merge 036, everything broken

sdk/lib/util/getRandomCharInSet.ts

@@ -0,0 +1,98 @@
+// a,g,h,A-Z,,,,-
+
+import * as crypto from "crypto"
+export function getRandomCharInSet(charset: string): string {
+  const set = stringToCharSet(charset)
+  let charIdx = crypto.randomInt(0, set.len)
+  for (let range of set.ranges) {
+    if (range.len > charIdx) {
+      return String.fromCharCode(range.start.charCodeAt(0) + charIdx)
+    }
+    charIdx -= range.len
+  }
+  throw new Error("unreachable")
+}
+function stringToCharSet(charset: string): CharSet {
+  let set: CharSet = { ranges: [], len: 0 }
+  let start: string | null = null
+  let end: string | null = null
+  let in_range = false
+  for (let char of charset) {
+    switch (char) {
+      case ",":
+        if (start !== null && end !== null) {
+          if (start!.charCodeAt(0) > end!.charCodeAt(0)) {
+            throw new Error("start > end of charset")
+          }
+          const len = end.charCodeAt(0) - start.charCodeAt(0) + 1
+          set.ranges.push({
+            start,
+            end,
+            len,
+          })
+          set.len += len
+          start = null
+          end = null
+          in_range = false
+        } else if (start !== null && !in_range) {
+          set.len += 1
+          set.ranges.push({ start, end: start, len: 1 })
+          start = null
+        } else if (start !== null && in_range) {
+          end = ","
+        } else if (start === null && end === null && !in_range) {
+          start = ","
+        } else {
+          throw new Error('unexpected ","')
+        }
+        break
+      case "-":
+        if (start === null) {
+          start = "-"
+        } else if (!in_range) {
+          in_range = true
+        } else if (in_range && end === null) {
+          end = "-"
+        } else {
+          throw new Error('unexpected "-"')
+        }
+        break
+      default:
+        if (start === null) {
+          start = char
+        } else if (in_range && end === null) {
+          end = char
+        } else {
+          throw new Error(`unexpected "${char}"`)
+        }
+    }
+  }
+  if (start !== null && end !== null) {
+    if (start!.charCodeAt(0) > end!.charCodeAt(0)) {
+      throw new Error("start > end of charset")
+    }
+    const len = end.charCodeAt(0) - start.charCodeAt(0) + 1
+    set.ranges.push({
+      start,
+      end,
+      len,
+    })
+    set.len += len
+  } else if (start !== null) {
+    set.len += 1
+    set.ranges.push({
+      start,
+      end: start,
+      len: 1,
+    })
+  }
+  return set
+}
+type CharSet = {
+  ranges: {
+    start: string
+    end: string
+    len: number
+  }[]
+  len: number
+}