0.1.5 Currency

libraries/Currency/README.md

@@ -8,7 +8,7 @@
 
 # Currency
 
-Arduino library to help formatting integers for printing as currency
+Arduino library to help formatting integers for printing as currency.
 
 ## Warning: experimental
 
@@ -23,7 +23,7 @@ The currency functions assume you do the currency math in integer units.
 For dollars and euro's this would be cents. For numbers with more decimals 
 it is a smaller unit. 
 
-Using integers makes addition, subtraction and multiplication exact.
+Using integers makes addition, subtraction and multiplication of currency exact.
 
 The library has experimental wrappers for float/double values. 
 Not tested extensively yet.
@@ -72,7 +72,9 @@ The following functions are implemented:
 
 ### float Wrapper functions
 
-Even more experimental - not tested
+Experimental - not tested
+
+All assumes 2 decimals except bitcoin which has 6.
 
 - **char \* bitcoinf(double value)**
 - **char \* dollarf(double value)**
@@ -85,17 +87,24 @@ Even more experimental - not tested
 
 ## Operation
 
-See examples
+See examples.
+
+
+## Performance
+
+Performance is hard to optimize. Most time is spend in splitting 
+individual digits (div / mod 10).
 
 
 ## Future
 
 - update documentation.
-- performance test + optimize.
 - More wrapper functions?
 - test double parameters.
+  - should decimals be a parameter too?
 - add BTC, USD, EUR, GBP, RUB, JPY, CNY, etc. (3+1 chars)
-- currency conversion?
-  - intern all in ???
 - https://www.easymarkets.com/eu/learn-centre/discover-trading/currency-acronyms-and-abbreviations/
 
+**won't**
+- currency conversion?
+  - intern all in ???

libraries/Currency/currency.h

@@ -3,7 +3,7 @@
 //
 //    FILE: currency.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.4
+// VERSION: 0.1.5
 // PURPOSE: Currency library for Arduino
 //     URL: https://github.com/RobTillaart/Currency
 
@@ -14,12 +14,13 @@
 //                      added pound, renamed roubles
 //  0.1.3   2021-12-14  update library.json, license, minor edits.
 //  0.1.4   2021-12-14  fix version number for PlatformIO
+//  0.1.5   2021-12-15  improve performance / size
 
 
 #include "Arduino.h"
 
 
-#define CURRENCY_VERSION                        (F("0.1.4"))
+#define CURRENCY_VERSION                        (F("0.1.5"))
 
 
 // TODO 
@@ -34,7 +35,7 @@
 char * currency(int32_t value, int decimals, char decimalSeparator, char thousandSeparator, char symbol)
 {
   static char tmp[16];
-  int index = 0;
+  uint8_t index = 0;
 
   int32_t v = value;
   bool negative = v < 0;
@@ -46,13 +47,11 @@ char * currency(int32_t value, int decimals, char decimalSeparator, char thousan
   {
     // separators
     if ((pos == 0) && (decimals > 0) ) tmp[index++] = decimalSeparator;
-    if ((pos > 0) && (pos % 3 == 0) && (v > 0)) tmp[index++] = thousandSeparator;
-
-    //  TODO can be optimized
-    int digit = (v % 10) + '0';
-    v /= 10;
-    tmp[index++] = digit;
+    if ((pos > 0)  && (pos % 3 == 0) ) tmp[index++] = thousandSeparator;
     pos++;
+
+    tmp[index++] = (v % 10) + '0';
+    v /= 10;
   }
   if (negative) tmp[index++] = '-';
   else          tmp[index++] = ' ';
@@ -60,12 +59,11 @@ char * currency(int32_t value, int decimals, char decimalSeparator, char thousan
   tmp[index]   = '\0';
 
   // reverse string
-  int length = strlen(tmp);                // optimize  index is strlen?
-  for (int i = 0; i < length / 2; i++)     // optimize   j--
+  for (uint8_t i = 0, j = index - 1; i < index / 2; i++, j--)
   {
     char c = tmp[i];
-    tmp[i] = tmp[length - i - 1];
-    tmp[length - i - 1] = c;
+    tmp[i] = tmp[j];
+    tmp[j] = c;
   }
   return tmp;
 }
@@ -86,12 +84,11 @@ char * currency64(int64_t value, int decimals, char decimalSeparator, char thous
   {
     // separators
     if ((pos == 0) && (decimals > 0) ) tmp[index++] = decimalSeparator;
-    if ((pos > 0) && (pos % 3 == 0) && (v > 0)) tmp[index++] = thousandSeparator;
-
-    int digit = (v % 10) + '0';
-    v /= 10;
-    tmp[index++] = digit;
+    if ((pos > 0)  && (pos % 3 == 0) ) tmp[index++] = thousandSeparator;
     pos++;
+
+    tmp[index++] = (v % 10) + '0';
+    v /= 10;
   }
   if (negative) tmp[index++] = '-';
   else          tmp[index++] = ' ';
@@ -99,12 +96,11 @@ char * currency64(int64_t value, int decimals, char decimalSeparator, char thous
   tmp[index]   = '\0';
 
   // reverse string
-  int length = strlen(tmp);
-  for (int i = 0; i < length / 2; i++)
+  for (uint8_t i = 0, j = index - 1; i < index / 2; i++, j--)
   {
     char c = tmp[i];
-    tmp[i] = tmp[length - i - 1];
-    tmp[length - i - 1] = c;
+    tmp[i] = tmp[j];
+    tmp[j] = c;
   }
   return tmp;
 }

libraries/Currency/examples/currency_performance/currency_performance.ino

@@ -2,7 +2,7 @@
 //    FILE: currency_performance.ino
 //  AUTHOR: Rob Tillaart
 // VERSION: 0.1.0
-// PURPOSE: performan
+// PURPOSE: performance test
 //    DATE: 2021-12-14
 //     URL: https://github.com/RobTillaart/currency
 

libraries/Currency/examples/currency_performance/performance_0.1.5.txt

@@ -0,0 +1,10 @@
+
+currency_performance.ino
+
+TIME: 436
+$ 10,000,000
+
+TIME: 2340
+$-9,999,999,999,999.99
+
+done...

libraries/Currency/examples/print_currency/print_currency.ino

@@ -1,10 +1,9 @@
 //
 //    FILE: print_currency.ino
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.0
-// PURPOSE: display an int as currency
+// PURPOSE: display an int as currency test
 //    DATE: 2021-02-28
-//     URL: https://github.com/RobTillaart/printFormatters
+//     URL: https://github.com/RobTillaart/currency
 
 
 #include "Arduino.h"

libraries/Currency/library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/currency"
   },
-  "version": "0.1.4",
+  "version": "0.1.5",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*",

libraries/Currency/library.properties

@@ -1,5 +1,5 @@
 name=currency
-version=0.1.4
+version=0.1.5
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library to help formatting integers as currency e.g. $ 1.000.000,00.