Be lazy in reporting errors in the lexer

Instead of reporting an error with `.report(f(...))`, we now do
`.report(f, ...)`. This allows consumers to ignore error messages when
not needed, such as when just doing syntax highlighting.

projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/init.lua

@@ -21,6 +21,8 @@ local error_printer = require "cc.internal.error_printer"
 local error_sentinel = {}
 
 local function make_context(input)
+    expect(1, input, "string")
+
     local context = {}
 
     local lines = { 1 }
@@ -73,8 +75,9 @@ local function parse(input, start_symbol)
     expect(2, start_symbol, "number")
 
     local context = make_context(input)
-    function context.report(msg)
-        expect(1, msg, "table")
+    function context.report(msg, ...)
+        expect(1, msg, "table", "function")
+        if type(msg) == "function" then msg = msg(...) end
         error_printer(context, msg)
         error(error_sentinel)
     end
@@ -110,8 +113,9 @@ local function parse_repl(input)
     local context = make_context(input)
 
     local last_error = nil
-    function context.report(msg)
-        expect(1, msg, "table")
+    function context.report(msg, ...)
+        expect(1, msg, "table", "function")
+        if type(msg) == "function" then msg = msg(...) end
         last_error = msg
         error(error_sentinel)
     end

projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/lexer.lua

@@ -96,7 +96,7 @@ local function lex_number(context, str, start)
     local contents = sub(str, start, pos - 1)
     if not tonumber(contents) then
         -- TODO: Separate error for "2..3"?
-        context.report(errors.malformed_number(start, pos - 1))
+        context.report(errors.malformed_number, start, pos - 1)
     end
 
     return tokens.NUMBER, pos - 1
@@ -118,14 +118,14 @@ local function lex_string(context, str, start_pos, quote)
             return tokens.STRING, pos
         elseif c == "\n" or c == "\r" or c == "" then
             -- We don't call newline here, as that's done for the next token.
-            context.report(errors.unfinished_string(start_pos, pos, quote))
+            context.report(errors.unfinished_string, start_pos, pos, quote)
             return tokens.STRING, pos - 1
         elseif c == "\\" then
             c = sub(str, pos + 1, pos + 1)
             if c == "\n" or c == "\r" then
                 pos = newline(context, str, pos + 1, c)
             elseif c == "" then
-                context.report(errors.unfinished_string_escape(start_pos, pos, quote))
+                context.report(errors.unfinished_string_escape, start_pos, pos, quote)
                 return tokens.STRING, pos
             elseif c == "z" then
                 pos = pos + 2
@@ -133,7 +133,7 @@ local function lex_string(context, str, start_pos, quote)
                     local next_pos, _, c  = find(str, "([%S\r\n])", pos)
 
                     if not next_pos then
-                        context.report(errors.unfinished_string(start_pos, #str, quote))
+                        context.report(errors.unfinished_string, start_pos, #str, quote)
                         return tokens.STRING, #str
                     end
 
@@ -196,7 +196,7 @@ local function lex_long_str(context, str, start, len)
         elseif c == "[" then
             local ok, boundary_pos = lex_long_str_boundary(str, pos + 1, "[")
             if ok and boundary_pos - pos == len and len == 1 then
-                context.report(errors.nested_long_str(pos, boundary_pos))
+                context.report(errors.nested_long_str, pos, boundary_pos)
             end
 
             pos = boundary_pos
@@ -238,12 +238,12 @@ local function lex_token(context, str, pos)
             local end_pos = lex_long_str(context, str, boundary_pos + 1, boundary_pos - pos)
             if end_pos then return tokens.STRING, end_pos end
 
-            context.report(errors.unfinished_long_string(pos, boundary_pos, boundary_pos - pos))
+            context.report(errors.unfinished_long_string, pos, boundary_pos, boundary_pos - pos)
             return tokens.ERROR, #str
         elseif pos + 1 == boundary_pos then -- Just a "["
             return tokens.OSQUARE, pos
         else -- Malformed long string, for instance "[="
-            context.report(errors.malformed_long_string(pos, boundary_pos, boundary_pos - pos))
+            context.report(errors.malformed_long_string, pos, boundary_pos, boundary_pos - pos)
             return tokens.ERROR, boundary_pos
         end
 
@@ -260,7 +260,7 @@ local function lex_token(context, str, pos)
                 local end_pos = lex_long_str(context, str, boundary_pos + 1, boundary_pos - comment_pos)
                 if end_pos then return tokens.COMMENT, end_pos end
 
-                context.report(errors.unfinished_long_comment(pos, boundary_pos, boundary_pos - comment_pos))
+                context.report(errors.unfinished_long_comment, pos, boundary_pos, boundary_pos - comment_pos)
                 return tokens.ERROR, #str
             end
         end
@@ -317,18 +317,18 @@ local function lex_token(context, str, pos)
         if end_pos - pos <= 3 then
             local contents = sub(str, pos, end_pos)
             if contents == "&&" then
-                context.report(errors.wrong_and(pos, end_pos))
+                context.report(errors.wrong_and, pos, end_pos)
                 return tokens.AND, end_pos
             elseif contents == "||" then
-                context.report(errors.wrong_or(pos, end_pos))
+                context.report(errors.wrong_or, pos, end_pos)
                 return tokens.OR, end_pos
             elseif contents == "!=" or contents == "<>" then
-                context.report(errors.wrong_ne(pos, end_pos))
+                context.report(errors.wrong_ne, pos, end_pos)
                 return tokens.NE, end_pos
             end
         end
 
-        context.report(errors.unexpected_character(pos))
+        context.report(errors.unexpected_character, pos)
         return tokens.ERROR, end_pos
     end
 end

projects/core/src/main/resources/data/computercraft/lua/rom/modules/main/cc/internal/syntax/parser.lua

@@ -244,7 +244,7 @@ local function handle_error(context, stack, stack_n, token, token_start, token_e
         end
     end
 
-    context.report(errors.unexpected_token(token, token_start, token_end))
+    context.report(errors.unexpected_token, token, token_start, token_end)
     return false
 end
 

projects/core/src/test/resources/test-rom/spec/modules/cc/internal/syntax/syntax_helpers.lua

@@ -49,8 +49,9 @@ local function capture_parser(input, print_tokens, start)
     end
 
     local context = make_context(input)
-    function context.report(message)
-        expect(3, message, "table")
+    function context.report(message, ...)
+        expect(3, message, "table", "function")
+        if type(message) == "function" then message = message(...) end
 
         for _, msg in ipairs(message) do
             if type(msg) == "table" and msg.tag == "annotate" then