move string utility to `util.cc` + small script identifier fix

1 files changed, 102 insertions, 0 deletions

diff --git a/src/util.cc b/src/util.cc
index 30e1ba5..017e98b 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -41,6 +41,108 @@ void print(int Level, char *Text, ...){
 	}
 }
 
+// String Utility
+// =============================================================================
+bool isSpace(int c){
+	return c == ' '
+		|| c == '\t'
+		|| c == '\n'
+		|| c == '\r'
+		|| c == '\v'
+		|| c == '\f';
+}
+
+bool isAlpha(int c){
+	// TODO(fusion): This is most likely wrong! We're assuming a direct conversion
+	// from `char` to `int` which will cause sign extension for negative values. This
+	// wouldn't be a problem if we expected to parse only streams of `char[]` but can
+	// be problematic for the output of `getc` which returns bytes as `unsigned char`
+	// converted to `int`.
+	//	TLDR: The parameter `c` should be `uint8`.
+	return ('A' <= c && c <= 'Z')
+		|| ('a' <= c && c <= 'z')
+		|| c == -0x1C	// E4 => ä
+		|| c == -0x0A	// F6 => ö
+		|| c == -0x04	// FC => ü
+		|| c == -0x3C	// C4 => Ä
+		|| c == -0x2A	// D6 => Ö
+		|| c == -0x24	// DC => Ü
+		|| c == -0x21;	// DF => ß
+}
+
+bool isEngAlpha(int c){
+	return ('A' <= c && c <= 'Z')
+		|| ('a' <= c && c <= 'z');
+}
+
+bool isDigit(int c){
+	return ('0' <= c && c <= '9');
+}
+
+int toLower(int c){
+	// TODO(fusion): Same problem as `isAlpha`.
+	if(('A' <= c && c <= 'Z') || (0xC0 <= c && c <= 0xDE && c != 0xD7)){
+		c += 32;
+	}
+	return c;
+}
+
+int toUpper(int c){
+	// TODO(fusion): Same problem as `isAlpha`.
+	if(('A' <= c && c <= 'Z') || (0xE0 <= c && c <= 0xFE && c != 0xF7)){
+		c -= 32;
+	}
+	return c;
+}
+
+char *strLower(char *s){
+	for(int i = 0; s[i] != 0; i += 1){
+		s[i] = (char)toLower(s[i]);
+	}
+	return s;
+}
+
+char *strUpper(char *s){
+	for(int i = 0; s[i] != 0; i += 1){
+		s[i] = (char)toUpper(s[i]);
+	}
+	return s;
+}
+
+int stricmp(const char *s1, const char *s2, int Pos){
+	for(int i = 0; i < Pos; i += 1){
+		int c1 = toLower(s1[i]);
+		int c2 = toLower(s2[i]);
+		if(c1 > c2){
+			return 1;
+		}else if(c1 < c2){
+			return -1;
+		}else{
+			ASSERT(c1 == c2);
+			if(c1 == 0){
+				return 0;
+			}
+		}
+	}
+}
+
+char *findFirst(char *s, char c){
+	return strchr(s, (int)c);
+}
+
+char *findLast(char *s, char c){
+	char *Current = s;
+	char *Last = NULL;
+	while(true){
+		Current = strchr(Current, (int)c);
+		if(Current == NULL)
+			break;
+		Last = Current;
+		Current += 1; // skip character
+	}
+	return Last;
+}
+
 // TReadStream
 // =============================================================================
 bool TReadStream::readFlag(void){