⚡ add to_num & to_char in std.string

doc/benchmark.md

@@ -111,14 +111,9 @@ In 2022/2/17 update we added `\e` into the lexer. And the `bfcolored.nas` uses t
 
 ![mandelbrot](../doc/pic/mandelbrot.png)
 
-## More nasal generated pictures
+## More Nasal Generated Pictures
 
-![mandelbrotset](../doc/pic/mandelbrotset.png)
+|Mandelbrot Set|Mandelbrot Set|Burning Ship|Burning Ship|Feigenbaum|
-
+|:----:|:----:|:----:|:----:|:----:|
-![mandelbrotset_reverse](../doc/pic/mandelbrotset_reverse.png)
+|[mandelbrotset.nas](../test/mandelbrotset.nas)|[mandelbrotset.nas](../test/mandelbrotset.nas)|[burningship.nas](../test/burningship.nas)|[burningship.nas](../test/burningship.nas)|[feigenbaum.nas](../test/feigenbaum.nas)|
-
+|![mandelbrotset](../doc/pic/mandelbrotset.png)|![mandelbrotset_reverse](../doc/pic/mandelbrotset_reverse.png)|![burningship](../doc/pic/burningship.png)|![burningship_reverse](../doc/pic/burningship_reverse.png)|![feigenbaum](../doc/pic/feigenbaum.png)|
-![burningship](../doc/pic/burningship.png)
-
-![burningship_reverse](../doc/pic/burningship_reverse.png)
-
-![feigenbaum](../doc/pic/feigenbaum.png)

std/lib.nas

@@ -1,7 +1,6 @@
 # lib.nas
 # 2019 ValKmjolnir
 use std.math;
-use std.string;
 use std.io;
 use std.os;
 use std.unix;

std/string.nas

@@ -10,3 +10,32 @@ var join = func(sep, vec) {
     }
     return res;
 }
+
+var __temp_char = func(number) {
+    return __char(number);
+}
+
+var __temp_append = func(vec, elem...) {
+    return __append(vec, elem);
+}
+
+var __temp_contains = func(hash, key) {
+    return __contains(hash, key);
+}
+
+var __num_to_char = [];
+var __char_to_num = {};
+func() {
+    for(var i = 0; i<256; i += 1) {
+        __temp_append(__num_to_char, __temp_char(i));
+        __char_to_num[__temp_char(i)] = i;
+    }
+}();
+
+var to_char = func(number) {
+    return 0<=number and number<256? __num_to_char[number]:"";
+}
+
+var to_num = func(character) {
+    return __temp_contains(__char_to_num, character)? __char_to_num[character]:-1;
+}