Initial commit

1 files changed, 32 insertions, 0 deletions

diff --git a/src/main/kotlin/moe/nea/ledger/NumberUtil.kt b/src/main/kotlin/moe/nea/ledger/NumberUtil.kt
new file mode 100644
index 0000000..8aa9bb8
--- /dev/null
+++ b/src/main/kotlin/moe/nea/ledger/NumberUtil.kt
@@ -0,0 +1,32 @@
+package moe.nea.ledger
+
+import java.util.regex.Matcher
+import java.util.regex.Pattern
+
+// language=regexp
+val SHORT_NUMBER_PATTERN = "[0-9]+(?:,[0-9]+)*(?:\\.[0-9]+)?[kKmMbB]?"
+
+val siScalars = mapOf(
+    'k' to 1_000.0,
+    'K' to 1_000.0,
+    'm' to 1_000_000.0,
+    'M' to 1_000_000.0,
+    'b' to 1_000_000_000.0,
+    'B' to 1_000_000_000.0,
+)
+
+fun parseShortNumber(string: String): Double {
+    var k = string.replace(",", "")
+    val scalar = k.last()
+    var scalarMultiplier = siScalars[scalar]
+    if (scalarMultiplier == null) {
+        scalarMultiplier = 1.0
+    } else {
+        k = k.dropLast(1)
+    }
+    return k.toDouble() * scalarMultiplier
+}
+
+fun <T> Pattern.useMatcher(string: String, block: Matcher.() -> T): T? =
+    matcher(string).takeIf { it.matches() }?.let(block)
+