feat(strings): add int/intLocale, vector formatters

- add optional arg for float() for special NaN/Inf handling
thi-ng · Jan 31, 2021 · ac55fe0 · ac55fe0
1 parent 4302f58
commit ac55fe0
Show file tree

Hide file tree

Showing 4 changed files with 76 additions and 6 deletions.
diff --git a/packages/strings/src/float.ts b/packages/strings/src/float.ts
@@ -3,19 +3,22 @@ import type { Stringer } from "./api";
 import { padLeft } from "./pad-left";
 
 /**
- * Returns {@link Stringer} which formats numbers to given precision.
- * Exceptions:
+ * Returns {@link Stringer} which formats numbers to given precision. If
+ * `special` is true, then exceptional handling for:
  *
  * - NaN => "NaN"
  * - Infinity => "+/-∞"
  *
  * @param len - number of fractional digits
- * @kind function
+ * @param special - true, if special handling for NaN/Infinity values
  */
 export const float: (
-    prec: number
-) => Stringer<number> = memoizeJ((prec) => (x: number) =>
-    nanOrInf(x) || x.toFixed(prec)
+    prec: number,
+    special?: boolean
+) => Stringer<number> = memoizeJ((prec, special = false) =>
+    special
+        ? (x: number) => nanOrInf(x) || x.toFixed(prec)
+        : (x: number) => x.toFixed(prec)
 );
 
 /**

diff --git a/packages/strings/src/index.ts b/packages/strings/src/index.ts
@@ -9,6 +9,7 @@ export * from "./float";
 export * from "./format";
 export * from "./groups";
 export * from "./hollerith";
+export * from "./int";
 export * from "./interpolate";
 export * from "./join";
 export * from "./pad-left";
@@ -28,5 +29,6 @@ export * from "./truncate";
 export * from "./truncate-left";
 export * from "./units";
 export * from "./uuid";
+export * from "./vector";
 export * from "./wrap";
 export * from "./word-wrap";
diff --git a/packages/strings/src/int.ts b/packages/strings/src/int.ts
@@ -0,0 +1,10 @@
+import { memoizeJ } from "@thi.ng/memoize";
+import type { Stringer } from "./api";
+
+export const int: Stringer<number> = (x) => String(Math.trunc(x));
+
+export const intLocale: (
+    locale?: string
+) => Stringer<number> = memoizeJ((locale) => (x) =>
+    Math.trunc(x).toLocaleString(locale)
+);
diff --git a/packages/strings/src/vector.ts b/packages/strings/src/vector.ts
@@ -0,0 +1,55 @@
+import { isNumber } from "@thi.ng/checks";
+import { memoizeJ } from "@thi.ng/memoize";
+import type { Stringer } from "./api";
+import { float } from "./float";
+
+/**
+ * Higher order formatter for n-D vectors, with each element formatted using
+ * `prec` and using optional delimiter and pre/postfixes.
+ *
+ * @size - vector size (optimized for size 1-4)
+ * @prec - precision (see {@link float}) or existing number formatter
+ * @delim - delimiter (default: `,`)
+ * @pre - prefix (default: `[`)
+ * @post - prefix (default: `]`)
+ */
+export const vector: (
+    size: number,
+    prec?: number | Stringer<number>,
+    delim?: string,
+    pre?: string,
+    post?: string
+) => Stringer<ArrayLike<number>> = memoizeJ(
+    (
+        size: number,
+        prec: number | Stringer<number> = 3,
+        d = ",",
+        pre = "[",
+        post = "]"
+    ) => {
+        const f = isNumber(prec) ? float(prec) : prec;
+        switch (size) {
+            case 1:
+                return (v: ArrayLike<number>) => `${pre}${f(v[0])}${post}`;
+            case 2:
+                return (v: ArrayLike<number>) =>
+                    `${pre}${f(v[0])}${d}${f(v[1])}${post}`;
+            case 3:
+                return (v: ArrayLike<number>) =>
+                    `${pre}${f(v[0])}${d}${f(v[1])}${d}${f(v[2])}${post}`;
+            case 4:
+                return (v: ArrayLike<number>) =>
+                    `${pre}${f(v[0])}${d}${f(v[1])}${d}${f(v[2])}${d}${f(
+                        v[3]
+                    )}${post}`;
+            default:
+                return (v: ArrayLike<number>) => {
+                    const res = [];
+                    for (let i = 0; i < v.length; i++) {
+                        res.push(f(v[i]));
+                    }
+                    return `${pre}${res.join(d)}${post}`;
+                };
+        }
+    }
+);