new.parser: Creates an instance of a new PEG parser.

In mslegrand/pegr: PEG PARSER

Description

Creates an instance of a new PEG parser.

Usage

new.parser(peg.data.frame = NULL, record.mode = FALSE, action.exe = FALSE)

Arguments

peg.data.frame,	a data frame with rules to populate the parser. (default is NULL) A peg.data.frame consists of the following fields: rule.id (mandatory), The column containing the rule's id. (NA values not allowed) rule.source (mandatory), The column containing the rule's definition (NA values not allowed) rule.description, (optional) The column containing any rules description (may have NA values) action.specification, (optional) The column containing the rule specifiation. May be either a valid inline action or the name of an existing rule (Set to NA if e no action is associated with this rule.)
record.mode,	when set to TRUE, will keep a record to display with tree or plot. (default is FALSE)
action.exe,	when set to TRUE, all actions will be executed unless overridden by command line. (default is FALSE)

Value

Returns a new instance of a PEG parser

See Also

as.data.frame

Examples

#Create an empty parser
parser<-new.parser()
peg<-add_rule(parser, "Any<-.")
rule_ids(parser)  # returns "Any"

#Create a parser from a data.frame
fn<-function(x){list()}
df<-data.frame(
rule.id=c('A','B'),
rule.source=c("A<-'a'", "B<-'b'"),
rule.description=c("aaa",NA),
action.type=c("Inline","External"),
action.specification=c("list()", "fn"),
stringsAsFactors=FALSE)
peg<-new.parser(df)

mslegrand/pegr documentation built on May 23, 2019, 7:53 a.m.