feat: implements manyTill parser combinator

2 files changed, 23 insertions, 1 deletions

diff --git a/src/parser/utils.ts b/src/parser/utils.ts
index 4b68aff..4e2c9d6 100644
--- a/src/parser/utils.ts
+++ b/src/parser/utils.ts
@@ -3,7 +3,7 @@ import * as Either from 'fp-ts/Either'
 import * as Option from 'fp-ts/Option'
 import { fst, mapFst, mapSnd, snd } from 'fp-ts/Tuple'
 import { eq } from '../utils'
-import { prepend } from 'fp-ts/Array'
+import { flatten, prepend } from 'fp-ts/Array'
 
 export type char = string
 
@@ -29,6 +29,19 @@ export const sepBy1 = <T>(sep: Parser<any>, parser: Parser<T>): Parser<T[]> =>
     ),
   )
 
+export const not = (parser: Parser<any>): Parser<null> => (input: string) =>
+  pipe(
+    input,
+    parser,
+    Either.fold(
+      ([_left, inp]) => Either.right([null, inp]),
+      ([_right, inp]) => Either.left(['`not` parser failed. Match found', inp])
+    ),
+  )
+
+export const manyTill = <T>(parser: Parser<T>, end: Parser<any>): Parser<T[]> =>
+  mapTo(pair(many0(suffixed(parser, not(end))), parser), ([xs, l]) => xs.concat([l]))
+
 export const many0 = <T>(parser: Parser<T>): Parser<Array<T>> =>
   flow(
     parser,
diff --git a/tests/parser.spec.ts b/tests/parser.spec.ts
index 0abb1a0..0506be0 100644
--- a/tests/parser.spec.ts
+++ b/tests/parser.spec.ts
@@ -4,10 +4,17 @@ import {
   whitespace,
   whitespaces0,
   delimited,
+  not,
+  symbol,
+  satifyChar,
+  matchChar,
+  manyTill,
+  pair,
 } from '../src/parser/utils'
 import { parser } from '../src/parser'
 import { none, some } from 'fp-ts/Option'
 import { Expr, Literal } from '../src/types'
+import {jlog} from '../src/utils'
 
 const wrap = (e: Expr) => right([[none, e, none], ''])
 const grouped = (l: Expr[]) => wrap(Expr.Group({ exprs: l }))
@@ -16,6 +23,8 @@ const groupedAlt = (l: Expr[]) => wrap(Expr.Or({ exprs: l }))
 describe('Parser', () => {
   it('should do shit', () => {
     // jlog(parser(/ -2.05|\n2|true|\s|\T /.source))
+    //const p = pair(symbol('a'), symbol('b'))
+    //jlog(manyTill(p, matchChar('!'))('ab ab ab ab! nice nice'))
   })
 
   it('should do shit', () => {