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Parsing > Parser > * Parser

* Parser -- repetition of a parser

Synopsis

Usage:
*p
Operator: *
Inputs:
- p, a parser
Outputs:
- a parser, a parser that will feed its tokens through p, and then when further tokens are not accepted, it will start over with a fresh copy of p. The value returned is the sequence of values returned by each instance of p.

Description

i1 : (* constParser "abc" : charAnalyzer) "abcabcabc"

o1 = (abc, abc, abc)

o1 : Sequence

Code

-- ../../../../Macaulay2/packages/Parsing.m2:124-135
*Parser := p -> (
     f := (vals,current) -> new Parser from (c -> (
               if c === null then (
                    if current === null then vals
                    else if (val := current null) =!= null then append(vals,val)
                    )
               else (
                    if current === null then (f(vals,p)) c
                    else (
                         q := current c;
                         if q =!= null then return f(vals,q);
                         if (val = current null) =!= null then (f(append(vals,val),)) c))))

See also

constParser -- produce a parser that accepts a fixed string, one character at a time
charAnalyzer -- a lexical analyzer that provides characters from a string one at a time
Parser : Analyzer -- combine a parser with a lexical analyzer to make a complete system