lexbase

This module implements a base object of a lexer with efficient buffer handling. Only at line endings checks are necessary if the buffer needs refilling.

Types

BaseLexer = object of RootObj
  bufpos*: int                 ## the current position within the buffer
  buf*: string                 ## the buffer itself
  input: Stream                ## the input stream
  lineNumber*: int             ## the current line number
  sentinel: int
  lineStart: int
  offsetBase*: int
  refillChars: set[char]
the base lexer. Inherit your lexer from this object.   Source Edit

Consts

EndOfFile = '\x00'
end of file marker   Source Edit
NewLines = {'\c', '\n'}
  Source Edit

Procs

proc close(L: var BaseLexer) {...}{.raises: [Exception, IOError, OSError],
                           tags: [WriteIOEffect].}
closes the base lexer. This closes L's associated stream too.   Source Edit
proc handleCR(L: var BaseLexer; pos: int): int {...}{.raises: [Defect, IOError, OSError],
    tags: [ReadIOEffect].}
Call this if you scanned over 'c' in the buffer; it returns the position to continue the scanning from. pos must be the position of the 'c'.   Source Edit
proc handleLF(L: var BaseLexer; pos: int): int {...}{.raises: [Defect, IOError, OSError],
    tags: [ReadIOEffect].}
Call this if you scanned over 'L' in the buffer; it returns the position to continue the scanning from. pos must be the position of the 'L'.   Source Edit
proc handleRefillChar(L: var BaseLexer; pos: int): int {...}{.
    raises: [Defect, IOError, OSError], tags: [ReadIOEffect].}
Call this if a terminator character other than a new line is scanned at pos; it returns the position to continue the scanning from.   Source Edit
proc open(L: var BaseLexer; input: Stream; bufLen: int = 8192;
         refillChars: set[char] = NewLines) {...}{.raises: [Defect, IOError, OSError],
    tags: [ReadIOEffect].}
inits the BaseLexer with a stream to read from.   Source Edit
proc getColNumber(L: BaseLexer; pos: int): int {...}{.raises: [], tags: [].}
retrieves the current column.   Source Edit
proc getCurrentLine(L: BaseLexer; marker: bool = true): string {...}{.raises: [], tags: [].}
retrieves the current line.   Source Edit