From 1e7c5902eac8ad139c50fdda7685a3aecd7a45ea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Pankowski?= <lukpank@o2.pl>
Date: Mon, 22 Sep 2025 22:46:16 +0200
Subject: [PATCH] vis: templ: add (implement) templ lexer

---
 vis/.config/vis/lexers/templ.lua | 106 +++++++++++++++----------------
 1 file changed, 50 insertions(+), 56 deletions(-)

diff --git a/vis/.config/vis/lexers/templ.lua b/vis/.config/vis/lexers/templ.lua
index 649a85a..7ca5bd9 100644
--- a/vis/.config/vis/lexers/templ.lua
+++ b/vis/.config/vis/lexers/templ.lua
@@ -1,71 +1,65 @@
 -- Copyright 2006-2025 Mitchell. See LICENSE.
--- Go LPeg lexer.
+-- templ LPeg lexer.
 
 local lexer = lexer
+local starts_line = lexer.starts_line
 local P, S = lpeg.P, lpeg.S
 
-local lex = lexer.new(...)
+local lex = lexer.new(..., {inherit = lexer.load('go')})
 
--- Keywords.
-lex:add_rule('keyword', lex:tag(lexer.KEYWORD, lex:word_match(lexer.KEYWORD)))
+local close_paren = lex:tag(lexer.OPERATOR, P(')'))
+local open_brace = lex:tag(lexer.OPERATOR, P('{'))
+local close_brace = lex:tag(lexer.OPERATOR, P('}'))
+local colon = lex:tag(lexer.OPERATOR, P(':'))
+local at = lex:tag(lexer.OPERATOR, P('@'))
+local ws = lex:get_rule('whitespace')
+local ident = lex:get_rule('identifier')
 
--- Constants.
-lex:add_rule('constant', lex:tag(lexer.CONSTANT_BUILTIN, lex:word_match(lexer.CONSTANT_BUILTIN)))
+local html = lexer.load('html')
+local go_expr = lexer.load('go', 'go.expr')
+local go_stmt1 = lexer.load('go', 'go.stmt1')
+local go_stmt2 = lexer.load('go', 'go.stmt2')
+local go_stmt3 = lexer.load('go', 'go.stmt3')
+local for_ = lex:tag(lexer.KEYWORD, lexer.word_match('for if switch'))
+local else_ = close_brace * ws^0 * lex:tag(lexer.KEYWORD, P('else'))
+local case_ = lex:tag(lexer.KEYWORD, lexer.word_match('case default'))
+html:embed(go_expr, open_brace, close_brace * close_brace^-1)
+html:embed(go_stmt1, starts_line(for_ + else_, true), open_brace * #lexer.newline)
+html:embed(go_stmt2, starts_line(case_, true), colon * #lexer.newline)
+html:embed(go_stmt3, starts_line(at, true), (ident + open_brace + close_paren) * #lexer.newline)
 
--- Types.
-lex:add_rule('type', lex:tag(lexer.TYPE, lex:word_match(lexer.TYPE)))
+local func_block_start = close_paren * ws^0 * open_brace
 
--- Functions.
-local builtin_func = -lpeg.B('.') *
-	lex:tag(lexer.FUNCTION_BUILTIN, lex:word_match(lexer.FUNCTION_BUILTIN))
-local func = lex:tag(lexer.FUNCTION, lexer.word)
-local method = lpeg.B('.') * lex:tag(lexer.FUNCTION_METHOD, lexer.word)
-lex:add_rule('function', (builtin_func + method + func) * #(lexer.space^0 * '('))
+lex:set_word_list(lexer.KEYWORD, 'templ css script', true)
 
--- Identifiers.
-lex:add_rule('identifier', lex:tag(lexer.IDENTIFIER, lexer.word))
+local function starts_with(keyword)
+	local prefix = '\n' .. keyword .. '%s'
+	return function(input, index)
+		local i = index - 1024
+		if i < 1 then
+			i = 1
+		end
+		local s = input:sub(i, index)
+		local k = 0
+		repeat
+			i = s:find('\n%w', i)
+			if i then
+				k = i
+				i = i + 2
+			end
+		until not i
+		return k > 0 and s:find(prefix, k) and true
+	end
+end
 
--- Strings.
-local sq_str = lexer.range("'", true)
-local dq_str = lexer.range('"', true)
-local raw_str = lexer.range('`', false, false)
-lex:add_rule('string', lex:tag(lexer.STRING, sq_str + dq_str + raw_str))
+lex:embed(html, func_block_start * P(starts_with("templ")), starts_line(close_brace))
 
--- Comments.
-local line_comment = lexer.to_eol('//')
-local block_comment = lexer.range('/*', '*/')
-lex:add_rule('comment', lex:tag(lexer.COMMENT, line_comment + block_comment))
+local css = lexer.load('css')
+local css_go_expr = lexer.load('go', 'go.expr2')
+css:embed(css_go_expr, open_brace, close_brace)
+lex:embed(css, func_block_start * P(starts_with("css")), starts_line(close_brace))
 
--- Numbers.
-lex:add_rule('number', lex:tag(lexer.NUMBER, lexer.number * P('i')^-1))
-
--- Operators.
-lex:add_rule('operator', lex:tag(lexer.OPERATOR, S('+-*/%&|^<>=!~:;.,()[]{}@')))
-
--- Fold points.
-lex:add_fold_point(lexer.OPERATOR, '{', '}')
-lex:add_fold_point(lexer.COMMENT, '/*', '*/')
-
--- Word lists.
-lex:set_word_list(lexer.KEYWORD, {
-	'break', 'case', 'chan', 'const', 'continue', 'default', 'defer', 'else', 'fallthrough', 'for',
-	'func', 'go', 'goto', 'if', 'import', 'interface', 'map', 'package', 'range', 'return', 'select',
-	'struct', 'switch', 'type', 'var', 'templ'
-})
-
-lex:set_word_list(lexer.CONSTANT_BUILTIN, 'true false iota nil')
-
-lex:set_word_list(lexer.TYPE, {
-	'any', 'bool', 'byte', 'comparable', 'complex64', 'complex128', 'error', 'float32', 'float64',
-	'int', 'int8', 'int16', 'int32', 'int64', 'rune', 'string', 'uint', 'uint8', 'uint16', 'uint32',
-	'uint64', 'uintptr'
-})
-
-lex:set_word_list(lexer.FUNCTION_BUILTIN, {
-	'append', 'cap', 'close', 'complex', 'copy', 'delete', 'imag', 'len', 'make', 'new', 'panic',
-	'print', 'println', 'real', 'recover'
-})
-
-lexer.property['scintillua.comment'] = '//'
+local js = lexer.load('javascript')
+lex:embed(js, func_block_start * P(starts_with("script")), starts_line(close_brace))
 
 return lex