Documented FUNCTION in directives, added errors.md

docs/directives.md

@@ -81,6 +81,15 @@ Create a macro. When used with the command line option -endm the macro ends with
 	ENDM
 
 
+### FUNCTION
+
+A user function is a pre-defined one-line expression that can be used in a similar way as a macro, but instead of generating binary data it returns a single integer value.
+
+	; user defined function
+	FUNCTION alignto(address, alignment) (address + alignment-1) & (~alignment)
+
+Note that functions must evaluate at the time of reference, if any symbol is not evaluated it will fail. This differs from in-place expressions that can have references that will be evaluated at a later time in assembly or at link time.
+
 ### EVAL, PRINT, ECHO
 
 Print expression to stdout during assemble. The syntax is:

docs/errors.md

@@ -0,0 +1,175 @@
+# List of x65 error messages
+	
+## Undefined code
+
+Could not recognize code at this point in the file
+
+## Unexpected character in expression
+
+A character in an expression has confused the assembler evaluator
+
+## Too many values in expression
+
+There is a limit to the number of values encountered in a single expression, feel free to change that number if you must.
+
+## Too many operators in expression
+
+There is a limit to the number of operators encountered in a single expression, this can also be modified as needed.
+
+## Unbalanced right parenthesis in expression
+
+A right parenthesis without a corresponding left parenthesis was encountered in the expression
+
+## Expression operation
+
+The expression evaluator has confused itself with an unrecognized operator.
+
+## Expression missing values
+
+Not enough values to complete an expression operator
+
+## Instruction can not be zero page
+
+An attempt to force a zero page command that does not support it was foiled by the assembler.
+
+## Invalid addressing mode for instruction
+
+Indeed!
+
+## Internal label organization mishap
+
+Internal error
+
+## Bad addressing mode
+
+Don't be bad
+
+## Unexpected character in addressing mode
+
+What gives?
+
+## Unexpected label assignment format
+
+Equal sign or EQU is desired for assigning const or mutable (LABEL) labels.
+
+## Changing value of label that is constant
+
+You declared that you would not change your mind but you did. I can't deal with it.
+
+## Out of labels in pool
+
+A label pool was declared at a certain size that has now been exceeded.
+
+## Internal label pool release confusion
+
+Internal error
+
+## Label pool range evaluation failed
+
+Could not determine the range for the label pool at the current line of assembly
+
+## Label pool was redeclared within its scope
+
+No recursive pool dipping please.
+
+## Pool label already defined
+
+Once is enough
+
+## Struct already defined
+
+Don't repeat yourself
+
+## Referenced struct not found
+
+But specify it at least once.
+
+## Declare constant type not recognized (dc.?)
+
+Specify word size using something that can be understood
+
+## rept count expression could not be evaluated
+
+The count needs to be evaluated at the current line of assembly
+
+## hex must be followed by an even number of hex numbers
+
+## DS directive failed to evaluate immediately
+
+The count needs to be evaluated at the current line of assembly
+
+## File is not a valid x65 object file
+
+A file that was referenced with an INCOBJ directive was not recognized as a valid x65 object file
+
+## Failed to read include file
+## Using symbol PULL without first using a PUSH
+
+Withdrawing beyond your deposits amounts to robbery.
+
+## User invoked error
+
+An ABORT or ERR directive was assembled
+
+## Errors after this point will stop execution
+
+This is a placeholder error message
+
+## Branch is out of range
+
+Max branch distance was exceeded at this point in assembly
+
+## Function declaration is missing name or expression
+
+A FUNCTION directive requires a name, open/close parenthesis and an expression. Parameters within the parenthesis is optional.
+
+## Function could not resolve the expression
+
+The expression could not be evaluated at this point in assembly
+
+## Expression evaluateion recursion too deep
+## Target address must evaluate immediately for this operation
+## Scoping is too deep
+## Unbalanced scope closure
+## Unexpected macro formatting
+## Align must evaluate immediately
+## Out of memory for macro expansion
+
+Your memory is not enough
+
+## Problem with macro argument
+## Conditional could not be resolved
+## #endif encountered outside conditional block
+
+ENDIF directive without an IF or equivalent
+
+## #else or #elif outside conditional block
+
+ELSE or ELIF directive without an IF or equivalent
+
+## Struct can not be assembled as is
+## Enum can not be assembled as is
+## Conditional assembly (#if/#ifdef) was not terminated in file or macro
+
+an IF or equivalent does not have a matching ENDIF directive
+
+## rept is missing a scope ('{ ... }')
+
+You want me to repeat what exactly?
+
+## Link can only be used in a fixed address section
+## Link can not be used in dummy sections
+## Can not process this line
+## Unexpected target offset for reloc or late evaluation
+## CPU is not supported
+## Can't append sections
+## Zero page / Direct page section out of range
+## Attempting to assign an address to a non-existent section
+## Attempting to assign an address to a fixed address section
+## Can not link a zero page section with a non-zp section
+## Out of memory while building
+## Can not write to file
+## Assembly aborted
+## Condition too deeply nested
+
+There is a limit to the number of IFs within IFs.

docs/readme.md

@@ -58,3 +58,7 @@ See [Eval Functions](eval_functions.md)
 Some info about the included example x65macro.i file.
 
 See [Macro Samples](macro_samples.md)
+
+## List of Errors
+
+See [Error List](errors.md)