diff options
Diffstat (limited to 'lib/pure/parseutils.nim')
| -rw-r--r-- | lib/pure/parseutils.nim | 158 |
1 files changed, 83 insertions, 75 deletions
diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim index 484ba5184..06ee07aa8 100644 --- a/lib/pure/parseutils.nim +++ b/lib/pure/parseutils.nim @@ -231,88 +231,96 @@ proc parseInt*(s: string, number: var int, start = 0): int {. else: number = int(res) -proc tenToThePowerOf(b: int): BiggestFloat = - var b = b - var a = 10.0 - result = 1.0 - while true: - if (b and 1) == 1: - result *= a - b = b shr 1 - if b == 0: break - a *= a +when defined(nimParseBiggestFloatMagic): + proc parseBiggestFloat*(s: string, number: var BiggestFloat, start = 0): int {. + magic: "ParseBiggestFloat", importc: "nimParseBiggestFloat", 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. +else: + proc tenToThePowerOf(b: int): BiggestFloat = + var b = b + var a = 10.0 + result = 1.0 + while true: + if (b and 1) == 1: + result *= a + b = b shr 1 + if b == 0: break + a *= a -proc parseBiggestFloat*(s: string, number: var BiggestFloat, start = 0): int {. - rtl, extern: "npuParseBiggestFloat", noSideEffect.} = - ## parses a float starting at `start` and stores the value into `number`. - ## Result is the number of processed chars or 0 if there occured a parsing - ## error. - var - esign = 1.0 - sign = 1.0 - i = start - exponent: int - flags: int - number = 0.0 - if s[i] == '+': inc(i) - elif s[i] == '-': - sign = -1.0 - inc(i) - if s[i] == 'N' or s[i] == 'n': - if s[i+1] == 'A' or s[i+1] == 'a': - if s[i+2] == 'N' or s[i+2] == 'n': - if s[i+3] notin IdentChars: - number = NaN - return i+3 - start - return 0 - if s[i] == 'I' or s[i] == 'i': - if s[i+1] == 'N' or s[i+1] == 'n': - if s[i+2] == 'F' or s[i+2] == 'f': - if s[i+3] notin IdentChars: - number = Inf*sign - return i+3 - start - return 0 - while s[i] in {'0'..'9'}: - # Read integer part - flags = flags or 1 - number = number * 10.0 + toFloat(ord(s[i]) - ord('0')) - inc(i) - while s[i] == '_': inc(i) - # Decimal? - if s[i] == '.': - var hd = 1.0 - inc(i) - while s[i] in {'0'..'9'}: - # Read fractional part - flags = flags or 2 - number = number * 10.0 + toFloat(ord(s[i]) - ord('0')) - hd = hd * 10.0 - inc(i) - while s[i] == '_': inc(i) - number = number / hd # this complicated way preserves precision - # Again, read integer and fractional part - if flags == 0: return 0 - # Exponent? - if s[i] in {'e', 'E'}: - inc(i) - if s[i] == '+': - inc(i) + proc parseBiggestFloat*(s: string, number: var BiggestFloat, start = 0): int {. + rtl, extern: "npuParseBiggestFloat", noSideEffect.} = + ## parses a float starting at `start` and stores the value into `number`. + ## Result is the number of processed chars or 0 if there occured a parsing + ## error. + var + esign = 1.0 + sign = 1.0 + i = start + exponent: int + flags: int + number = 0.0 + if s[i] == '+': inc(i) elif s[i] == '-': - esign = -1.0 + sign = -1.0 inc(i) - if s[i] notin {'0'..'9'}: + if s[i] == 'N' or s[i] == 'n': + if s[i+1] == 'A' or s[i+1] == 'a': + if s[i+2] == 'N' or s[i+2] == 'n': + if s[i+3] notin IdentChars: + number = NaN + return i+3 - start + return 0 + if s[i] == 'I' or s[i] == 'i': + if s[i+1] == 'N' or s[i+1] == 'n': + if s[i+2] == 'F' or s[i+2] == 'f': + if s[i+3] notin IdentChars: + number = Inf*sign + return i+3 - start return 0 while s[i] in {'0'..'9'}: - exponent = exponent * 10 + ord(s[i]) - ord('0') + # Read integer part + flags = flags or 1 + number = number * 10.0 + toFloat(ord(s[i]) - ord('0')) inc(i) while s[i] == '_': inc(i) - # Calculate Exponent - let hd = tenToThePowerOf(exponent) - if esign > 0.0: number = number * hd - else: number = number / hd - # evaluate sign - number = number * sign - result = i - start + # Decimal? + if s[i] == '.': + var hd = 1.0 + inc(i) + while s[i] in {'0'..'9'}: + # Read fractional part + flags = flags or 2 + number = number * 10.0 + toFloat(ord(s[i]) - ord('0')) + hd = hd * 10.0 + inc(i) + while s[i] == '_': inc(i) + number = number / hd # this complicated way preserves precision + # Again, read integer and fractional part + if flags == 0: return 0 + # Exponent? + if s[i] in {'e', 'E'}: + inc(i) + if s[i] == '+': + inc(i) + elif s[i] == '-': + esign = -1.0 + inc(i) + if s[i] notin {'0'..'9'}: + return 0 + while s[i] in {'0'..'9'}: + exponent = exponent * 10 + ord(s[i]) - ord('0') + inc(i) + while s[i] == '_': inc(i) + # Calculate Exponent + let hd = tenToThePowerOf(exponent) + if esign > 0.0: number = number * hd + else: number = number / hd + # evaluate sign + number = number * sign + result = i - start + proc parseFloat*(s: string, number: var float, start = 0): int {. rtl, extern: "npuParseFloat", noSideEffect.} = |