feat: more parser + Expr type

1 files changed, 42 insertions, 49 deletions

diff --git a/src/index.ts b/src/index.ts
index a9b3409..3dc572b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,55 +1,48 @@
-import { flow, identity, pipe } from 'fp-ts/function'
-import { Either, left, right, map, chain, mapLeft, fold, orElse } from 'fp-ts/Either'
+import { constant, flow, identity, pipe } from 'fp-ts/function'
+import {mapTo, symbol} from './parser'
 
-type char = string
+export const start = mapTo(symbol('^'), constant({ tag: 'Start' } as Expr))
+export const end = mapTo(symbol('$'), constant({ tag: 'End' } as Expr))
+export const anyItem = mapTo(symbol(','), constant({ tag: 'AnyItem' } as Expr))
+export const nextItem = mapTo(symbol(','), constant({ tag: 'NextItem' } as Expr))
+// export const optional = mapTo(symbol('?'), constant({ tag: 'Optional' } as Expr))
+// export const zeroOrMore = mapTo(symbol('*'), constant({ tag: 'ZeroOrMore' } as Expr))
+// export const oneOrMore = mapTo(symbol('+'), constant({ tag: 'OneOrMore' } as Expr))
 
-type ParserResult<T> = [T, string]
-type ParserError = [string, string]
-type Parser<T> = (input: string) => Either<ParserError, ParserResult<T>>
+type Expr =
+  | { tag: 'Start' }
+  | { tag: 'End' }
+  | { tag: 'Optional' }
+  | { tag: 'OneOrMore' }
+  | { tag: 'ZeroOrMore' }
+  | { tag: 'NextItem' }
+  | { tag: 'AnyItem' }
+  | { tag: 'Or' }
+  | { tag: 'String' }
+  | { tag: 'Number' }
+  | { tag: 'Bool' }
+  | { tag: 'Truthy' }
+  | { tag: 'Falsey' }
 
-export const many0 = <T>(parser: Parser<T>): Parser<Array<T>> => flow(
-  parser,
-  chain(([a, nextInput]) =>
-    pipe(
-      nextInput,
-      many0(parser),
-      map(([ls, inp]): ParserResult<T[]> => [[a, ...ls], inp]),
-    )
-  ),
-  orElse(([_, inp]) => right([[] as T[], inp]))
-)
+/*
 
-export const many1 = <T>(parser: Parser<T>): Parser<Array<T>> => flow(
-  many0(parser),
-  chain(([res, inp]) =>
-    res.length > 0 ? right([res, inp]) : left([`many1 failed to parse at ${inp}`, inp]))
-)
+^ $ => start and end of list
+? => optional
+. => any item
+* => 0 or more instances
++ => 1 or more instances
+{3,6} => 3 to 6 instances
+\s => string
+\n => number
+\b => boolean
+\T => truthy
+\F => falsey
+(> 5) => number greater than
+(< 5) => number less than
+, => followed by
+[name x] => apply x on property `name`
+| => or
+/x/ => match regular expression (string values in list)
 
-export const satify_char = (f: (c: char) => boolean): Parser<char> => (input: string) => {
-  const c = input.charAt(0)
-  if (f(c)) return right([c, input.slice(1)])
-  return left([`Expected to satisfy ${f}, got "${c}"`, input])
-};
-
-export const digit = satify_char(c => /^[0-9]$/g.test(c))
-
-export const integer: Parser<number> = flow(
-  many1(digit),
-  map(([ds, input]) => [parseInt(ds.join(''), 10), input])
-)
-
-export const or = <T>(parsers: Parser<T>[]): Parser<T> => {
-  const ppp = ([p, ...ps]: Parser<T>[]) => flow(
-    p,
-    orElse(([_, inp]) => or(ps)(inp))
-  )
-
-  return parsers.length > 0 ? ppp(parsers) : (inp: string) => left(['unable to match', inp])
-}
-
-export const space = satify_char(c => c === ' ')
-export const newline = satify_char(c => c === '\n')
-export const tab = satify_char(c => c === '\t')
-
-export const whitespace = or([space, newline, tab])
+*/