hiparse: Hybrid Index, parsing

In kindlychung/ff: memory-efficient storage of large data on disk and fast access functions

Description

hiparse implements the parsing done in Hybrid Index Preprocessing in order to avoid RAM for expanding index expressions. Not to be called directly

Usage

hiparse(x, envir, first = as.integer(NA), last = as.integer(NA))

Arguments

x	an index expression, precisely: call
envir	the environemtn in which to evaluate components of the index expression
first	first index position found so far
last	last index position found so far

Details

This primitive parser recognises the following tokens: numbers like 1, symbols like x, the colon sequence operator : and the concat operator c. hiparse will Recall until the index expression is parsed or an unknown token is found. If an unknown token is found, hiparse evluates it, inspects it and either accepts it or throws an error, catched by as.hi.call, which falls back to evaluating the index expression and dispatching (again) an appropriate as.hi method. Reasons for suspending the parsing: if the inspected token is of class 'hi', 'ri', 'bit', 'bitwhich', 'is.logical', 'is.character', 'is.matrix' or has length>16.

Value

undefined (and redefined as needed by as.hi.call)

Author(s)

Jens Oehlschl<c3><a4>gel

See Also

hi, as.hi.call

kindlychung/ff documentation built on May 20, 2019, 9:58 a.m.