From 0fdcfcc9c072e80d82cce9ff93d629b3e46bfac0 Mon Sep 17 00:00:00 2001
From: arne314 <73391160+arne314@users.noreply.github.com>
Date: Thu, 15 May 2025 00:33:36 +0200
Subject: [PATCH] refactor(snip): separate engine and helpers

---
 lua/typstar/autosnippets.lua | 171 +---------------------------------
 lua/typstar/engine.lua       | 172 +++++++++++++++++++++++++++++++++++
 2 files changed, 173 insertions(+), 170 deletions(-)
 create mode 100644 lua/typstar/engine.lua

diff --git a/lua/typstar/autosnippets.lua b/lua/typstar/autosnippets.lua
index c36a239..611a775 100644
--- a/lua/typstar/autosnippets.lua
+++ b/lua/typstar/autosnippets.lua
@@ -1,32 +1,5 @@
-local M = {}
-local cfg = require('typstar.config').config.snippets
+local M = require('typstar.engine') -- inherit all functions
 local luasnip = require('luasnip')
-local utils = require('typstar.utils')
-local fmta = require('luasnip.extras.fmt').fmta
-local lsengines = require('luasnip.nodes.util.trig_engines')
-local ts = vim.treesitter
-
-local exclude_triggers_set = {}
-local last_keystroke_time = nil
-local lexical_result_cache = {}
-local ts_markup_query = ts.query.parse('typst', '(text) @markup')
-local ts_math_query = ts.query.parse('typst', '(math) @math')
-local ts_string_query = ts.query.parse('typst', '(string) @string')
-
-utils.generate_bool_set(cfg.exclude, exclude_triggers_set)
-vim.api.nvim_create_autocmd('TextChangedI', {
-    callback = function() last_keystroke_time = vim.loop.now() end,
-})
-
-M.in_math = function()
-    local cursor = utils.get_cursor_pos()
-    return utils.cursor_within_treesitter_query(ts_math_query, 0, cursor)
-        and not utils.cursor_within_treesitter_query(ts_string_query, 0, cursor)
-end
-M.in_markup = function() return utils.cursor_within_treesitter_query(ts_markup_query, 2) end
-M.not_in_math = function() return not M.in_math() end
-M.not_in_markup = function() return not M.in_markup() end
-M.snippets_toggle = true
 
 function M.cap(i)
     return luasnip.function_node(function(_, snip) return snip.captures[i] end)
@@ -68,33 +41,6 @@ function M.ri(insert_node_id)
     return luasnip.function_node(function(args) return args[1][1] end, insert_node_id)
 end
 
-function M.snip(trigger, expand, insert, condition, priority, options)
-    priority = priority or 1000
-    options = vim.tbl_deep_extend('force', {
-        maxTrigLength = nil,
-        wordTrig = true,
-        blacklist = {},
-        prepend = nil,
-    }, options or {})
-    if options.prepend ~= nil then
-        expand, insert = M.blocktransform(expand, insert, options.prepend, true)
-    end
-    return luasnip.snippet(
-        {
-            trig = trigger,
-            trigEngine = M.engine,
-            trigEngineOpts = vim.tbl_deep_extend('keep', { condition = condition }, options),
-            wordTrig = false,
-            priority = priority,
-            snippetType = 'autosnippet',
-        },
-        fmta(expand, { unpack(insert) }),
-        {
-            condition = function() return M.snippets_toggle end,
-        }
-    )
-end
-
 function M.start_snip(trigger, expand, insert, condition, priority, options)
     return M.snip('^(\\s*)' .. trigger, '<>' .. expand, { M.cap(1), unpack(insert) }, condition, priority, options)
 end
@@ -176,119 +122,4 @@ function M.bulletpoint_snip(trigger, expand, insert, condition, priority, option
         options
     )
 end
-
-local alts_regex = '[\\[\\(](.*|.*)[\\)\\]]'
-
-function M.engine(trigger, opts)
-    local base_engine = lsengines.ecma(trigger, opts)
-
-    -- determine possibly max/fixed length of trigger
-    local max_length = opts.maxTrigLength
-    local is_fixed_length = false
-    if max_length == nil and alts_regex ~= '' and not trigger:match('[%+%*]') then
-        max_length = #trigger
-            - utils.count_string(trigger, '\\')
-            - utils.count_string(trigger, '%(')
-            - utils.count_string(trigger, '%)')
-            - utils.count_string(trigger, '%?')
-        is_fixed_length = not trigger:match('[%+%*%?%[%]|]')
-
-        local alts_match = alts_regex:match(trigger) -- find longest trigger in [...|...]
-        if alts_match then
-            for _, alts in ipairs(alts_match) do
-                local max_alt_length = 1
-                for alt in alts:gmatch('([^|]+)') do
-                    local len
-                    if alt:match('%[.*-.*%]') then -- [A-Za-z0-9] and similar
-                        len = 2
-                    else
-                        len = #alt
-                    end
-                    max_alt_length = math.max(max_alt_length, len)
-                end
-                max_length = max_length - (#alts - max_alt_length)
-            end
-        else -- [^...] and similar
-            max_length = max_length - utils.count_string(trigger, '%[') - utils.count_string(trigger, '%]')
-        end
-    end
-
-    -- cache preanalysis results
-    local condition = function()
-        local cached = lexical_result_cache[opts.condition]
-        if cached ~= nil and cached[1] == last_keystroke_time then return cached[2] end
-        local result = opts.condition()
-        lexical_result_cache[opts.condition] = { last_keystroke_time, result }
-        return result
-    end
-
-    -- matching
-    return function(line_full, trig)
-        if not M.snippets_toggle or not condition() then return nil end
-        local first_idx = 1
-        if max_length ~= nil then
-            first_idx = #line_full - max_length -- include additional char for wordtrig
-            if first_idx < 0 then
-                if is_fixed_length then
-                    return nil
-                else
-                    first_idx = 1
-                end
-            end
-            if first_idx > 0 then
-                if string.byte(line_full, first_idx) > 127 then return nil end
-            end
-        end
-        local line = line_full:sub(first_idx)
-        local whole, captures = base_engine(line, trig)
-        if whole == nil then return nil end
-
-        -- custom word trig
-        local from = #line - #whole + 1
-        if opts.wordTrig and from ~= 1 and string.match(string.sub(line, from - 1, from - 1), '[%w.]') ~= nil then
-            return nil
-        end
-
-        -- blacklist
-        for _, w in ipairs(opts.blacklist) do
-            if line_full:sub(-#w) == w then return nil end
-        end
-        return whole, captures
-    end
-end
-
-function M.toggle_autosnippets()
-    M.snippets_toggle = not M.snippets_toggle
-    print(string.format('%sabled typstar autosnippets', M.snippets_toggle and 'En' or 'Dis'))
-end
-
-function M.setup()
-    if cfg.enable then
-        local jsregexp_ok, jsregexp = pcall(require, 'luasnip-jsregexp')
-        if not jsregexp_ok then
-            jsregexp_ok, jsregexp = pcall(require, 'jsregexp')
-        end
-        if jsregexp_ok then
-            if type(alts_regex) == 'string' then alts_regex = jsregexp.compile_safe(alts_regex) end
-        else
-            alts_regex = ''
-            vim.notify("WARNING: Most snippets won't work as jsregexp is not installed", vim.log.levels.WARN)
-        end
-        local autosnippets = {}
-        for _, file in ipairs(cfg.modules) do
-            for _, sn in ipairs(require(('typstar.snippets.%s'):format(file))) do
-                local exclude
-                local is_start = sn.trigger:match('^%^%(\\s%*%)')
-                if is_start then
-                    exclude = exclude_triggers_set[sn.trigger:sub(7)]
-                else
-                    exclude = exclude_triggers_set[sn.trigger]
-                end
-                if not exclude then table.insert(autosnippets, sn) end
-            end
-        end
-        luasnip.add_snippets('typst', autosnippets)
-    end
-end
-
 return M
diff --git a/lua/typstar/engine.lua b/lua/typstar/engine.lua
new file mode 100644
index 0000000..19885ba
--- /dev/null
+++ b/lua/typstar/engine.lua
@@ -0,0 +1,172 @@
+local M = {}
+local cfg = require('typstar.config').config.snippets
+local luasnip = require('luasnip')
+local utils = require('typstar.utils')
+local fmta = require('luasnip.extras.fmt').fmta
+local lsengines = require('luasnip.nodes.util.trig_engines')
+local ts = vim.treesitter
+
+local exclude_triggers_set = {}
+local last_keystroke_time = nil
+local lexical_result_cache = {}
+local ts_markup_query = ts.query.parse('typst', '(text) @markup')
+local ts_math_query = ts.query.parse('typst', '(math) @math')
+local ts_string_query = ts.query.parse('typst', '(string) @string')
+
+utils.generate_bool_set(cfg.exclude, exclude_triggers_set)
+vim.api.nvim_create_autocmd('TextChangedI', {
+    callback = function() last_keystroke_time = vim.loop.now() end,
+})
+
+M.in_math = function()
+    local cursor = utils.get_cursor_pos()
+    return utils.cursor_within_treesitter_query(ts_math_query, 0, cursor)
+        and not utils.cursor_within_treesitter_query(ts_string_query, 0, cursor)
+end
+M.in_markup = function() return utils.cursor_within_treesitter_query(ts_markup_query, 2) end
+M.not_in_math = function() return not M.in_math() end
+M.not_in_markup = function() return not M.in_markup() end
+M.snippets_toggle = true
+
+function M.snip(trigger, expand, insert, condition, priority, options)
+    priority = priority or 1000
+    options = vim.tbl_deep_extend('force', {
+        maxTrigLength = nil,
+        wordTrig = true,
+        blacklist = {},
+        prepend = nil,
+    }, options or {})
+    if options.prepend ~= nil then
+        expand, insert = M.blocktransform(expand, insert, options.prepend, true)
+    end
+    return luasnip.snippet(
+        {
+            trig = trigger,
+            trigEngine = M.engine,
+            trigEngineOpts = vim.tbl_deep_extend('keep', { condition = condition }, options),
+            wordTrig = false,
+            priority = priority,
+            snippetType = 'autosnippet',
+        },
+        fmta(expand, { unpack(insert) }),
+        {
+            condition = function() return M.snippets_toggle end,
+        }
+    )
+end
+
+local alts_regex = '[\\[\\(](.*|.*)[\\)\\]]'
+
+function M.engine(trigger, opts)
+    local base_engine = lsengines.ecma(trigger, opts)
+
+    -- determine possibly max/fixed length of trigger
+    local max_length = opts.maxTrigLength
+    local is_fixed_length = false
+    if max_length == nil and alts_regex ~= '' and not trigger:match('[%+%*]') then
+        max_length = #trigger
+            - utils.count_string(trigger, '\\')
+            - utils.count_string(trigger, '%(')
+            - utils.count_string(trigger, '%)')
+            - utils.count_string(trigger, '%?')
+        is_fixed_length = not trigger:match('[%+%*%?%[%]|]')
+
+        local alts_match = alts_regex:match(trigger) -- find longest trigger in [...|...]
+        if alts_match then
+            for _, alts in ipairs(alts_match) do
+                local max_alt_length = 1
+                for alt in alts:gmatch('([^|]+)') do
+                    local len
+                    if alt:match('%[.*-.*%]') then -- [A-Za-z0-9] and similar
+                        len = 2
+                    else
+                        len = #alt
+                    end
+                    max_alt_length = math.max(max_alt_length, len)
+                end
+                max_length = max_length - (#alts - max_alt_length)
+            end
+        else -- [^...] and similar
+            max_length = max_length - utils.count_string(trigger, '%[') - utils.count_string(trigger, '%]')
+        end
+    end
+
+    -- cache preanalysis results
+    local condition = function()
+        local cached = lexical_result_cache[opts.condition]
+        if cached ~= nil and cached[1] == last_keystroke_time then return cached[2] end
+        local result = opts.condition()
+        lexical_result_cache[opts.condition] = { last_keystroke_time, result }
+        return result
+    end
+
+    -- matching
+    return function(line_full, trig)
+        if not M.snippets_toggle or not condition() then return nil end
+        local first_idx = 1
+        if max_length ~= nil then
+            first_idx = #line_full - max_length -- include additional char for wordtrig
+            if first_idx < 0 then
+                if is_fixed_length then
+                    return nil
+                else
+                    first_idx = 1
+                end
+            end
+            if first_idx > 0 then
+                if string.byte(line_full, first_idx) > 127 then return nil end
+            end
+        end
+        local line = line_full:sub(first_idx)
+        local whole, captures = base_engine(line, trig)
+        if whole == nil then return nil end
+
+        -- custom word trig
+        local from = #line - #whole + 1
+        if opts.wordTrig and from ~= 1 and string.match(string.sub(line, from - 1, from - 1), '[%w.]') ~= nil then
+            return nil
+        end
+
+        -- blacklist
+        for _, w in ipairs(opts.blacklist) do
+            if line_full:sub(-#w) == w then return nil end
+        end
+        return whole, captures
+    end
+end
+
+function M.toggle_autosnippets()
+    M.snippets_toggle = not M.snippets_toggle
+    print(string.format('%sabled typstar autosnippets', M.snippets_toggle and 'En' or 'Dis'))
+end
+
+function M.setup()
+    if cfg.enable then
+        local jsregexp_ok, jsregexp = pcall(require, 'luasnip-jsregexp')
+        if not jsregexp_ok then
+            jsregexp_ok, jsregexp = pcall(require, 'jsregexp')
+        end
+        if jsregexp_ok then
+            if type(alts_regex) == 'string' then alts_regex = jsregexp.compile_safe(alts_regex) end
+        else
+            alts_regex = ''
+            vim.notify("WARNING: Most snippets won't work as jsregexp is not installed", vim.log.levels.WARN)
+        end
+        local autosnippets = {}
+        for _, file in ipairs(cfg.modules) do
+            for _, sn in ipairs(require(('typstar.snippets.%s'):format(file))) do
+                local exclude
+                local is_start = sn.trigger:match('^%^%(\\s%*%)')
+                if is_start then
+                    exclude = exclude_triggers_set[sn.trigger:sub(7)]
+                else
+                    exclude = exclude_triggers_set[sn.trigger]
+                end
+                if not exclude then table.insert(autosnippets, sn) end
+            end
+        end
+        luasnip.add_snippets('typst', autosnippets)
+    end
+end
+
+return M