Add nvim-ts article

14 files changed, 454 insertions, 12 deletions

diff --git a/src/blog/index.gsp b/src/blog/index.gsp
new file mode 100644
index 0000000..4d4aab8
--- /dev/null
+++ b/src/blog/index.gsp
@@ -0,0 +1,44 @@
+html lang="en" {
+	head { HEAD }
+	body {
+		header {
+			div .head {
+				h1 {-Blog Posts}
+				INCLUDE(nav.gsp)
+			}
+
+			figure .quote {
+				blockquote {
+					p {=
+						Object-oriented programming is an exceptionally bad idea which could
+						only have originated in California.
+					}
+				}
+				figcaption {-Edsgar W. Dijkstra}
+			}
+		}
+
+		main {
+			p {=
+				On this section of the site you will find my blog.  Most of what I post
+				here is related to software-development and -design, although maybe
+				you’ll find something unrelated on here too.
+			}
+
+			p {-Posts:}
+
+			ul {
+				m4_dnl ARTICLE(grab, {-Making Grep Better})
+				m4_dnl ARTICLE(andy-val, {-Values in Andy})
+				m4_dnl ARTICLE(new-sh, {-Making a New Shell})
+				m4_dnl ARTICLE(extend, {-Extensible Scripting})
+				m4_dnl ARTICLE(gsp, {-Writing an HTML Preprocessor (feat. Tree-Sitter)})
+				m4_dnl ARTICLE(fw-ec, {-Patching My Laptop’s Embedded Controller})
+
+				ARTICLE(nvim-ts, {-Hacking with Tree-Sitter on Neovim})
+			}
+		}
+
+		footer { FOOT }
+	}
+}
diff --git a/src/blog/nvim-ts/change-command.diff b/src/blog/nvim-ts/change-command.diff
new file mode 100644
index 0000000..43bcdf9
--- /dev/null
+++ b/src/blog/nvim-ts/change-command.diff
@@ -0,0 +1,9 @@
+ 		end
+ 
+ 		if node ~= nil then
+-			-- TODO
++			local sr, sc, er, ec = node:child(0):range()
++			vim.api.nvim_buf_set_text(0, sr, sc, er, ec, { rhs })
+ 		end
+ 	end, {
+ 		buffer = true,
diff --git a/src/blog/nvim-ts/final.lua b/src/blog/nvim-ts/final.lua
new file mode 100644
index 0000000..948ee30
--- /dev/null
+++ b/src/blog/nvim-ts/final.lua
@@ -0,0 +1,28 @@
+local ts_utils = require('nvim-treesitter.ts_utils')
+
+local function map(lhs, rhs)
+	vim.keymap.set('n', lhs, function()
+		local node = ts_utils.get_node_at_cursor()
+		if node == nil then
+			error('No tree-sitter parser found.')
+		end
+
+		while node ~= nil and node:type() ~= 'operation' do
+			node = node:parent()
+		end
+
+		if node ~= nil then
+			local sr, sc, er, ec = node:child(0):range()
+			vim.api.nvim_buf_set_text(0, sr, sc, er, ec, { rhs })
+		end
+	end, {
+		buffer = true,
+		noremap = true,
+		silent = true,
+	})
+end
+
+map('p', 'pick')
+map('r', 'reword')
+map('s', 'squash')
+map('f', 'fixup')
diff --git a/src/blog/nvim-ts/final.webm b/src/blog/nvim-ts/final.webm
new file mode 100644
index 0000000..cbe2c55
--- /dev/null
+++ b/src/blog/nvim-ts/final.webm
diff --git a/src/blog/nvim-ts/get-cursor.diff b/src/blog/nvim-ts/get-cursor.diff
new file mode 100644
index 0000000..3e34afc
--- /dev/null
+++ b/src/blog/nvim-ts/get-cursor.diff
@@ -0,0 +1,12 @@
++local ts_utils = require('nvim-treesitter.ts_utils')
++
+ local function map(lhs, rhs)
+ 	vim.keymap.set('n', lhs, function()
+-		-- TODO
++		local node = ts_utils.get_node_at_cursor()
++		if node == nil then
++			error('No Tree-Sitter parser found.')
++		end
+ 	end, {
+ 		buffer = true,
+ 		noremap = true,
diff --git a/src/blog/nvim-ts/get-parent.diff b/src/blog/nvim-ts/get-parent.diff
new file mode 100644
index 0000000..9599792
--- /dev/null
+++ b/src/blog/nvim-ts/get-parent.diff
@@ -0,0 +1,14 @@
+ 		if node == nil then
+ 			error('No Tree-Sitter parser found.')
+ 		end
++
++		while node ~= nil and node:type() ~= 'operation' do
++			node = node:parent()
++		end
++
++		if node ~= nil then
++			-- TODO
++		end
+ 	end, {
+ 		buffer = true,
+ 		noremap = true,
diff --git a/src/blog/nvim-ts/git-log b/src/blog/nvim-ts/git-log
new file mode 100644
index 0000000..d6f7870
--- /dev/null
+++ b/src/blog/nvim-ts/git-log
@@ -0,0 +1,17 @@
+commit 1893588f4f57024098a538d471caeecd01fbe88d
+Author: Thomas Voss <mail@thomasvoss.com>
+Date:   Tue Nov 14 10:36:33 2023 +0100
+
+    Fix another typo
+
+commit b592402d702379d14415c1becf18f6f40c2d6d76
+Author: Thomas Voss <mail@thomasvoss.com>
+Date:   Tue Nov 14 10:12:05 2023 +0100
+
+    Add new blog post
+
+commit 6ae48a4d7a84fd4c76a08a110514754dd6949d46
+Author: Thomas Voss <mail@thomasvoss.com>
+Date:   Tue Nov 14 10:10:53 2023 +0100
+
+    Fix various typos
diff --git a/src/blog/nvim-ts/git-log-2 b/src/blog/nvim-ts/git-log-2
new file mode 100644
index 0000000..0f34811
--- /dev/null
+++ b/src/blog/nvim-ts/git-log-2
@@ -0,0 +1,11 @@
+commit 74ba5ba2b8bdb7708a25283f03542811706072bd
+Author: Thomas Voss <mail@thomasvoss.com>
+Date:   Tue Nov 14 10:12:05 2023 +0100
+
+    Add new blog post
+
+commit a893a1752b1365ec6437095506e6e63979b9236d
+Author: Thomas Voss <mail@thomasvoss.com>
+Date:   Tue Nov 14 10:10:53 2023 +0100
+
+    Fix various typos
diff --git a/src/blog/nvim-ts/git-rebase b/src/blog/nvim-ts/git-rebase
new file mode 100644
index 0000000..f8c3a91
--- /dev/null
+++ b/src/blog/nvim-ts/git-rebase
@@ -0,0 +1,34 @@
+pick d620266 Fix various typos
+pick 59fa2b6 Add new blog post
+pick 4c45214 Fix another typo
+
+# Rebase 10c3013..4c45214 onto 10c3013 (3 commands)
+#
+# Commands:
+# p, pick <commit> = use commit
+# r, reword <commit> = use commit, but edit the commit message
+# e, edit <commit> = use commit, but stop for amending
+# s, squash <commit> = use commit, but meld into previous commit
+# f, fixup [-C | -c] <commit> = like "squash" but keep only the previous
+#                    commit's log message, unless -C is used, in which case
+#                    keep only this commit's message; -c is same as -C but
+#                    opens the editor
+# x, exec <command> = run command (the rest of the line) using shell
+# b, break = stop here (continue rebase later with 'git rebase --continue')
+# d, drop <commit> = remove commit
+# l, label <label> = label current ⁨HEAD⁩ with a name
+# t, reset <label> = reset ⁨HEAD⁩ to a label
+# m, merge [-C <commit> | -c <commit>] <label> [# <oneline>]
+#         create a merge commit using the original merge commit's
+#         message (or the oneline, if no original merge commit was
+#         specified); use -c <commit> to reword the commit message
+# u, update-ref <ref> = track a placeholder for the <ref> to be updated
+#                       to this position in the new commits. The <ref> is
+#                       updated at the end of the rebase
+#
+# These lines can be re-ordered; they are executed from top to bottom.
+#
+# If you remove a line here THAT COMMIT WILL BE LOST.
+#
+# However, if you remove everything, the rebase will be aborted.
+#
diff --git a/src/blog/nvim-ts/git-rebase-2 b/src/blog/nvim-ts/git-rebase-2
new file mode 100644
index 0000000..781738e
--- /dev/null
+++ b/src/blog/nvim-ts/git-rebase-2
@@ -0,0 +1,3 @@
+pick d620266 Fix various typos
+fixup 4c45214 Fix another typo
+pick 59fa2b6 Add new blog post
diff --git a/src/blog/nvim-ts/index.gsp b/src/blog/nvim-ts/index.gsp
new file mode 100644
index 0000000..e394e49
--- /dev/null
+++ b/src/blog/nvim-ts/index.gsp
@@ -0,0 +1,205 @@
+html lang="en" {
+	head { HEAD }
+	body {
+		header {
+			div .head {
+				h1 {-Learn Your Tools}
+				INCLUDE(nav.gsp)
+			}
+
+			figure .quote {
+				blockquote {
+					p {=
+						Vim is a component among other components.  Don’t turn it into a
+						massive application, but have it work well together with other
+						programs.
+					}
+				}
+				figcaption {-Vim Reference Manual}
+			}
+		}
+
+		main {
+			h2 #rebasing {-Git Rebasing}
+			p {=
+				I’m always working with Git.  I use it at work, I use it for my personal
+				projects, I even use it for this site.  Git has become a part of my
+				everyday life.  One Git feature that I use quite often is Git-Rebase,
+				which when invoked with the @code{--i} flag allows you to reorder-,
+				combine-, and delete commits interactively.
+			}
+
+			p {=
+				Let’s say you make two commits called ‘Fix various typos’ and ‘Add new
+				blog post’ in that order.  Now imagine you found another typo that you
+				forgot to fix in your first commit.  You might end up with a history
+				like so:
+			}
+
+			figure { FMT_CODE(git-log) }
+
+			p {=
+				While for many people this might be fine, I personally find it much more
+				clean to have the first and third commits merged into one commit, as
+				they’re two parts of the same task.  This is where Git-Rebase comes in.
+				We can run @code{-git rebase -i ⁨HEAD⁩~N} where @code{-N} is
+				the number of commits back we want to include, which in this case would
+				be 3.  Running that command will open the following buffer in your text
+				editor.  In my case, Neovim.
+			}
+
+			figure { FMT_CODE(git-rebase) }
+
+			p {=
+				As suggested by the comments added to the bottom of the opened buffer,
+				we can combine the two typo-fixing commits by simply swapping the 2nd-
+				and 3rd lines, and then changing the second typo-fixing commit from a
+				@em{-pick} to a @em{-fixup}:
+			}
+
+			figure { FMT_CODE(git-rebase-2) }
+
+			p {=
+				After saving and exiting from your editor, the Git log should now only
+				have two entries, which looks a lot cleaner.
+			}
+
+			figure { FMT_CODE(git-log-2) }
+
+			h2 #problem {-The Problem}
+			p {=
+				This is fine and all, but it could be better.  Specifically, it would be
+				nice if instead of having to navigate to the front of the line, delete
+				the word, and replace it with something new (such as @em{-fixup}), you
+				could just hit ‘@kbd{-f}’ on your keyboard with your cursor on the right
+				line and have it edit the command for you.  Along with fixups, it would
+				also be nice to be able to press ‘@kbd{-s}’ for @em{-squash}, ‘@kbd{-r}’
+				for @em{-reword}, etc.
+			}
+
+			p {=
+				Seeing as the Git-Rebase interface is line-based with a simple syntax,
+				you could probably easily do this with a regular-expression-based
+				solution.  I’m going to use Tree-Sitter though because it’s cooler, and
+				I want to show off how easy it is to use.
+			}
+
+			h2 #plugin {-Writing The Plugin}
+			p {=
+				The first thing to figure out is where to put the plugin.  Seeing as we
+				only want it active when we’re performing a rebase, we can make use of
+				the @code{-after/ftplugin} directory.  Configurations placed in this
+				directory will only be applied when working in a buffer whose filetype
+				corresponds to the filename.  By running @code{-:set ft?} in a
+				Git-Rebase buffer we can see that the filetype is ‘@code{-gitrebase}’,
+				so with all that information we know that we can put our plugin in
+				@code{-after/ftplugin/gitrebase.lua}.
+			}
+
+			p {=
+				The basic skeleton of the plugin is going to look like so:
+			}
+
+			figure {
+				figcaption {
+					code {-after/ftplugin/gitrebase.lua}
+				}
+				FMT_CODE(skeleton.lua)
+			}
+
+			p {=
+				The @code{-map} function defined here will create a normal-mode
+				keybinding where pressing the key combination provided as the first
+				argument will replace the Git-Rebase command of the current line with
+				the string provided in the second argument.  The actual function to
+				perform this replacement isn’t implemented yet, so in its current state
+				it will bind these keys to an empty function.  We also pass a few
+				options to @code{-vim.keymap.set}; you can read more about these in
+				@code{-:help vim.keymap.set} if you’re interested.
+			}
+
+			p {=
+				The first step to implementing the actual functionality of the plugin is
+				to figure out where we are.  We can do this very easily with the Neovim
+				Tree-Sitter API:
+			}
+
+			figure { FMT_CODE(get-cursor.diff) }
+
+			p {-
+				The @code{-ts_utils.get_node_at_cursor()} function will return to us the
+				current node in the Tree-Sitter parse tree that our cursor is located
+				at.  In the case that we don’t have a Tree-Sitter parser available, the
+				node will be @code{-nil} and we can just issue an error.
+			}
+
+			p {=
+				Before making any more progress, it’s a good idea to make sure you have
+				a proper understanding of the structure of the @code{-gitrebase} AST.
+				You can view the AST by opening a new @code{-gitrebase} buffer and
+				running @code{-:vim.treesitter.inspect_tree()}.  I implore you to do
+				this yourself, you’ll learn from it.  The AST will end up looking
+				something like this, followed by a bunch of @code{-(comment)}s:
+			}
+
+			figure { FMT_CODE(ts-tree.scm) }
+
+			p {=
+				As you can see, each line is represented by an @em{-operation} node
+				which has three child nodes: a @em{-command}, a @em{-label}, and a
+				@em{-message}.  You can probably begin to realize now that we’re going
+				to want to get- and modify the @em{-command} node on the line that our
+				cursor is on.
+			}
+
+			p {=
+				In the code above we got the node at our cursor, now we need to traverse
+				the AST to the operation node.  We can call the @code{-:parent()} method
+				on our node in a loop to traverse up the tree until we reach our target
+				node.  If our cursor isn’t on a valid line such as on a comment or a
+				blank line we won’t ever hit an operation node and will instead get
+				@code{-nil}, so we need to handle that case too.
+			}
+
+			figure { FMT_CODE(get-parent.diff) }
+
+			p {=
+				Now that we have the operation node, we simply have to get the child
+				command node (which we know is the first child node), find out where in
+				the buffer it is, and replace it.  We can call the @code{-:child(0)}
+				method on our node to get the first child, and then call the
+				@code{-:range()} method on the child to get position in our buffer of
+				the command node.  The @code{-:range()} method returns 4 values: the
+				start row, start column, end row, and end column.  We can then pass
+				these positions to @code{-vim.api.nvim_buf_set_text()} to set the text
+				at the given position.
+			}
+
+			figure { FMT_CODE(change-command.diff) }
+
+			p {-
+				And that is the entire plugin!  In just 28 lines of code (including
+				whitespace) we implemented a plugin using Tree-Sitter to allow you to
+				modify a Git-Rebase command with a single keystroke.  The completed
+				product looks like so:
+			}
+
+			figure {
+				figcaption {
+					code {-after/ftplugin/gitrebase.lua}
+				}
+				FMT_CODE(final.lua)
+			}
+
+			figure {
+				figcaption {-Example Usage}
+				video width="100%" height="720" controls {=
+					@source src="final.webm" type="video/webm" {}
+					Your browser does not support the video tag.
+				}
+			}
+		}
+
+		footer { FOOT }
+	}
+}
diff --git a/src/blog/nvim-ts/skeleton.lua b/src/blog/nvim-ts/skeleton.lua
new file mode 100644
index 0000000..0f9a54d
--- /dev/null
+++ b/src/blog/nvim-ts/skeleton.lua
@@ -0,0 +1,14 @@
+local function map(lhs, rhs)
+	vim.keymap.set('n', lhs, function()
+		--- TODO
+	end, {
+		buffer = true,
+		noremap = true,
+		silent = true,
+	})
+end
+
+map('p', 'pick')
+map('r', 'reword')
+map('s', 'squash')
+map('f', 'fixup')
diff --git a/src/blog/nvim-ts/ts-tree.scm b/src/blog/nvim-ts/ts-tree.scm
new file mode 100644
index 0000000..e255ade
--- /dev/null
+++ b/src/blog/nvim-ts/ts-tree.scm
@@ -0,0 +1,12 @@
+(operation) ; [1:1 - 30]
+ (command) ; [1:1 - 4]
+ (label) ; [1:6 - 12]
+ (message) ; [1:14 - 30]
+(operation) ; [2:1 - 30]
+ (command) ; [2:1 - 4]
+ (label) ; [2:6 - 12]
+ (message) ; [2:14 - 30]
+(operation) ; [3:1 - 29]
+ (command) ; [3:1 - 4]
+ (label) ; [3:6 - 12]
+ (message) ; [3:14 - 29]
diff --git a/src/style.css b/src/style.css
index cdde775..8e37c5f 100644
--- a/src/style.css
+++ b/src/style.css
@@ -6,6 +6,20 @@
 	color-scheme: light dark;
 }
 
+@media (prefers-color-scheme: light) {
+	:root {
+		--fg: black;
+		--bg: white;
+	}
+}
+
+@media (prefers-color-scheme: dark) {
+	:root {
+		--fg: white;
+		--bg: black;
+	}
+}
+
 body {
 	text-align: justify;
 	width: min(800px, 90%);
@@ -23,19 +37,8 @@ blockquote + figcaption {
 	font-style: italic;
 }
 
-@media (prefers-color-scheme: light) {
-	.quote {
-		border-left: 4px solid black;
-	}
-}
-
-@media (prefers-color-scheme: dark) {
-	.quote {
-		border-left: 4px solid white;
-	}
-}
-
 .quote {
+	border-left: 4px solid var(--fg);
 	padding: .4rem .8rem;
 	margin-inline: 1rem 0;
 	margin-block: 2rem;
@@ -77,3 +80,39 @@ header div.head menu {
 header div.head li {
 	list-style: none;
 }
+
+.article {
+	display: flex;
+	justify-content: space-between;
+}
+
+figure pre.code-sample {
+	overflow-x: scroll;
+}
+
+figure pre.code-sample > code {
+	counter-increment: line;
+}
+
+figure pre.code-sample > code::before {
+	position: absolute;
+
+	margin-left: -4ch;
+	padding-right: .5ch;
+	width: 3ch;
+
+	text-align: right;
+	content: counter(line);
+	color: var(--fg);
+	border-right: 1px solid var(--fg);
+}
+
+footer {
+	margin-block: 2rem;
+	text-align: center;
+	font-style: italic;
+}
+
+ins, del { text-decoration: none; }
+ins      { color: green; }
+del      { color: red;   }