feat: bracketed paste

README.md

@@ -70,6 +70,10 @@ fun main() {
 - `Mouse(MouseEvent)`: kind (`Down`, `Up`, `Drag`, `Move`, `ScrollUp`,
   `ScrollDown`), button, and a 1-based cell position. Call `mouse_on()`
   first.
+- `Paste(String)`: one whole bracketed paste, newlines normalized to
+  `\n`, so pasted text arrives as a single event instead of a stream of
+  keystrokes (and a pasted newline cannot act as Enter). Call
+  `paste_on()` first.
 - `Idle`: the timeout passed without input. This is what makes render
   loops tick.
 - `Closed`: stdin ended.
@@ -85,6 +89,7 @@ as `Ctrl("c")` like any other key: quitting is your program's decision.
   when stdin is not a terminal, so piped runs can bail out cleanly.
 - `alt_on() / alt_off()`: the alternate screen; scrollback survives.
 - `mouse_on() / mouse_off()`: SGR mouse reporting.
+- `paste_on() / paste_off()`: bracketed paste, delivered as `Paste` events.
 - `size() -> Size`: terminal width and height in cells, 80x24 fallback.
 - `write(s) / flush()`: straight to the terminal, no line buffering.
 - `read_event(timeout_ms) -> InputEvent`: see above.

ansi.rv

@@ -41,6 +41,16 @@ fun mouse_off() -> String {
     return "\u{1b}[?1006l\u{1b}[?1002l"
 }
 
+// Bracketed paste: the terminal wraps pasted text in ESC[200~ .. ESC[201~
+// instead of replaying it as keystrokes.
+fun paste_on() -> String {
+    return "\u{1b}[?2004h"
+}
+
+fun paste_off() -> String {
+    return "\u{1b}[?2004l"
+}
+
 // A Select Graphic Rendition sequence from raw code numbers, so callers can
 // compose styles without depending on any particular style type.
 fun sgr(codes: List<Int>) -> String {

input.rv

@@ -16,15 +16,25 @@ enum Step {
 
 struct Parser {
     buf: List<Int>,
+    // Bracketed paste: between ESC[200~ and ESC[201~ every byte is content,
+    // collected in `paste`; `tail` holds a partial match of the terminator.
+    pasting: Bool,
+    paste: List<Int>,
+    tail: List<Int>,
 }
 
 impl Parser {
     fun new() -> Parser {
         let b: List<Int> = []
-        return Parser { buf: b }
+        let p: List<Int> = []
+        let t: List<Int> = []
+        return Parser { buf: b, pasting: false, paste: p, tail: t }
     }
 
     fun feed(self, b: Int) -> Step {
+        if self.pasting {
+            return self._paste_feed(b)
+        }
         if self.buf.len() == 0 {
             return self._start(b)
         }
@@ -35,8 +45,13 @@ impl Parser {
     }
 
     // Settle a pending sequence after a read timeout. A lone ESC is the Esc
-    // key; any other partial sequence is dropped.
+    // key; any other partial sequence is dropped. Mid-paste, nothing settles:
+    // a large paste can span reads, so the content keeps accumulating until
+    // the terminator arrives.
     fun flush(self) -> InputEvent {
+        if self.pasting {
+            return InputEvent.Idle
+        }
         let lone_esc = self.buf.len() == 1 && self.buf[0] == 27
         self._clear()
         if lone_esc {
@@ -45,6 +60,61 @@ impl Parser {
         return InputEvent.Idle
     }
 
+    // One byte of paste content. The terminator ESC [ 2 0 1 ~ is matched
+    // incrementally through `tail`; on a mismatch the held bytes were real
+    // content, so they move into the paste before the byte is reconsidered.
+    fun _paste_feed(self, b: Int) -> Step {
+        let expected = _paste_end()
+        if b == expected[self.tail.len()] {
+            self.tail.push(b)
+            if self.tail.len() == expected.len() {
+                return Step.Ready(self._paste_done())
+            }
+            return Step.More
+        }
+        let held = self.tail
+        let fresh: List<Int> = []
+        self.tail = fresh
+        let i = 0
+        while i < held.len() {
+            self.paste.push(held[i])
+            i = i + 1
+        }
+        // The mismatched byte may itself start a terminator (its first byte
+        // cannot appear later inside one, so a single re-check suffices).
+        if b == expected[0] {
+            self.tail.push(b)
+            return Step.More
+        }
+        self.paste.push(b)
+        return Step.More
+    }
+
+    // The finished paste as one event, newlines normalized: terminals send
+    // \r (or \r\n) for line breaks in pasted text.
+    fun _paste_done(self) -> InputEvent {
+        let s = ""
+        let i = 0
+        while i < self.paste.len() {
+            let b = self.paste[i]
+            if b == 13 {
+                s = s.concat("\n")
+                if i + 1 < self.paste.len() && self.paste[i + 1] == 10 {
+                    i = i + 1
+                }
+            } else {
+                s = s.concat(byte_str(b))
+            }
+            i = i + 1
+        }
+        self.pasting = false
+        let p: List<Int> = []
+        self.paste = p
+        let t: List<Int> = []
+        self.tail = t
+        return InputEvent.Paste(s)
+    }
+
     fun _clear(self) {
         let empty: List<Int> = []
         self.buf = empty
@@ -105,6 +175,18 @@ impl Parser {
         if b >= 64 && b <= 126 {
             let params = self._params()
             self._clear()
+            if b == 126 {
+                let nums = _numbers(params)
+                if nums.len() > 0 && nums[0] == 200 {
+                    // Paste start: everything until ESC[201~ is content.
+                    self.pasting = true
+                    return Step.More
+                }
+                if nums.len() > 0 && nums[0] == 201 {
+                    // A stray paste end with no start; ignore it.
+                    return Step.More
+                }
+            }
             return Step.Ready(_decode_csi(params, b))
         }
         if b >= 32 && b <= 63 {
@@ -184,6 +266,11 @@ impl Parser {
     }
 }
 
+// The paste terminator byte sequence: ESC [ 2 0 1 ~.
+fun _paste_end() -> List<Int> {
+    return [27, 91, 50, 48, 49, 126]
+}
+
 // Total bytes in a UTF-8 character with this lead byte.
 fun _utf8_len(lead: Int) -> Int {
     if lead < 224 {

input_test.rv

@@ -27,6 +27,7 @@ fun event_tag(e: InputEvent) -> String {
     return match e {
         KeyPress(k) -> "key ${key_tag(k)}",
         Mouse(m) -> "mouse ${mouse_tag(m)}",
+        Paste(s) -> "paste:${s}",
         Idle -> "idle",
         Closed -> "closed",
     }
@@ -198,3 +199,49 @@ fun test_parser_reuse_across_events() {
     assert_eq_str(event_tag(feed_all(p, [98])), "key char:b")
     assert_eq_str(event_tag(feed_all(p, [27, 91, 60, 48, 59, 49, 59, 49, 77])), "mouse down b0 1,1")
 }
+
+// Bracketed paste: ESC[200~ starts, ESC[201~ ends, everything between is
+// content delivered as one Paste event.
+fun test_paste_arrives_as_one_event() {
+    // ESC[200~ h i ESC[201~
+    let bytes = [27, 91, 50, 48, 48, 126, 104, 105, 27, 91, 50, 48, 49, 126]
+    assert_eq_str(decode(bytes), "paste:hi")
+}
+
+fun test_paste_newlines_normalize_and_do_not_submit() {
+    // "a" CR "b" pastes as a\nb: the CR is content, not the Enter key.
+    let bytes = [27, 91, 50, 48, 48, 126, 97, 13, 98, 27, 91, 50, 48, 49, 126]
+    assert_eq_str(decode(bytes), "paste:a\nb")
+    // CRLF collapses to one newline.
+    let crlf = [27, 91, 50, 48, 48, 126, 97, 13, 10, 98, 27, 91, 50, 48, 49, 126]
+    assert_eq_str(decode(crlf), "paste:a\nb")
+}
+
+fun test_paste_keeps_a_partial_terminator_as_content() {
+    // An ESC then z inside the content: the held ESC flushes back into the
+    // paste when the match fails.
+    let bytes = [27, 91, 50, 48, 48, 126, 97, 27, 122, 98, 27, 91, 50, 48, 49, 126]
+    assert_eq_str(decode(bytes), "paste:a\u{1b}zb")
+}
+
+fun test_paste_carries_utf8_content() {
+    // é is 195 169.
+    let bytes = [27, 91, 50, 48, 48, 126, 195, 169, 27, 91, 50, 48, 49, 126]
+    assert_eq_str(decode(bytes), "paste:é")
+}
+
+fun test_paste_survives_a_flush_between_reads() {
+    let p = Parser.new()
+    let head = [27, 91, 50, 48, 48, 126, 104, 105]
+    assert_eq_str(event_tag(feed_all(p, head)), "idle")
+    // A read timeout mid-paste settles nothing and keeps the content.
+    assert_eq_str(event_tag(p.flush()), "idle")
+    let tail = [33, 27, 91, 50, 48, 49, 126]
+    assert_eq_str(event_tag(feed_all(p, tail)), "paste:hi!")
+}
+
+fun test_stray_paste_end_is_ignored() {
+    let p = Parser.new()
+    assert_eq_str(event_tag(feed_all(p, [27, 91, 50, 48, 49, 126])), "idle")
+    assert_eq_str(event_tag(feed_all(p, [113])), "key char:q")
+}

keys.rv

@@ -42,10 +42,13 @@ struct MouseEvent {
 }
 
 // What read_event hands back. Idle means the timeout passed with nothing
-// decoded; Closed means stdin ended.
+// decoded; Closed means stdin ended. Paste is one whole bracketed paste,
+// newlines normalized to \n, so a pasted block arrives as a single event
+// instead of a stream of keys (and its newlines cannot submit early).
 enum InputEvent {
     KeyPress(Key),
     Mouse(MouseEvent),
+    Paste(String),
     Idle,
     Closed,
 }

lib.rv

@@ -44,11 +44,12 @@ struct Terminal {
     raw: Bool,
     alt: Bool,
     mouse: Bool,
+    paste: Bool,
 }
 
 impl Terminal {
     fun new() -> Terminal {
-        return Terminal { parser: Parser.new(), raw: false, alt: false, mouse: false }
+        return Terminal { parser: Parser.new(), raw: false, alt: false, mouse: false, paste: false }
     }
 
     // Switch raw mode on. False when stdin is not a terminal, which is the
@@ -90,6 +91,18 @@ impl Terminal {
         self.mouse = false
     }
 
+    // Bracketed paste: pasted text arrives as one Paste event instead of a
+    // stream of keystrokes.
+    fun paste_on(self) {
+        self.write(ansi.paste_on())
+        self.paste = true
+    }
+
+    fun paste_off(self) {
+        self.write(ansi.paste_off())
+        self.paste = false
+    }
+
     // Current size, with an 80x24 fallback when stdout is not a terminal.
     fun size(self) -> Size {
         let w = term_cols()
@@ -159,6 +172,9 @@ impl Terminal {
 
     // Undo whatever setup and mouse_on switched on, in the right order.
     fun restore(self) {
+        if self.paste {
+            self.paste_off()
+        }
         if self.mouse {
             self.mouse_off()
         }

rv.toml

@@ -1,6 +1,6 @@
 [package]
 name = "perch"
-version = "0.1.0"
+version = "0.2.0"
 edition = "v2"
 
 [dependencies]

src/main.rv

@@ -48,6 +48,7 @@ fun main() {
         return
     }
     t.mouse_on()
+    t.paste_on()
     t.write("raw mode on: press keys or click, q or esc quits\r\n")
     let running = true
     while running {
@@ -75,6 +76,9 @@ fun main() {
             Mouse(m) -> {
                 t.write("${describe_mouse(m)}\r\n")
             },
+            Paste(s) -> {
+                t.write("paste (${s.length()} bytes)\r\n")
+            },
             Idle -> {},
             Closed -> {
                 running = false