Version 4.3.1

Author: informedcitizenry

Docs/CommandLineOptions.md

@@ -312,6 +312,15 @@ If any defined sections are not used, do not emit a warning.
     // do not warn if "zp" is never used
 ```
 
+**`--Wregister-as-identifier`**
+
+Warn when a constant, label, or variable shares the same name as a CPU register.
+
+```
+    .cpu "z80"
+    ix = 0
+```
+
 **`--Wsimplify-call-return`**
 
 If a return instruction immediately follows a call instruction, warn that the two instructions can be combined into a single jump instruction.

Docs/CommodoreControlCodes.md

@@ -229,12 +229,14 @@ The `.unamp` directive will delete the custom encoding for the codepoint or rang
 
 The assembler can be directed to encode string literals explicitly regardless of the active encoding, according to their prefix:
 
-| Prefix | Encoding | Example                            |
-|--------|----------|------------------------------------|
-| None   | Current  | `"HI" // by default 48 49`         |
-| `u8`   | UTF-8    | `u8"HI" // 48 49`                  |
-| `u`    | UTF-16   | `u"HI" // 48 00 49 00`             |
-| `U`    | UTF-32   | `U"HI" // 48 00 00 00 49 00 00 00` |
+| Prefix | Encoding                 | Example                            |
+|--------|--------------------------|------------------------------------|
+| None   | Current                  | `"HI" // by default 48 49`         |
+| `p`    | PETSCII                  | `p"HI" // c8 c9`                   |
+| `s`    | Commodore screen codes   | `s"HI" // 08 09`                   |
+| `u8`   | UTF-8                    | `u8"HI" // 48 49`                  |
+| `u`    | UTF-16                   | `u"HI" // 48 00 49 00`             |
+| `U`    | UTF-32                   | `U"HI" // 48 00 00 00 49 00 00 00` |
 
 #### Escape sequences
 
@@ -278,6 +280,36 @@ In the above example, the expression can be transformed with format specifiers:
         .string $"Start address: ${START:X4}" // Becomes "Start address: $C000"
 ```
 
+To represent a curly brace within the string itself, add an extra brace (`{` for left or `}` for right):
+
+        .string $"{{HI}}" // Becomes "{HI}"
+
+#### Commodore Control Codes
+
+For PETSCII and screen code encodings, the assembler also recognizes control codes found in program listings of various Commodore references and related magazines, such as [Compute's Gazette](https://archive.org/details/computes.gazette/Compute_Gazette_Issue_01_1983_Jul/):
+
+```
+    .string p"{CLR}{HOME}" // > 93 13
+    .encoding "cbmscreen"
+    .string "{SPACE}{UP ARROW}" // > 20 1e
+```
+
+If the string is an interpolated string, care must be taken in adding control codes since in interpolated strings curly braces mark the boundaries of interpolated expressions:
+
+```
+        .encoding "petscii"
+        .string $"{CLR}{HOME}{3+2}"
+```
+
+The above would give an error (or an unexpected result if `CLR` and `HOME` are labels). To fix that simply escape the braces themselves:
+
+```
+        .encoding "petscii"
+        .string $"{{CLR}}{{HOME}}{3+2}" // > 93 13 35
+```
+
+See [here](/Docs/CommodoreControlCodes.md) for a full listing of all valid control codes for these two encodings.
+
 #### Char Methods
 
 | Method name | Purpose                                     | Example                   |

Docs/Expressions.md

@@ -40,9 +40,9 @@ Like standard labels, anonymous labels can be used in expressions as well:
     lda (-) + 2,x // read second from offset from backward reference.
 ```
 
-# Constants and Variables
+## Constants and Variables
 
-## Constants
+### Constants
 
 Constants are symbols that, like labels, make it convenient to represent addresses or values referenced from other parts of code.
 
@@ -57,7 +57,7 @@ CHRIN .equ $ffcf
 
 Constants can be forward referenced, and can only be assigned once--as they are constant, their values cannot be changed.
 
-## Variables
+### Variables
 
 Variables are symbols assigned to values that can be changed as often as needed. The assignment `:=` operator can declares a new variable or re-assign the contents of an existing variable to a new value.
 
@@ -279,7 +279,7 @@ label   nop
 
 # Symbols and Reserved Words
 
-User-defined symbols cannot share with mnemonics and registers of the current target CPU, unless their case does not match and the assembler is set to case-sensitive. For instance, in 6502 mode all of the 56 6502 mnemonics and `a`, `x`, and `y` are reserved and cannot be used for label or constant names.
+User-defined symbols cannot share the same name as mnemonics of the current target CPU, unless their case does not match and the assembler is set to case-sensitive. For instance, in 6502 mode all of the 56 6502 mnemonics are reserved and cannot be used for label or constant names.
 
 ```
 lda nop // this would error "lda" cannot be used as a label
@@ -288,6 +288,16 @@ lda nop // this would error "lda" cannot be used as a label
 Lda nop // no error
 ```
 
+Symbols can share names with registers, but the presence of a register in an operand for a CPU instruction might cause an unexpected compilation result or even an error. To avoid this you would need to refactor the operand expression.
+
+```
+        a = 3
+        asl a // The assembler interprets 'a' not as an address but as 
+              // the accumulator register
+
+        asl a+0 // The assembler interprets 'a' as a constant (the address 3)
+```
+
 ## Other Topics
 
 * [Getting Started](/Docs/GettingStarted.md)

Docs/SymbolsAndScopes.md

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017-2023 informedcitizenry <[email protected]>
+Copyright (c) 2017-2024 informedcitizenry <[email protected]>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

LICENSE

@@ -1,6 +1,6 @@
 # 6502.Net, A .Net-Based Cross-Assembler for Several 8-Bit Microprocessors.
 
-Version 4.2.2
+Version 4.3.1
 
 ## Overview
 

README.md

@@ -1,5 +1,5 @@
 //-----------------------------------------------------------------------------
-// Copyright (c) 2017-2023 informedcitizenry <[email protected]>
+// Copyright (c) 2017-2024 informedcitizenry <[email protected]>
 //
 // Licensed under the MIT license. See LICENSE for full license information.
 // 

Sixty502DotNet.Shared/CodeGen/Architecture.cs

@@ -1,5 +1,5 @@
 //-----------------------------------------------------------------------------
-// Copyright (c) 2017-2023 informedcitizenry <[email protected]>
+// Copyright (c) 2017-2024 informedcitizenry <[email protected]>
 //
 // Licensed under the MIT license. See LICENSE for full license information.
 // 

Sixty502DotNet.Shared/CodeGen/CodeAnalysisContext.cs

@@ -1,5 +1,5 @@
 //-----------------------------------------------------------------------------
-// Copyright (c) 2017-2023 informedcitizenry <[email protected]>
+// Copyright (c) 2017-2024 informedcitizenry <[email protected]>
 //
 // Licensed under the MIT license. See LICENSE for full license information.
 // 

Sixty502DotNet.Shared/CodeGen/CodeOutput.cs

@@ -1,10 +1,10 @@
 //-----------------------------------------------------------------------------
-// Copyright (c) 2017-2023 informedcitizenry <[email protected]>
+// Copyright (c) 2017-2024 informedcitizenry <[email protected]>
 //
 // Licensed under the MIT license. See LICENSE for full license information.
 // 
 //-----------------------------------------------------------------------------
-
+
 using System.Text;
 
 namespace Sixty502DotNet.Shared;