise, no more than ``maxLen`` characters + ## are parsed starting from the ``start`` position. + ## + ## It does not check for overflow. If the value represented by the string is + ## too big to fit into ``number``, only the value of last fitting characters + ## will be stored in ``number`` without producing an error. + runnableExamples: + var num: int + doAssert parseHex("4E_69_ED", num) == 8 + doAssert num == 5138925 + doAssert parseHex("X", num) == 0 + doAssert parseHex("#ABC", num) == 4 + var num8: int8 + doAssert parseHex("0x_4E_69_ED", num8) == 11 + doAssert num8 == 0xED'i8 + doAssert parseHex("0x_4E_69_ED", num8, 3, 2) == 2 + doAssert num8 == 0x4E'i8 + var num8u: uint8 + doAssert parseHex("0x_4E_69_ED", num8u) == 11 + doAssert num8u == 237 + var num64: int64 + doAssert parseHex("4E69ED4E69ED", num64) == 12 + doAssert num64 == 86216859871725 + parseHex(s.toOpenArray(start, s.high), number, maxLen) + +proc parseIdent*(s: string, ident: var string, start = 0): int = + ## Parses an identifier and stores it in ``ident``. Returns + ## the number of the parsed characters or 0 in case of an error. + ## If error, the value of `ident` is not changed. + runnableExamples: + var res: string + doAssert parseIdent("Hello World", res, 0) == 5 + doAssert res == "Hello" + doAssert parseIdent("Hello World", res, 1) == 4 + doAssert res == "ello" + doAssert parseIdent("Hello World", res, 6) == 5 + doAssert res == "World" + parseIdent(s.toOpenArray(start, s.high), ident) + +proc parseIdent*(s: string, start = 0): string = + ## Parses an identifier and returns it or an empty string in + ## case of an error. + runnableExamples: + doAssert parseIdent("Hello World", 0) == "Hello" + doAssert parseIdent("Hello World", 1) == "ello" + doAssert parseIdent("Hello World", 5) == "" + doAssert parseIdent("Hello World", 6) == "World" + parseIdent(s.toOpenArray(start, s.high)) + +proc parseChar*(s: string, c: var char, start = 0): int = + ## Parses a single character, stores it in `c` and returns 1. + ## In case of error (if start >= s.len) it returns 0 + ## and the value of `c` is unchanged. + runnableExamples: + var c: char + doAssert "nim".parseChar(c, 3) == 0 + doAssert c == '\0' + doAssert "nim".parseChar(c, 0) == 1 + doAssert c == 'n' + parseChar(s.toOpenArray(start, s.high), c) + +proc skipWhitespace*(s: string, start = 0): int {.inline.} = + ## Skips the whitespace starting at ``s[start]``. Returns the number of + ## skipped characters. + runnableExamples: + doAssert skipWhitespace("Hello World", 0) == 0 + doAssert skipWhitespace(" Hello World", 0) == 1 + doAssert skipWhitespace("Hello World", 5) == 1 + doAssert skipWhitespace("Hello World", 5) == 2 + skipWhitespace(s.toOpenArray(start, s.high)) + +proc skip*(s, token: string, start = 0): int {.inline.} = + ## Skips the `token` starting at ``s[start]``. Returns the length of `token` + ## or 0 if there was no `token` at ``s[start]``. + runnableExamples: + doAssert skip("2019-01-22", "2019", 0) == 4 + doAssert skip("2019-01-22", "19", 0) == 0 + doAssert skip("2019-01-22", "19", 2) == 2 + doAssert skip("CAPlow", "CAP", 0) == 3 + doAssert skip("CAPlow", "cap", 0) == 0 + skip(s.toOpenArray(start, s.high), token) + +proc skipIgnoreCase*(s, token: string, start = 0): int = + ## Same as `skip` but case is ignored for token matching. + runnableExamples: + doAssert skipIgnoreCase("CAPlow", "CAP", 0) == 3 + doAssert skipIgnoreCase("CAPlow", "cap", 0) == 3 + skipIgnoreCase(s.toOpenArray(start, s.high), token) + +proc skipUntil*(s: string, until: set[char], start = 0): int {.inline.} = + ## Skips all characters until one char from the set `until` is found + ## or the end is reached. + ## Returns number of characters skipped. + runnableExamples: + doAssert skipUntil("Hello World", {'W', 'e'}, 0) == 1 + doAssert skipUntil("Hello World", {'W'}, 0) == 6 + doAssert skipUntil("Hello World", {'W', 'd'}, 0) == 6 + skipUntil(s.toOpenArray(start, s.high), until) + +proc skipUntil*(s: string, until: char, start = 0): int {.inline.} = + ## Skips all characters until the char `until` is found + ## or the end is reached. + ## Returns number of characters skipped. + runnableExamples: + doAssert skipUntil("Hello World", 'o', 0) == 4 + doAssert skipUntil("Hello World", 'o', 4) == 0 + doAssert skipUntil("Hello World", 'W', 0) == 6 + doAssert skipUntil("Hello World", 'w', 0) == 11 + skipUntil(s.toOpenArray(start, s.high), until) + +proc skipWhile*(s: string, toSkip: set[char], start = 0): int {.inline.} = + ## Skips all characters while one char from the set `toSkip` is found. + ## Returns number of characters skipped. + runnableExamples: + doAssert skipWhile("Hello World", {'H', 'e'}) == 2 + doAssert skipWhile("Hello World", {'e'}) == 0 + doAssert skipWhile("Hello World", {'W', 'o', 'r'}, 6) == 3 + skipWhile(s.toOpenArray(start, s.high), toSkip) + +proc parseUntil*(s: string, token: var string, until: set[char], + start = 0): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of the characters notin `until`. + runnableExamples: + var myToken: string + doAssert parseUntil("Hello World", myToken, {'W', 'o', 'r'}) == 4 + doAssert myToken == "Hell" + doAssert parseUntil("Hello World", myToken, {'W', 'r'}) == 6 + doAssert myToken == "Hello " + doAssert parseUntil("Hello World", myToken, {'W', 'r'}, 3) == 3 + doAssert myToken == "lo " + parseUntil(s.toOpenArray(start, s.high), token, until) + +proc parseUntil*(s: string, token: var string, until: char, + start = 0): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of any character that is not the `until` character. + runnableExamples: + var myToken: string + doAssert parseUntil("Hello World", myToken, 'W') == 6 + doAssert myToken == "Hello " + doAssert parseUntil("Hello World", myToken, 'o') == 4 + doAssert myToken == "Hell" + doAssert parseUntil("Hello World", myToken, 'o', 2) == 2 + doAssert myToken == "ll" + parseUntil(s.toOpenArray(start, s.high), token, until) + +proc parseUntil*(s: string, token: var string, until: string, + start = 0): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of any character that comes before the `until` token. + runnableExamples: + var myToken: string + doAssert parseUntil("Hello World", myToken, "Wor") == 6 + doAssert myToken == "Hello " + doAssert parseUntil("Hello World", myToken, "Wor", 2) == 4 + doAssert myToken == "llo " + parseUntil(s.toOpenArray(start, s.high), token, until) + +proc parseWhile*(s: string, token: var string, validChars: set[char], + start = 0): int {.inline.} = + ## Parses a token and stores it in ``token``. Returns + ## the number of the parsed characters or 0 in case of an error. A token + ## consists of the characters in `validChars`. + runnableExamples: + var myToken: string + doAssert parseWhile("Hello World", myToken, {'W', 'o', 'r'}, 0) == 0 + doAssert myToken.len() == 0 + doAssert parseWhile("Hello World", myToken, {'W', 'o', 'r'}, 6) == 3 + doAssert myToken == "Wor" + parseWhile(s.toOpenArray(start, s.high), token, validChars) + +proc captureBetween*(s: string, first: char, second = '\0', start = 0): string = + ## Finds the first occurrence of ``first``, then returns everything from there + ## up to ``second`` (if ``second`` is '\0', then ``first`` is used). + runnableExamples: + doAssert captureBetween("Hello World", 'e') == "llo World" + doAssert captureBetween("Hello World", 'e', 'r') == "llo Wo" + doAssert captureBetween("Hello World", 'l', start = 6) == "d" + captureBetween(s.toOpenArray(start, s.high), first, second) + +proc parseBiggestInt*(s: string, number: var BiggestInt, start = 0): int {.noSideEffect, raises: [ValueError].} = + ## Parses an integer starting at `start` and stores the value into `number`. + ## Result is the number of processed chars or 0 if there is no integer. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: BiggestInt + doAssert parseBiggestInt("9223372036854775807", res, 0) == 19 + doAssert res == 9223372036854775807 + doAssert parseBiggestInt("-2024_05_09", res) == 11 + doAssert res == -20240509 + doAssert parseBiggestInt("-2024_05_02", res, 7) == 4 + doAssert res == 502 + parseBiggestInt(s.toOpenArray(start, s.high), number) + +proc parseInt*(s: string, number: var int, start = 0): int {.noSideEffect, raises: [ValueError].} = + ## Parses an integer starting at `start` and stores the value into `number`. + ## Result is the number of processed chars or 0 if there is no integer. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: int + doAssert parseInt("-2024_05_02", res) == 11 + doAssert res == -20240502 + doAssert parseInt("-2024_05_02", res, 7) == 4 + doAssert res == 502 + parseInt(s.toOpenArray(start, s.high), number) + + +proc parseSaturatedNatural*(s: string, b: var int, start = 0): int {. + raises: [].} = + ## Parses a natural number into ``b``. This cannot raise an overflow + ## error. ``high(int)`` is returned for an overflow. + ## The number of processed character is returned. + ## This is usually what you really want to use instead of `parseInt`:idx:. + runnableExamples: + var res = 0 + discard parseSaturatedNatural("848", res) + doAssert res == 848 + parseSaturatedNatural(s.toOpenArray(start, s.high), b) + + +proc parseBiggestUInt*(s: string, number: var BiggestUInt, start = 0): int {.noSideEffect, raises: [ValueError].} = + ## Parses an unsigned integer starting at `start` and stores the value + ## into `number`. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: BiggestUInt + doAssert parseBiggestUInt("12", res, 0) == 2 + doAssert res == 12 + doAssert parseBiggestUInt("1111111111111111111", res, 0) == 19 + doAssert res == 1111111111111111111'u64 + parseBiggestUInt(s.toOpenArray(start, s.high), number) + +proc parseUInt*(s: string, number: var uint, start = 0): int {.noSideEffect, raises: [ValueError].} = + ## Parses an unsigned integer starting at `start` and stores the value + ## into `number`. + ## `ValueError` is raised if the parsed integer is out of the valid range. + runnableExamples: + var res: uint + doAssert parseUInt("3450", res) == 4 + doAssert res == 3450 + doAssert parseUInt("3450", res, 2) == 2 + doAssert res == 50 + parseUInt(s.toOpenArray(start, s.high), number) + +proc parseBiggestFloat*(s: string, number: var BiggestFloat, start = 0): int {.noSideEffect.} = + ## Parses a float starting at `start` and stores the value into `number`. + ## Result is the number of processed chars or 0 if a parsing error + ## occurred. + parseFloat(s.toOpenArray(start, s.high), number) + +proc parseFloat*(s: string, number: var float, start = 0): int {.noSideEffect.} = + ## Parses a float starting at `start` and stores the value into `number`. + ## Result is the number of processed chars or 0 if there occurred a parsing + ## error. + runnableExamples: + var res: float + doAssert parseFloat("32", res, 0) == 2 + doAssert res == 32.0 + doAssert parseFloat("32.57", res, 0) == 5 + doAssert res == 32.57 + doAssert parseFloat("32.57", res, 3) == 2 + doAssert res == 57.00 + parseFloat(s.toOpenArray(start, s.high), number) + +iterator interpolatedFragments*(s: string): tuple[kind: InterpolatedKind, + value: string] = + ## Tokenizes the string `s` into substrings for interpolation purposes. + ## + runnableExamples: + var outp: seq[tuple[kind: InterpolatedKind, value: string]] + for k, v in interpolatedFragments(" $this is ${an example} $$"): + outp.add (k, v) + doAssert outp == @[(ikStr, " "), + (ikVar, "this"), + (ikStr, " is "), + (ikExpr, "an example"), + (ikStr, " "), + (ikDollar, "$")] + for x in s.toOa.interpolatedFragments: + yield x + |