Update Interval types

packages/ohm-js/index.d.ts

@@ -394,22 +394,24 @@ declare namespace ohm {
   interface TerminalNode extends Node {}
 
   /**
-   * Interval in input string
+   * An Interval represents a subset of a string.
    */
   interface Interval {
     /**
-     * Input stream of parse
+     * The string containing the interval.
      */
-    inputStream: any;
+    sourceString: string;
 
     /**
-     * Starting index in input
+     * The start index of the interval in `sourceString`.
      */
     startIdx: number;
+
     /**
-     * Ending index in input
+     * The end index of the interval in `sourceString`.
      */
     endIdx: number;
+
     /**
      * Contents of interval
      */
@@ -425,12 +427,6 @@ declare namespace ohm {
      */
     collapsedRight(): Interval;
 
-    /**
-     * Returns a new Interval which contains the same contents as this one,
-     * but with whitespace trimmed from both ends.
-     */
-    trimmed(): Interval;
-
     /**
      * Returns a new Interval that covers this Interval and all the
      * argument Intervals. The new Interval will start at the lowest start
@@ -448,6 +444,30 @@ declare namespace ohm {
      * interval in the source string, including the line and column number.
      */
     getLineAndColumn(): LineAndColumnInfo;
+
+    /**
+     * Returns an array of 0, 1, or 2 intervals that represents the result of the
+     * interval difference operation.
+     */
+    minus(that: Interval): Interval[];
+
+    /**
+     * Returns a new Interval that has the same extent as this one, but which is relative
+     * to `that`, an Interval that fully covers this one.
+     */
+    relativeTo(that: Interval): Interval;
+
+    /**
+     * Returns a new Interval which contains the same contents as this one,
+     * but with whitespace trimmed from both ends.
+     */
+    trimmed(): Interval;
+
+    /**
+     * Returns a new Interval on the same source string, with the given length
+     * and beginning at `startIdx + offset`.
+     */
+    subInterval(offset: number, len: number): Interval;
   }
 
   interface RuleInfo {

packages/ohm-js/scripts/data/index.d.ts.template

@@ -372,22 +372,24 @@ declare namespace ohm {
   interface TerminalNode extends Node {}
 
   /**
-   * Interval in input string
+   * An Interval represents a subset of a string.
    */
   interface Interval {
     /**
-     * Input stream of parse
+     * The string containing the interval.
      */
-    inputStream: any;
+    sourceString: string;
 
     /**
-     * Starting index in input
+     * The start index of the interval in `sourceString`.
      */
     startIdx: number;
+
     /**
-     * Ending index in input
+     * The end index of the interval in `sourceString`.
      */
     endIdx: number;
+
     /**
      * Contents of interval
      */
@@ -403,12 +405,6 @@ declare namespace ohm {
      */
     collapsedRight(): Interval;
 
-    /**
-     * Returns a new Interval which contains the same contents as this one,
-     * but with whitespace trimmed from both ends.
-     */
-    trimmed(): Interval;
-
     /**
      * Returns a new Interval that covers this Interval and all the
      * argument Intervals. The new Interval will start at the lowest start
@@ -426,6 +422,30 @@ declare namespace ohm {
      * interval in the source string, including the line and column number.
      */
     getLineAndColumn(): LineAndColumnInfo;
+
+    /**
+     * Returns an array of 0, 1, or 2 intervals that represents the result of the
+     * interval difference operation.
+     */
+    minus(that: Interval): Interval[];
+
+    /**
+     * Returns a new Interval that has the same extent as this one, but which is relative
+     * to `that`, an Interval that fully covers this one.
+     */
+    relativeTo(that: Interval): Interval;
+
+    /**
+     * Returns a new Interval which contains the same contents as this one,
+     * but with whitespace trimmed from both ends.
+     */
+    trimmed(): Interval;
+
+    /**
+     * Returns a new Interval on the same source string, with the given length
+     * and beginning at `startIdx + offset`.
+     */
+    subInterval(offset: number, len: number): Interval;
   }
 
   interface RuleInfo {

packages/ohm-js/src/Interval.js

@@ -97,8 +97,7 @@ Interval.prototype = {
   },
 
   // Returns a new Interval which contains the same contents as this one,
-  // but with whitespace trimmed from both ends. (This only makes sense when
-  // the input stream is a string.)
+  // but with whitespace trimmed from both ends.
   trimmed() {
     const {contents} = this;
     const startIdx = this.startIdx + contents.match(/^\s*/)[0].length;

packages/ohm-js/test/test-typings.ts

@@ -74,3 +74,26 @@ test('asIteration - #407', t => {
   });
   t.is(s(g.match('abc')).x(), true);
 });
+
+test('Interval typings', t => {
+  const inputStr = ' Sup friend!   ';
+  const matchFailure = g.match(inputStr);
+  t.true(matchFailure.failed());
+
+  const interval = matchFailure.getInterval();
+  interval.startIdx = 1;
+  interval.endIdx = inputStr.length;
+  t.is(interval.sourceString, ' Sup friend!   ');
+  t.is(interval.contents, 'Sup friend!   ');
+  t.is(interval.trimmed().contents, 'Sup friend!');
+
+  const left = interval.collapsedLeft();
+  const right = interval.collapsedRight();
+  t.is(left.startIdx, interval.startIdx);
+  t.is(right.startIdx, interval.endIdx);
+
+  const fat = interval.minus(interval.trimmed());
+  t.is(fat.length, 1);
+  t.is(fat[0].contents, '   ');
+  t.is(fat[0].relativeTo(interval).startIdx, 11);
+});