Data update

Task/Binary-strings/M2000-Interpreter/binary-strings.m2000

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+' String assignment
+a$="alfa"
+string a="beta"
+b="beta too"
+all=a$+a+b
+Print All
+' String comparison
+Print a$=a, a=b, a+A+" too"+a$=a+b+a$  ' false false true
+b$=a$
+// compare return 0 for equal (-1,0, 1),
+//same as <=> but compare work with variables only (without coping values)
+print "using compare", compare(a$, b$), a$<=>b$  ' 0 0
+' String cloning and copying
+a2$=a$ ' copy
+' Check if a string is empty
+print a2$="", len(a$)=0
+' Append a byte to a string
+c$=Str$("ABCDE")  ' utf16le "ABCDE" convert to ANSI (one byte per code)
+Print len(c$)=2.5  ' measure 16bit, so we get 2.5x2=5 bytes
+c$+=Str$("Z")
+Print Len(c$)=3
+Print chr$(c$)="ABCDEZ"  ' convert to UTF16LE and then compare
+' Extract a substring from a string
+Print chr$(mid$(c$,2, 2 as byte))="BC"
+Print mid$("ABCDEZ",2,2) ="BC"
+' Replace every occurrence of a byte (or a string) in a string with another string
+Print Replace$("BC", "?", "ABCDEZBC")="A?DEZ?"
+Print Replace$("BC", "?", CHR$(c$))="A?DEZ"
+' String creation and destruction (using buffers. Memory Blocks)
+' (when needed and if there's no garbage collection or similar mechanism)
+'Join strings (IN A BUFFRT)
+buffer clear K as byte*10  ' using clear to erase the buffer with 0
+Return K, 0:=c$
+Print eval(k, 2)=asc("C"), eval(k, 3)=asc("D")
+Return k, 2:=str$("KL")
+Print chr$(eval$(k, 0, 6))="ABKLEZ"
+' rotate one byte
+M=	eval(K,0)
+return k, 0:=eval$(k, 1, 5), 5:=m    ' we can place strings or bytes at specific index - from 0.
+Print chr$(eval$(k, 0, 6))="BKLEZA"    ' true
+// change length of buffer
+buffer K as byte*6
+// now we get the full string (with the length of 6 bytes)
+Print chr$(eval$(k))="BKLEZA"   ' true
+buffer K1 as byte*6
+// buffers are special objects, so we have strings refering by object pointer.
+// we can pass the buffer pointer or return it from a function, also we can swap variables for buffers
+swap K, k1
+Print chr$(eval$(k1))="BKLEZA"   ' true
+// we can get the address of string:
+Print k1(0)  ' return the absolute address of byte at offset 0 on k1 buffer