6456 - new directory for live-blogging prototypes

I don't have layers yet in Mu. But I can still create lots of versions
of a program.

1 files changed, 188 insertions, 0 deletions

diff --git a/prototypes/browse/16-screen-state-broken.mu b/prototypes/browse/16-screen-state-broken.mu
new file mode 100644
index 00000000..d80d8375
--- /dev/null
+++ b/prototypes/browse/16-screen-state-broken.mu
@@ -0,0 +1,188 @@
+# Incomplete second attempt at parsing headings.
+#
+# This 'OO' approach seems more scalable. We hoist out all the outer framework
+# for deciding when to increment 'col', when to increment 'row' and when to
+# start a new page in a whole new part of the screen. Now it gets encapsulated
+# into a series of small helpers that can be called from multiple places.
+# Objects as coroutines.
+#
+# In spite of these advances, I need to first wrestle with a parsing issue.
+# This text has a heading:
+#
+#   abc *def
+#   # ghi*
+#
+# Ugh, so I can't do this translation in a single pass. At the first asterisk
+# there's just not enough information to know whether it starts a bold text or
+# not.
+#
+# Then again, maybe I should just keep going and not try to be compatible with
+# GitHub-Flavored Markdown. Require that new headings are also new paragraphs.
+
+fn main args: (addr array (addr array byte)) -> exit-status/ebx: int {
+  var filename/eax: (addr array byte) <- first-arg args
+  var file/esi: (addr buffered-file) <- load-file filename
+  enable-screen-grid-mode
+  enable-keyboard-immediate-mode
+  var nrows/eax: int <- copy 0
+  var ncols/ecx: int <- copy 0
+  nrows, ncols <- screen-size
+  var screen-position-state-storage: screen-position-state
+  var screen-position-state: (addr screen-position-state) = address screen-position-state-storage
+  init-screen-position-state screen-position-state, nrows, ncols
+  {
+    render file, screen-position-state
+    var key/eax: byte <- read-key
+    compare key, 0x71  # 'q'
+    loop-if-!=
+  }
+  enable-keyboard-type-mode
+  enable-screen-type-mode
+  exit-status <- copy 0
+}
+
+type screen-position-state {
+  nrows: int  # const
+  ncols: int  # const
+  toprow: int
+  botrow: int
+  leftcol: int
+  rightcol: int
+  row: int
+  col: int
+}
+
+fn render in: (addr buffered-file), state: (addr screen-position-state) {
+  start-drawing state
+  render-normal in, state
+}
+
+fn render-normal in: (addr buffered-file), state: (addr screen-position-state) {
+  {
+    # if done-drawing?(state) break
+    var done?/eax: boolean <- done-drawing? state
+    compare done?, 0
+    break-if-!=
+    #
+    var c/eax: byte <- read-byte-buffered in
+    # if (c == EOF) break
+    compare c, 0xffffffff  # EOF marker
+    break-if-=
+    # if (c == '*') start-bold, render-until-asterisk(in, state), reset
+    # else if (c == '_') start-bold, render-until-underscore(in, state), reset
+    # else if (c == '#') compute-color, start color, render-header-line(in, state), reset
+    # else add-char(state, c)
+  }
+}
+
+fn render-until-asterisk in: (addr buffered-file), state: (addr screen-position-state) {
+  {
+    # if done-drawing?(state) break
+    var done?/eax: boolean <- done-drawing? state
+    compare done?, 0
+    break-if-!=
+    #
+    var c/eax: byte <- read-byte-buffered in
+    # if (c == EOF) break
+    compare c, 0xffffffff  # EOF marker
+    break-if-=
+    # if (c == '*') break
+    # else add-char(state, c)
+  }
+}
+
+fn render-until-underscore in: (addr buffered-file), state: (addr screen-position-state) {
+  {
+    # if done-drawing?(state) break
+    var done?/eax: boolean <- done-drawing? state
+    compare done?, 0
+    break-if-!=
+    #
+    var c/eax: byte <- read-byte-buffered in
+    # if (c == EOF) break
+    compare c, 0xffffffff  # EOF marker
+    break-if-=
+    # if (c == '_') break
+    # else add-char(state, c)
+  }
+}
+
+fn render-header-line in: (addr buffered-file), state: (addr screen-position-state) {
+  {
+    # if done-drawing?(state) break
+    var done?/eax: boolean <- done-drawing? state
+    compare done?, 0
+    break-if-!=
+    #
+    var c/eax: byte <- read-byte-buffered in
+    # if (c == EOF) break
+    compare c, 0xffffffff  # EOF marker
+    break-if-=
+    # if (c == '*') break
+    # else add-char(state, c)
+  }
+}
+
+fn init-screen-position-state self: (addr screen-position-state), nrows: int, ncols: int {
+  # hardcoded parameters:
+  #   top-margin
+  #   page-margin
+  #   text-width
+  var dest/eax: (addr int) <- copy 0
+  # self->nrows = nrows
+  # self->ncols = ncols
+  # self->toprow = top-margin
+  # self->botrow = nrows
+  # self->leftcol = page-margin
+  # self->rightcol = self->leftcol + text-width
+  # start-drawing(self)
+}
+
+fn start-drawing self: (addr screen-position-state) {
+  # self->row = toprow
+  # self->col = leftcol
+}
+
+fn add-char self: (addr screen-position-state), c: byte {
+  # print c
+  # self->col++
+  # if (self->col > self->rightcol) next-line(self)
+}
+
+fn next-line self: (addr screen-position-state) {
+  # self->row++
+  # if (self->row > self->botrow) next-page(self)
+}
+
+fn next-page self: (addr screen-position-state) {
+  # self->leftcol = self->rightcol + 5
+  # self->rightcol = self->leftcol + text-width
+}
+
+fn done-drawing? self: (addr screen-position-state) -> result/eax: boolean {
+  # self->rightcol >= self->ncols
+}
+
+fn first-arg args-on-stack: (addr array (addr array byte)) -> out/eax: (addr array byte) {
+  var args/eax: (addr array (addr array byte)) <- copy args-on-stack
+  var result/eax: (addr addr array byte) <- index args, 1
+  out <- copy *result
+}
+
+fn load-file filename: (addr array byte) -> out/esi: (addr buffered-file) {
+  var result: (handle buffered-file)
+  {
+    var tmp1/eax: (addr handle buffered-file) <- address result
+    open filename, 0, tmp1
+  }
+  var tmp2/eax: (addr buffered-file) <- lookup result
+  out <- copy tmp2
+}
+
+fn dump in: (addr buffered-file) {
+  var c/eax: byte <- read-byte-buffered in
+  compare c, 0xffffffff  # EOF marker
+  break-if-=
+  print-byte c
+  loop
+}