7842 - new directory organization

Baremetal is now the default build target and therefore has its sources
at the top-level. Baremetal programs build using the phase-2 Mu toolchain
that requires a Linux kernel. This phase-2 codebase which used to be at
the top-level is now under the linux/ directory. Finally, the phase-2 toolchain,
while self-hosting, has a way to bootstrap from a C implementation, which
is now stored in linux/bootstrap. The bootstrap C implementation uses some
literate programming tools that are now in linux/bootstrap/tools.

So the whole thing has gotten inverted. Each directory should build one
artifact and include the main sources (along with standard library). Tools
used for building it are relegated to sub-directories, even though those
tools are often useful in their own right, and have had lots of interesting
programs written using them.

A couple of things have gotten dropped in this process:
  - I had old ways to run on just a Linux kernel, or with a Soso kernel.
    No more.
  - I had some old tooling for running a single test at the cursor. I haven't
    used that lately. Maybe I'll bring it back one day.

The reorg isn't done yet. Still to do:
  - redo documentation everywhere. All the README files, all other markdown,
    particularly vocabulary.md.
  - clean up how-to-run comments at the start of programs everywhere
  - rethink what to do with the html/ directory. Do we even want to keep
    supporting it?

In spite of these shortcomings, all the scripts at the top-level, linux/
and linux/bootstrap are working. The names of the scripts also feel reasonable.
This is a good milestone to take stock at.

1 files changed, 280 insertions, 0 deletions

diff --git a/shell/grapheme-stack.mu b/shell/grapheme-stack.mu
new file mode 100644
index 00000000..456df0cb
--- /dev/null
+++ b/shell/grapheme-stack.mu
@@ -0,0 +1,280 @@
+# grapheme stacks are the smallest unit of editable text
+
+type grapheme-stack {
+  data: (handle array grapheme)
+  top: int
+}
+
+fn initialize-grapheme-stack _self: (addr grapheme-stack), n: int {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var d/edi: (addr handle array grapheme) <- get self, data
+  populate d, n
+  var top/eax: (addr int) <- get self, top
+  copy-to *top, 0
+}
+
+fn clear-grapheme-stack _self: (addr grapheme-stack) {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var top/eax: (addr int) <- get self, top
+  copy-to *top, 0
+}
+
+fn grapheme-stack-empty? _self: (addr grapheme-stack) -> _/eax: boolean {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var top/eax: (addr int) <- get self, top
+  compare *top, 0
+  {
+    break-if-!=
+    return 1/true
+  }
+  return 0/false
+}
+
+fn grapheme-stack-length _self: (addr grapheme-stack) -> _/eax: int {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var top/eax: (addr int) <- get self, top
+  return *top
+}
+
+fn push-grapheme-stack _self: (addr grapheme-stack), _val: grapheme {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var top-addr/ecx: (addr int) <- get self, top
+  var data-ah/edx: (addr handle array grapheme) <- get self, data
+  var data/eax: (addr array grapheme) <- lookup *data-ah
+  var top/edx: int <- copy *top-addr
+  var dest-addr/edx: (addr grapheme) <- index data, top
+  var val/eax: grapheme <- copy _val
+  copy-to *dest-addr, val
+  add-to *top-addr, 1
+}
+
+fn pop-grapheme-stack _self: (addr grapheme-stack) -> _/eax: grapheme {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var top-addr/ecx: (addr int) <- get self, top
+  {
+    compare *top-addr, 0
+    break-if->
+    return -1
+  }
+  subtract-from *top-addr, 1
+  var data-ah/edx: (addr handle array grapheme) <- get self, data
+  var data/eax: (addr array grapheme) <- lookup *data-ah
+  var top/edx: int <- copy *top-addr
+  var result-addr/eax: (addr grapheme) <- index data, top
+  return *result-addr
+}
+
+fn copy-grapheme-stack _src: (addr grapheme-stack), dest: (addr grapheme-stack) {
+  var src/esi: (addr grapheme-stack) <- copy _src
+  var data-ah/edi: (addr handle array grapheme) <- get src, data
+  var _data/eax: (addr array grapheme) <- lookup *data-ah
+  var data/edi: (addr array grapheme) <- copy _data
+  var top-addr/ecx: (addr int) <- get src, top
+  var i/eax: int <- copy 0
+  {
+    compare i, *top-addr
+    break-if->=
+    var g/edx: (addr grapheme) <- index data, i
+    push-grapheme-stack dest, *g
+    i <- increment
+    loop
+  }
+}
+
+# dump stack to screen from bottom to top
+# colors hardcoded
+fn render-stack-from-bottom-wrapping-right-then-down screen: (addr screen), _self: (addr grapheme-stack), xmin: int, ymin: int, xmax: int, ymax: int, _x: int, _y: int -> _/eax: int, _/ecx: int {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var data-ah/edi: (addr handle array grapheme) <- get self, data
+  var _data/eax: (addr array grapheme) <- lookup *data-ah
+  var data/edi: (addr array grapheme) <- copy _data
+  var x/eax: int <- copy _x
+  var y/ecx: int <- copy _y
+  var top-addr/edx: (addr int) <- get self, top
+  var i/ebx: int <- copy 0
+  {
+    compare i, *top-addr
+    break-if->=
+    {
+      var g/edx: (addr grapheme) <- index data, i
+      x, y <- render-grapheme screen, *g, xmin, ymin, xmax, ymax, x, y, 3/fg=cyan, 0/bg
+    }
+    i <- increment
+    loop
+  }
+  return x, y
+}
+
+# helper for small words
+fn render-stack-from-bottom screen: (addr screen), self: (addr grapheme-stack), x: int, y: int -> _/eax: int {
+  var _width/eax: int <- copy 0
+  var _height/ecx: int <- copy 0
+  _width, _height <- screen-size screen
+  var width/edx: int <- copy _width
+  var height/ebx: int <- copy _height
+  var x2/eax: int <- copy 0
+  var y2/ecx: int <- copy 0
+  x2, y2 <- render-stack-from-bottom-wrapping-right-then-down screen, self, x, y, width, height, x, y
+  return x2  # y2? yolo
+}
+
+# dump stack to screen from top to bottom
+# optionally render a 'cursor' with the top grapheme
+fn render-stack-from-top-wrapping-right-then-down screen: (addr screen), _self: (addr grapheme-stack), xmin: int, ymin: int, xmax: int, ymax: int, _x: int, _y: int, render-cursor?: boolean -> _/eax: int, _/ecx: int {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var data-ah/edi: (addr handle array grapheme) <- get self, data
+  var _data/eax: (addr array grapheme) <- lookup *data-ah
+  var data/edi: (addr array grapheme) <- copy _data
+  var x/eax: int <- copy _x
+  var y/ecx: int <- copy _y
+  var top-addr/edx: (addr int) <- get self, top
+  var i/ebx: int <- copy *top-addr
+  i <- decrement
+  # if render-cursor?, peel off first iteration
+  {
+    compare render-cursor?, 0/false
+    break-if-=
+    compare i, 0
+    break-if-<
+    {
+      var g/edx: (addr grapheme) <- index data, i
+      x, y <- render-grapheme screen, *g, xmin, ymin, xmax, ymax, x, y, 3/fg=cyan, 7/bg=cursor
+    }
+    i <- decrement
+  }
+  # remaining iterations
+  {
+    compare i, 0
+    break-if-<
+    {
+      var g/edx: (addr grapheme) <- index data, i
+      x, y <- render-grapheme screen, *g, xmin, ymin, xmax, ymax, x, y, 3/fg=cyan, 0/bg=cursor
+    }
+    i <- decrement
+    loop
+  }
+  return x, y
+}
+
+# helper for small words
+fn render-stack-from-top screen: (addr screen), self: (addr grapheme-stack), x: int, y: int, render-cursor?: boolean -> _/eax: int {
+  var _width/eax: int <- copy 0
+  var _height/ecx: int <- copy 0
+  _width, _height <- screen-size screen
+  var width/edx: int <- copy _width
+  var height/ebx: int <- copy _height
+  var x2/eax: int <- copy 0
+  var y2/ecx: int <- copy 0
+  x2, y2 <- render-stack-from-top-wrapping-right-then-down screen, self, x, y, width, height, x, y, render-cursor?
+  return x2  # y2? yolo
+}
+
+fn test-render-grapheme-stack {
+  # setup: gs = "abc"
+  var gs-storage: grapheme-stack
+  var gs/edi: (addr grapheme-stack) <- address gs-storage
+  initialize-grapheme-stack gs, 5
+  var g/eax: grapheme <- copy 0x61/a
+  push-grapheme-stack gs, g
+  g <- copy 0x62/b
+  push-grapheme-stack gs, g
+  g <- copy 0x63/c
+  push-grapheme-stack gs, g
+  # setup: screen
+  var screen-on-stack: screen
+  var screen/esi: (addr screen) <- address screen-on-stack
+  initialize-screen screen, 5, 4
+  #
+  var x/eax: int <- render-stack-from-bottom screen, gs, 0/x, 0/y
+  check-screen-row screen, 0/y, "abc ", "F - test-render-grapheme-stack from bottom"
+  check-ints-equal x, 3, "F - test-render-grapheme-stack from bottom: result"
+  check-background-color-in-screen-row screen, 7/bg=cursor, 0/y, "   ", "F - test-render-grapheme-stack from bottom: bg"
+  #
+  var x/eax: int <- render-stack-from-top screen, gs, 0/x, 1/y, 0/cursor=false
+  check-screen-row screen, 1/y, "cba ", "F - test-render-grapheme-stack from top without cursor"
+  check-ints-equal x, 3, "F - test-render-grapheme-stack from top without cursor: result"
+  check-background-color-in-screen-row screen, 7/bg=cursor, 1/y, "   ", "F - test-render-grapheme-stack from top without cursor: bg"
+  #
+  var x/eax: int <- render-stack-from-top screen, gs, 0/x, 2/y, 1/cursor=true
+  check-screen-row screen, 2/y, "cba ", "F - test-render-grapheme-stack from top with cursor"
+  check-ints-equal x, 3, "F - test-render-grapheme-stack from top without cursor: result"
+  check-background-color-in-screen-row screen, 7/bg=cursor, 2/y, "|   ", "F - test-render-grapheme-stack from top with cursor: bg"
+}
+
+# compare from bottom
+# beware: modifies 'stream', which must be disposed of after a false result
+fn prefix-match? _self: (addr grapheme-stack), s: (addr stream byte) -> _/eax: boolean {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var data-ah/edi: (addr handle array grapheme) <- get self, data
+  var _data/eax: (addr array grapheme) <- lookup *data-ah
+  var data/edi: (addr array grapheme) <- copy _data
+  var top-addr/ecx: (addr int) <- get self, top
+  var i/ebx: int <- copy 0
+  {
+    compare i, *top-addr
+    break-if->=
+    # if curr != expected, return false
+    {
+      var curr-a/edx: (addr grapheme) <- index data, i
+      var expected/eax: grapheme <- read-grapheme s
+      {
+        compare expected, *curr-a
+        break-if-=
+        return 0/false
+      }
+    }
+    i <- increment
+    loop
+  }
+  return 1   # true
+}
+
+# compare from bottom
+# beware: modifies 'stream', which must be disposed of after a false result
+fn suffix-match? _self: (addr grapheme-stack), s: (addr stream byte) -> _/eax: boolean {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var data-ah/edi: (addr handle array grapheme) <- get self, data
+  var _data/eax: (addr array grapheme) <- lookup *data-ah
+  var data/edi: (addr array grapheme) <- copy _data
+  var top-addr/eax: (addr int) <- get self, top
+  var i/ebx: int <- copy *top-addr
+  i <- decrement
+  {
+    compare i, 0
+    break-if-<
+    {
+      var curr-a/edx: (addr grapheme) <- index data, i
+      var expected/eax: grapheme <- read-grapheme s
+      # if curr != expected, return false
+      {
+        compare expected, *curr-a
+        break-if-=
+        return 0/false
+      }
+    }
+    i <- decrement
+    loop
+  }
+  return 1   # true
+}
+
+fn grapheme-stack-is-decimal-integer? _self: (addr grapheme-stack) -> _/eax: boolean {
+  var self/esi: (addr grapheme-stack) <- copy _self
+  var data-ah/eax: (addr handle array grapheme) <- get self, data
+  var _data/eax: (addr array grapheme) <- lookup *data-ah
+  var data/edx: (addr array grapheme) <- copy _data
+  var top-addr/ecx: (addr int) <- get self, top
+  var i/ebx: int <- copy 0
+  var result/eax: boolean <- copy 1/true
+  $grapheme-stack-is-integer?:loop: {
+    compare i, *top-addr
+    break-if->=
+    var g/edx: (addr grapheme) <- index data, i
+    result <- is-decimal-digit? *g
+    compare result, 0/false
+    break-if-=
+    i <- increment
+    loop
+  }
+  return result
+}