#
#
# The Nim Compiler
# (c) Copyright 2012 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## Serialization utilities for the compiler.
import strutils
proc c_sprintf(buf, frmt: cstring) {.importc: "sprintf", header: "<stdio.h>", nodecl, varargs.}
proc toStrMaxPrecision*(f: BiggestFloat): string =
if f != f:
result = "NAN"
elif f == 0.0:
result = "0.0"
elif f == 0.5 * f:
if f > 0.0: result = "INF"
else: result = "-INF"
else:
var buf: array[0..80, char]
c_sprintf(buf, "%#.16e", f)
result = $buf
proc encodeStr*(s: string, result: var string) =
for i in countup(0, len(s) - 1):
case s[i]
of 'a'..'z', 'A'..'Z', '0'..'9', '_': add(result, s[i])
else: add(result, '\\' & toHex(ord(s[i]), 2))
proc hexChar(c: char, xi: var int) =
case c
of '0'..'9': xi = (xi shl 4) or (ord(c) - ord('0'))
of 'a'..'f': xi = (xi shl 4) or (ord(c) - ord('a') + 10)
of 'A'..'F': xi = (xi shl 4) or (ord(c) - ord('A') + 10)
else: discard
proc decodeStr*(s: cstring, pos: var int): string =
var i = pos
result = ""
while true:
case s[i]
of '\\':
inc(i, 3)
var xi = 0
hexChar(s[i-2], xi)
hexChar(s[i-1], xi)
add(result, chr(xi))
of 'a'..'z', 'A'..'Z', '0'..'9', '_':
add(result, s[i])
inc(i)
else: break
pos = i
const
chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
# since negative numbers require a leading '-' they use up 1 byte. Thus we
# subtract/add `vintDelta` here to save space for small negative numbers
# which are common in ROD files:
const
vintDelta = 5
template encodeIntImpl(self: expr) =
var d: char
var v = x
var rem = v mod 190
if rem < 0:
add(result, '-')
v = - (v div 190)
rem = - rem
else:
v = v div 190
var idx = int(rem)
if idx < 62: d = chars[idx]
else: d = chr(idx - 62 + 128)
if v != 0: self(v, result)
add(result, d)
proc encodeVBiggestIntAux(x: BiggestInt, result: var string) =
## encode a biggest int as a variable length base 190 int.
encodeIntImpl(encodeVBiggestIntAux)
proc encodeVBiggestInt*(x: BiggestInt, result: var string) =
## encode a biggest int as a variable length base 190 int.
encodeVBiggestIntAux(x +% vintDelta, result)
# encodeIntImpl(encodeVBiggestInt)
proc encodeVIntAux(x: int, result: var string) =
## encode an int as a variable length base 190 int.
encodeIntImpl(encodeVIntAux)
proc encodeVInt*(x: int, result: var string) =
## encode an int as a variable length base 190 int.
encodeVIntAux(x +% vintDelta, result)
template decodeIntImpl() =
var i = pos
var sign = - 1
assert(s[i] in {'a'..'z'