Add Uppercase & Lowercase functions

src/builtins.c

@@ -60,6 +60,8 @@
 {.name="ordinal",             .calltype=call, .argc=1, .args={string}, .returns=true, .rettype=number},
 {.name="character",           .calltype=call, .argc=1, .args={number}, .returns=true, .rettype=string},
 {.name="split",               .calltype=call, .argc=2, .args={string, string}, .returns=true, .rettype=list},
+{.name="uppercase",           .calltype=call, .argc=1, .args={string}, .returns=true, .rettype=string},
+{.name="lowercase",           .calltype=call, .argc=1, .args={string}, .returns=true, .rettype=string},
 {.name="floor",               .calltype=call, .argc=1, .args={number}, .returns=true, .rettype=number},
 {.name="round",               .calltype=call, .argc=1, .args={number}, .returns=true, .rettype=number},
 {.name="ceiling",             .calltype=call, .argc=1, .args={number}, .returns=true, .rettype=number},

src/runtime.h

@@ -1653,6 +1653,22 @@ static LIST ___split(STRING sep, STRING str)
 	return prev;
 }
 
+static STRING ___uppercase(STRING str)
+{
+    char* converted = gc_strdup(str);
+	for (char* c = converted; *c; c += mblen(str, MB_CUR_MAX))
+	    *c = toupper(*c);
+    return converted;
+}
+
+static STRING ___lowercase(STRING str)
+{
+    char* converted = gc_strdup(str);
+	for (char* c = converted; *c; c += mblen(str, MB_CUR_MAX))
+	    *c = tolower(*c);
+    return converted;
+}
+
 /*
 static BLOCK ___remember(BLOCK b)
 {

tests/strings.cog

@@ -41,4 +41,16 @@ else
 Print If == List ("Hello" "world!") Split on " " with "Hello world!"
 	"PASS: Splitting a string"
 else
-	"FAIL: Splitting a string"
+	"FAIL: Splitting a string";
+
+~~ TODO: Only ASCII conversions are supported right now.
+~~ Print If == "123 áæćde" Lowercase "123 ÁÆĆdE"
+Print If == "123 ♥ æabcde" Lowercase "123 ♥ æAbCdE"
+	"PASS: Converting a string to lowercase"
+else
+	"FAIL: Converting a string to lowercase";
+
+Print If == "123 ♥ ÆABCDE" Uppercase "123 ♥ ÆaBcde"
+	"PASS: Converting a string to uppercase"
+else
+	"FAIL: Converting a string to uppercase";