Catch a lexer's failure in one place

filter_close already runs highlight under pcall and serves the escaped
text when it fails, so the pcalls around detect, load and lex inside it
only turned a raise into the same fallback a step earlier.

1 file changed, 9 insertions, 12 deletions

diff --git a/custom/extensions/syntax-highlight.lua b/custom/extensions/syntax-highlight.luaindex 639ad3f..3a4fa9b 100644--- a/custom/extensions/syntax-highlight.lua+++ b/custom/extensions/syntax-highlight.lua@@ -151,17 +151,11 @@ local function load_scintillua() 	return nil end --- Detecting and loading a lexer run Scintillua's own Lua, and code written--- for another version of it can raise, so a failure in either just leaves--- this file uncoloured. The first line goes along to detect(), so a script--- with no extension is still known by its shebang.+-- The first line goes along to detect(), so a script with no extension is+-- still known by its shebang. local function lexer_for(name, text)-	local ok, lang = pcall(scintillua.detect, name, string.match(text, "^[^\n]*"))-	if not ok or not lang then-		return nil-	end-	local loaded, lexer = pcall(scintillua.load, lang)-	return loaded and lexer or nil+	local lang = scintillua.detect(name, string.match(text, "^[^\n]*"))+	return lang and scintillua.load(lang) end  local function highlight(text)@@ -169,8 +163,8 @@ local function highlight(text) 	if not lexer then 		return nil 	end-	local ok, tokens = pcall(lexer.lex, lexer, text)-	if not ok or type(tokens) ~= "table" then+	local tokens = lexer:lex(text)+	if type(tokens) ~= "table" then 		return nil 	end 	local out = {}@@ -223,6 +217,9 @@ function filter_close() 			scintillua = load_scintillua() or false 		end 		if scintillua then+			-- Every step of highlight runs Scintillua's own Lua, and code+			-- written for another version of it can raise, so a failure+			-- anywhere there just leaves this file uncoloured. 			local ok, marked = pcall(highlight, text) 			if ok and marked then 				html(marked)
diff --git a/custom/extensions/syntax-highlight.lua b/custom/extensions/syntax-highlight.lua
index 639ad3f..3a4fa9b 100644
--- a/custom/extensions/syntax-highlight.lua
+++ b/custom/extensions/syntax-highlight.lua
@@ -151,17 +151,11 @@ local function load_scintillua()
 	return nil
 end
 
--- Detecting and loading a lexer run Scintillua's own Lua, and code written
--- for another version of it can raise, so a failure in either just leaves
--- this file uncoloured. The first line goes along to detect(), so a script
--- with no extension is still known by its shebang.
+-- The first line goes along to detect(), so a script with no extension is
+-- still known by its shebang.
 local function lexer_for(name, text)
-	local ok, lang = pcall(scintillua.detect, name, string.match(text, "^[^\n]*"))
-	if not ok or not lang then
-		return nil
-	end
-	local loaded, lexer = pcall(scintillua.load, lang)
-	return loaded and lexer or nil
+	local lang = scintillua.detect(name, string.match(text, "^[^\n]*"))
+	return lang and scintillua.load(lang)
 end
 
 local function highlight(text)
@@ -169,8 +163,8 @@ local function highlight(text)
 	if not lexer then
 		return nil
 	end
-	local ok, tokens = pcall(lexer.lex, lexer, text)
-	if not ok or type(tokens) ~= "table" then
+	local tokens = lexer:lex(text)
+	if type(tokens) ~= "table" then
 		return nil
 	end
 	local out = {}
@@ -223,6 +217,9 @@ function filter_close()
 			scintillua = load_scintillua() or false
 		end
 		if scintillua then
+			-- Every step of highlight runs Scintillua's own Lua, and code
+			-- written for another version of it can raise, so a failure
+			-- anywhere there just leaves this file uncoloured.
 			local ok, marked = pcall(highlight, text)
 			if ok and marked then
 				html(marked)