String Streams

In-memory streams let you use the same Text / Byte APIs without touching the filesystem — handy for tests, parsing buffers you already hold, and building text before a single print or send.

Reading a String as text

// ( s:String -- r true | err:s false )
TextReader.newFromString^

: printRunes ( s:String -- )
  TextReader.newFromString^ drop >ts
  t:peek foreach
    i r>s $
  /foreach
  t:.close^
  t:drop
;
"αβ\nγ" printRunes

For line-oriented work, keep the reader on ts and call .readLine^ in a loop (same pattern as File Streams).

Newlines in the source String are ordinary runes (\n, and \r if present). readLine still treats \n as the line terminator and strips a preceding \r.

Writing text in memory: StringBuilder

StringBuilder is a TextWrite — the same write-shaped members as other text writers:

StringBuilder.new^ >ts
"hello" t:.writeString^
32 t:.writeRune^
"world" t:.writeLine^
t:.toString^ $              // hello world\n
t:drop

You already saw this style under Methods. Pretty / indented builders (newWithPretty, nesting helpers) are for structured rendering (for example Json); the plain builder is enough for most stream-like accumulation.

Bytes in memory: ByteList

ByteList is the buffer type for byte streams — a strongly typed list of unsigned 8-bit values (Numeric Lists).

ByteList.new^ >xs
x:peek ByteWriter.newFromBytes^ drop >ts
72 t:.writeNextByte^        // 'H'
105 t:.writeNextByte^       // 'i'
t:.flush^
t:.close^
t:drop

x:peek ByteReader.newFromBytes^ drop >ts
2 t:.readBytes^ >ys
y:.len@ $ nl                // 2
y:drop
t:.close^
t:drop
x:drop

The writer appends to the list you passed in; it does not replace earlier contents. The reader walks from the start of the list with its own offset — it does not remove items from the ByteList.