feat(parse): add/update combinators

- add startsWith, endsWith, entireLine, entirely - add wrap() - rename dalt/dseq => altD/seqD
thi-ng · Apr 19, 2020 · e4eab03 · e4eab03
1 parent 719b437
commit e4eab03
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Showing 4 changed files with 26 additions and 2 deletions.
diff --git a/packages/parse/src/combinators/alt.ts b/packages/parse/src/combinators/alt.ts
@@ -11,4 +11,4 @@ export const alt = <T>(parsers: Parser<T>[]): Parser<T> => (ctx) => {
     return false;
 };
 
-export const dalt = <T>(parsers: Parser<T>[]) => discard(alt(parsers));
+export const altD = <T>(parsers: Parser<T>[]) => discard(alt(parsers));
diff --git a/packages/parse/src/combinators/boundary.ts b/packages/parse/src/combinators/boundary.ts
@@ -0,0 +1,13 @@
+import { Parser } from "../api";
+import { inputEnd, inputStart, lineEnd, lineStart } from "../prims/anchor";
+import { seq } from "./seq";
+
+export const startsWith = <T>(parser: Parser<T>) => seq([inputStart, parser]);
+
+export const endsWith = <T>(parser: Parser<T>) => seq([parser, inputEnd]);
+
+export const entireLine = (parser: Parser<string>) =>
+    seq([lineStart, parser, lineEnd]);
+
+export const entirely = <T>(parser: Parser<T>) =>
+    seq([inputStart, parser, inputEnd]);
diff --git a/packages/parse/src/combinators/seq.ts b/packages/parse/src/combinators/seq.ts
@@ -14,4 +14,4 @@ export const seq = <T>(parsers: Parser<T>[], id = "seq"): Parser<T> => (
     return ctx.end();
 };
 
-export const dseq = <T>(parsers: Parser<T>[]) => discard(seq(parsers));
+export const seqD = <T>(parsers: Parser<T>[]) => discard(seq(parsers));
diff --git a/packages/parse/src/combinators/wrap.ts b/packages/parse/src/combinators/wrap.ts
@@ -0,0 +1,11 @@
+import { Parser } from "../api";
+import { litD } from "../prims/lit";
+import { hoist } from "../xform/hoist";
+import { seq } from "./seq";
+
+export const wrap = <T>(
+    parser: Parser<T>,
+    pre: T,
+    post: T = pre,
+    id = "wrap"
+) => hoist(seq([litD(pre), parser, litD(post)], id));