by_split: Applying a parser to a split string

In parcr: Construct Parsers for Structured Text Files

Applying a parser to a split string

Description

Splits a string by using a split pattern and then applies the parser p to the resulting character vector. If finish = TRUE then the parser should completely consume its input, otherwise the parser fails. If finish = FALSE then any remaining part of the string is discarded.

Usage

by_split(p, split, finish = TRUE, fixed = FALSE, perl = FALSE)

Arguments

p	A parser.
split	a string (or object which can be coerced to such) containing regular expression(s) (unless fixed = TRUE) to use for splitting. If empty matches occur, in particular if split has length 0, x is split into single characters.
finish	logical. Should the parser completely consume the string? Defaults to TRUE.
fixed	logical. If TRUE match split exactly, otherwise use regular expressions. Has priority over perl.
perl	logical. Should Perl-compatible regexps be used?

Details

The function base::strsplit() is used to perform the splitting. The parameters split, fixed and perl are passed on to that function.

Value

A parser.

See Also

base::strsplit(), by_symbol()

Examples

by_split((literal("a") %then% literal("b")),"\\t") ("a\tb") # success
by_split((literal("a") %then% literal("b")),"\\t") ("a\tb\tc") # failure
by_split((literal("a") %then% literal("b")),"\\t", finish=FALSE) ("a\tb\tc") # success

parcr documentation built on June 22, 2024, 10:31 a.m.