feat(parse): add ctx getters, add presets, update maybe

thi-ng · Apr 16, 2020 · 02597bf · 02597bf
1 parent bef1d4f
commit 02597bf
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Showing 3 changed files with 26 additions and 5 deletions.
diff --git a/packages/parse/src/combinators/maybe.ts b/packages/parse/src/combinators/maybe.ts
@@ -5,4 +5,4 @@ export const maybe = <T, R = any>(
     parser: Parser<T>,
     fn?: Lift<R>,
     id = "maybe"
-): Parser<T> => (ctx) => parser(ctx) || lift(fn != null ? fn : null, id)(ctx);
+): Parser<T> => (ctx) => parser(ctx) || lift(fn, id)(ctx);
diff --git a/packages/parse/src/constants.ts b/packages/parse/src/constants.ts
@@ -8,9 +8,11 @@ import { oneOf } from "./prims/one-of";
 import { range } from "./prims/range";
 import { xfFloat, xfInt } from "./xform/number";
 
-export const WS = oneOf(" \t\n\r");
+export const WS = oneOf(" \t\n\r", "ws");
+export const WS_0 = zeroOrMore(WS, "ws0");
+export const WS_1 = oneOrMore(WS, "ws1");
 
-export const DIGIT = range<string>("0", "9");
+export const DIGIT = range<string>("0", "9", "digit");
 
 export const HEX_DIGIT = alt([
     DIGIT,
@@ -34,7 +36,7 @@ const EXP = maybe(seq([maybe(oneOf("eE")), SIGN, DIGITS_1]));
 
 const DOT = lit(".");
 
-const FRACT0 = maybe(seq([DOT, maybe(DIGITS_0)]));
+const FRACT0 = maybe(seq([DOT, DIGITS_0]));
 const FRACT1 = seq([DOT, DIGITS_1]);
 
 export const INT = xform(seq([SIGN, DIGITS_1], "int"), xfInt());

diff --git a/packages/parse/src/context.ts b/packages/parse/src/context.ts
@@ -113,8 +113,27 @@ export class ParseContext<T> {
         return this._curr.state.done;
     }
 
+    /**
+     * Returns root node.
+     */
+    get root() {
+        return this._scopes[0];
+    }
+
+    /**
+     * Returns root node's `result` or `undefined`.
+     */
     get result() {
-        return this._curr.children ? this._curr.children[0].result : undefined;
+        const children = this.root.children;
+        return children ? children[0].result : undefined;
+    }
+
+    /**
+     * Returns root node's children or `undefined`.
+     */
+    get children() {
+        const children = this.root.children;
+        return children ? children[0].children : undefined;
     }
 }