read string literals into a dynamically resized transient buffer

startup.4th

@@ -1734,19 +1734,29 @@ CREATE TIB-LEFTOVER-BYTES 0 ,
       ENDCASE
    THEN ;
 
+2VARIABLE STRING-BUFFER
+0 0 STRING-BUFFER 2!
+
 \ Read a literal character string up to the next double-quote character
-\ Unlike WORD the string is stored in contiguous *allocated* data space
+\ The string is stored in a transient buffer and will become invalid when
+\ the next string is read; both the address and content may change
 \ The delimiting double-quote character is removed from the input buffer
 \ Double-quote and backslash characters can be escaped with a backslash
 : READSTRING ( "ccc<doublequote>" -- c-addr u )
-   HERE
+   STRING-BUFFER 2@ 0
+   ( S: addr length index )
    BEGIN
       PEEK-CHAR [CHAR] " <>
    WHILE
-      ESCAPED-CHAR C,
+      2DUP <= IF
+         \ Grow the buffer by at least 50% + 16 bytes
+         \ Store the actual allocated object size, not the requested size
+         -ROT DUP 2/ + 16 + RESIZE DUP OBJECT-SIZE
+         2DUP STRING-BUFFER 2! ROT
+      THEN
+      ROT 2DUP + ESCAPED-CHAR SWAP C! -ROT 1+
    REPEAT
-   SKIP-CHAR
-   HERE OVER - ;
+   SKIP-CHAR NIP ;
 
 : PARSENUMBER ( c-addr u -- n TRUE | c-addr u FALSE )
    DUP 0= IF FALSE EXIT THEN
@@ -1776,12 +1786,11 @@ CREATE TIB-LEFTOVER-BYTES 0 ,
    WHILE
       PEEK-CHAR [CHAR] " = IF
          SKIP-CHAR
+         READSTRING
          STATE @ IF
             POSTPONE LITSTRING
-            HERE 0 C,
-            READSTRING NIP SWAP C! ALIGN
-         ELSE
-            READSTRING
+            255 UMIN DUP C,
+            HERE SWAP DUP ALLOT CMOVE ALIGN
          THEN
       ELSE
          WORD