Files
Nim/lib/impure/nre/private/util.nim
2017-07-25 09:28:23 +02:00

64 lines
1.7 KiB
Nim

## INTERNAL FILE FOR USE ONLY BY nre.nim.
import tables
proc fget*[K, V](self: Table[K, V], key: K): V =
if self.hasKey(key):
return self[key]
else:
raise newException(KeyError, "Key does not exist in table: " & $key)
const Ident = {'a'..'z', 'A'..'Z', '0'..'9', '_', '\128'..'\255'}
const StartIdent = Ident - {'0'..'9'}
proc checkNil(arg: string): string =
if arg == nil:
raise newException(ValueError, "Cannot use nil capture")
else:
return arg
template formatStr*(howExpr, namegetter, idgetter): untyped =
let how = howExpr
var val = newStringOfCap(how.len)
var i = 0
var lastNum = 1
while i < how.len:
if how[i] != '$':
val.add(how[i])
i += 1
else:
if how[i + 1] == '$':
val.add('$')
i += 2
elif how[i + 1] == '#':
var id {.inject.} = lastNum
val.add(checkNil(idgetter))
lastNum += 1
i += 2
elif how[i + 1] in {'0'..'9'}:
i += 1
var id {.inject.} = 0
while i < how.len and how[i] in {'0'..'9'}:
id += (id * 10) + (ord(how[i]) - ord('0'))
i += 1
val.add(checkNil(idgetter))
lastNum = id + 1
elif how[i + 1] in StartIdent:
i += 1
var name {.inject.} = ""
while i < how.len and how[i] in Ident:
name.add(how[i])
i += 1
val.add(checkNil(namegetter))
elif how[i + 1] == '{':
i += 2
var name {.inject.} = ""
while i < how.len and how[i] != '}':
name.add(how[i])
i += 1
i += 1
val.add(checkNil(namegetter))
else:
raise newException(Exception, "Syntax error in format string at " & $i)
val