feat(eval): implements sequence

2 files changed, 33 insertions, 3 deletions

diff --git a/src/eval/index.ts b/src/eval/index.ts
index d0d7363..efede36 100644
--- a/src/eval/index.ts
+++ b/src/eval/index.ts
@@ -1,5 +1,5 @@
 import { identity, pipe } from 'fp-ts/function'
-import { takeLeftWhile, zip } from 'fp-ts/lib/Array'
+import { filter, takeLeftWhile, zip, zipWith } from 'fp-ts/lib/Array'
 import {
   chain,
   getOrElseW,
@@ -35,9 +35,9 @@ const checkExpr = <T>(
   index: number,
   skip: (
     n: index,
-  ) => (m: MatchGroupIndexed<T | T[]>[]) => MatchGroupIndexed<T | T[]>[] = _ =>
+  ) => (m: MatchGroupIndexed<any>[]) => MatchGroupIndexed<any>[] = _ =>
     identity,
-): MatchGroupIndexed<T | T[]>[] => {
+): MatchGroupIndexed<any>[] => {
   return pipe(
     expr,
     match<MatchGroupIndexed<any>[], Expr>({
@@ -111,6 +111,26 @@ const checkExpr = <T>(
         )
       },
 
+      Sequence: ({ exprs }) => {
+        const getGroups = () => {
+          if (exprs.length > list.length) return []
+
+          const indexed = <T>(ls: T[]): Array<[number, T]> => ls.map((x, i) => [i, x])
+          const result = pipe(
+            zipWith(exprs, indexed(list), (expr, [i, val]) => checkExpr(expr, val, list, index + i)),
+            filter(matches => !!matches.length),
+          )
+          if (result.length !== exprs.length) return []
+
+          return [group(result, index)]
+        };
+
+        return pipe(
+          getGroups(),
+          skip(exprs.length || 1),
+        )
+      },
+
       _: _ => { throw new Error(`TODO: ${expr.tag} not implemented for match`) },
     }),
   )
diff --git a/tests/basic.spec.ts b/tests/basic.spec.ts
index 3c49267..482428a 100644
--- a/tests/basic.spec.ts
+++ b/tests/basic.spec.ts
@@ -120,5 +120,15 @@ describe('Basic tests', () => {
         { value: [{ v: 1 }], index: 10 },
       ])
     })
+
+    it('should match sequence of matchers', () => {
+      expect(
+        matchAll(/ true, \n, \s /, [true, 5, 'five', 1, 2, 3, true, 7, 'seven'])
+          .groups,
+      ).toEqual([
+        { value: [ [{ value: true, index: 0 }], [{ value: 5, index: 1 }], [{ value: 'five', index: 2 }] ], index: 0 },
+        { value: [ [{ value: true, index: 6 }], [{ value: 7, index: 7 }], [{ value: 'seven', index: 8 }] ], index: 6 },
+      ])
+    })
   })
 })