From c273afbf4e9c9d8c7852d82b4ba98830d141a208 Mon Sep 17 00:00:00 2001
From: arne314 <73391160+arne314@users.noreply.github.com>
Date: Tue, 14 Jan 2025 20:25:16 +0100
Subject: [PATCH] feat(snip): series of numbered letters

---
 README.md                        |  5 ++--
 lua/typstar/snippets/letters.lua | 41 ++++++++++++++++++++++----------
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 8029b02..b37e11d 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Available snippets can mostly be intuitively derived from [here](././lua/typstar
 
 Markup snippets:
 - Begin inline math with `ll` and multiline math with `dm`
-- [Markup shorthands](./lua/typstar/snippets/markup.lua) (e.g. `HIG` &#8594; `#highlight[<cursor>]`, `IMP` &#8594; `$=>$ `)
+- [Markup shorthands](./lua/typstar/snippets/markup.lua) (e.g. `HIG` &#8594; `#highlight[<cursor>]`, `IMP` &#8594; `$==>$ `)
 - [ctheorems shorthands](./lua/typstar/snippets/markup.lua) (e.g. `tem` &#8594; empty theorem, `exa` &#8594; empty example)
 - [Flashcards](#anki): `fla` and `flA`
 - All above snippets support visual mode via the [selection key](#installation)
@@ -23,7 +23,8 @@ Math snippets:
 - [Many shorthands](./lua/typstar/snippets/math.lua) for mathematical expressions
 - Alphanumeric characters: `:<char>` &#8594; `$<char>$ ` in markup (e.g. `:X` &#8594; `$X$ `, `:5` &#8594; `$5$ `)
 - Greek letters: `;<latin>` &#8594; `<greek>` in math and `$<greek>$ ` in markup (e.g. `;a` &#8594; `alpha`/`$alpha$ `)
-- Common indices (numbers and letters `i-n`): `<letter><index>` &#8594; `<letter>_<index>` in math and `$<letter>$<index> ` &#8594; `$<letter>_<index>$ ` in markup (e.g `A314` &#8594; `A_314`, `$alpha$n ` &#8594; `$alpha_n$ `)
+- Common indices (numbers and letters `i-n`): `<letter><index> ` &#8594; `<letter>_<index> ` in math and `$<letter>$<index> ` &#8594; `$<letter>_<index>$ ` in markup (e.g `A314 ` &#8594; `A_314 `, `$alpha$n ` &#8594; `$alpha_n$ `)
+- Series of numbered letters: `<letter> ot<optional last index> ` &#8594; `<letter>_1, <letter>_2, ... ` (e.g. `a ot ` &#8594; `a_1, a_2, ... `, `a ot4 ` &#8594; `a_1, a_2, a_3, a_4 `, `alpha ot k ` &#8594; `alpha_1, alpha_2, ..., alpha_k `)
 - Wrapping of any mathematical expression (see [operations](./lua/typstar/snippets/visual.lua), works nested, multiline and in visual mode via the [selection key](#installation)): `<expression><operation>` &#8594; `<operation>(<expression>)` (e.g. `(a^2+b^2)rt` &#8594; `sqrt(a^2+b^2)`, `lambdatd` &#8594; `tilde(lambda)`, `(1+1)sQ` &#8594; `[1+1]`, `(1+1)sq` &#8594; `[(1+1)]`)
 - Matrices: `<size>ma` and `<size>lma` (e.g. `23ma` &#8594; 2x3 matrix)
 
diff --git a/lua/typstar/snippets/letters.lua b/lua/typstar/snippets/letters.lua
index 6cc6257..8400f16 100644
--- a/lua/typstar/snippets/letters.lua
+++ b/lua/typstar/snippets/letters.lua
@@ -76,24 +76,41 @@ local get_index = function(_, snippet)
     return s(nil, t(letter .. '_' .. index))
 end
 
-table.insert(letter_snippets, snip(':([A-Za-z0-9])', '$<>$ ', { cap(1) }, markup))
-table.insert(letter_snippets, snip(';(' .. trigger_greek .. ')', '$<>$ ', { d(1, get_greek) }, markup))
-table.insert(letter_snippets, snip(';(' .. trigger_greek .. ')', '<>', { d(1, get_greek) }, math))
-table.insert(
-    letter_snippets,
+local get_series = function(_, snippet)
+    local letter, target = snippet.captures[1], snippet.captures[2]
+    local target_num = tonumber(target)
+    local result
+    if target_num then
+        local res = {}
+        for n = 1, target_num do
+            table.insert(res, string.format('%s_%d', letter, n))
+            if n ~= target_num then table.insert(res, ', ') end
+        end
+        result = table.concat(res, '')
+    else
+        result = string.format('%s_1, %s_2, ... %s_%s', letter, letter, letter, target)
+    end
+    return s(nil, t(result))
+end
+
+return {
+    -- latin/greek
+    snip(':([A-Za-z0-9])', '$<>$ ', { cap(1) }, markup),
+    snip(';(' .. trigger_greek .. ')', '$<>$ ', { d(1, get_greek) }, markup),
+    snip(';(' .. trigger_greek .. ')', '<>', { d(1, get_greek) }, math),
+
+    -- indices
     snip(
         '\\$(' .. trigger_index_pre .. ')\\$' .. '(' .. trigger_index_post .. ') ',
         '$<>$ ',
         { d(1, get_index) },
         markup,
         500
-    )
-)
-table.insert(
-    letter_snippets,
-    snip('(' .. trigger_index_pre .. ')' .. '(' .. trigger_index_post .. ') ', '<> ', { d(1, get_index) }, math, 200)
-)
+    ),
+    snip('(' .. trigger_index_pre .. ')' .. '(' .. trigger_index_post .. ') ', '<> ', { d(1, get_index) }, math, 200),
 
-return {
+    -- series of numbered letters
+    snip('(' .. trigger_index_pre .. ') ot ', '<>_1, <>_2, ... ', { cap(1), cap(1) }, math), -- a_1, a_2, ...
+    snip('(' .. trigger_index_pre .. ') ot(\\w+) ', '<> ', { d(1, get_series) }, math), -- a_1, a_2, ... a_j or a_1, a_2, a_2, a_3, a_4, a_5
     unpack(letter_snippets),
 }