Support variable declaration initializer

source/main.elna

@@ -183,44 +183,45 @@ proc lexer_escape(escape: Char, result: ^Char) -> Bool;
 var
   successful: Bool;
 begin
-  if escape = 'n' then
-    result^ := '\n';
-    successful := true
-  elsif escape = 'a' then
-    result^ := '\a';
-    successful := true
-  elsif escape = 'b' then
-    result^ := '\b';
-    successful := true
-  elsif escape = 't' then
-    result^ := '\t';
-    successful := true
-  elsif escape = 'f' then
-    result^ := '\f';
-    successful := true
-  elsif escape = 'r' then
-    result^ := '\r';
-    successful := true
-  elsif escape = 'v' then
-    result^ := '\v';
-    successful := true
-  elsif escape = '\\' then
-    result^ := '\\';
-    successful := true
-  elsif escape = '\'' then
-    result^ := '\'';
-    successful := true
-  elsif escape = '"' then
-    result^ := '"';
-    successful := true
-  elsif escape = '?' then
-    result^ := '\?';
-    successful := true
-  elsif escape = '0' then
-    result^ := '\0';
-    successful := true
-  else
-    successful := false
+  case escape of
+    'n':
+      result^ := '\n';
+      successful := true
+    | 'a':
+      result^ := '\a';
+      successful := true
+    | 'b':
+      result^ := '\b';
+      successful := true
+    | 't':
+      result^ := '\t';
+      successful := true
+    | 'f':
+      result^ := '\f';
+      successful := true
+    | 'r':
+      result^ := '\r';
+      successful := true
+    | 'v':
+      result^ := '\v';
+      successful := true
+    | '\\':
+      result^ := '\\';
+      successful := true
+    | '\'':
+      result^ := '\'';
+      successful := true
+    | '"':
+      result^ := '"';
+      successful := true
+    | '?':
+      result^ := '\?';
+      successful := true
+    | '0':
+      result^ := '\0';
+      successful := true
+    else
+      successful := false
   end;
   return successful
 end;
@@ -304,11 +305,9 @@ proc lexer_string(source_code: ^SourceCode, token_content: ^StringBuffer) -> Boo
 var
   token_end, constructed_string: ^Char;
   token_length: Word;
-  is_valid: Bool;
+  is_valid: Bool := true;
   next_char: Char;
 begin
-  is_valid := true;
-
   while is_valid & ~source_code_empty(source_code) & source_code_head(source_code^) <> '"' do
     is_valid := lexer_character(source_code, @next_char);
 
@@ -625,9 +624,8 @@ end;
 proc parse(tokens: ^Token, tokens_size: Word);
 var
   current_token: ^Token;
-  i: Word;
+  i: Word := 0;
 begin
-  i := 0u;
   while i < tokens_size do
     current_token := tokens + i;
 
@@ -787,11 +785,9 @@ end;
 
 proc compile_in_stages(command_line: ^CommandLine, source_code: SourceCode) -> Int;
 var
-  return_code: Int;
+  return_code: Int := 0;
   lexer: Tokenizer;
 begin
-  return_code := 0;
-
   if command_line^.lex or command_line^.parse then
     lexer := lexer_text(source_code)
   end;
@@ -808,11 +804,9 @@ var
   tokens_size: Word;
   source_code: SourceCode;
   command_line: ^CommandLine;
-  return_code: Int;
+  return_code: Int := 0;
   source_file: ^SourceFile;
 begin
-  return_code := 0;
-
   command_line := parse_command_line(argc, argv);
   if command_line = nil then
     return_code := 2