1 files changed, 123 insertions, 0 deletions
diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 0000000..fcb2db0
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,123 @@
+/*
+	Copyright 2023-2024 Gabriel Bjørnager Jensen.
+
+	This file is part of eAS.
+
+	eAS is free software: you can redistribute it
+	and/or modify it under the terms of the GNU
+	General Public License as published by the Free
+	Software Foundation, either version 3 of the
+	License, or (at your option) any later version.
+
+	eAS is distributed in the hope that it will
+	be useful, but WITHOUT ANY WARRANTY; without
+	even the implied warranty of MERCHANTABILITY or
+	FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+	General Public License for more details.
+
+	You should have received a copy of the GNU
+	General Public License along with eAS. If not,
+	see <https://www.gnu.org/licenses/>.
+*/
+
+use crate::source_location::SourceLocation;
+
+// e0??? | Syntax errors
+// e1??? | CLI errors
+// e2??? | Internal errors
+
+#[derive(Clone)]
+pub enum Error {
+	EndOfFile(             String),
+	UnknownMnemonic(       String, SourceLocation),
+	AccessDenied(          String),
+	IllegalCharacter(      char, SourceLocation),
+	IncompleteNode(        SourceLocation),
+	InvalidShortParameter( char),
+	MissingInputFile,
+	MissingTargetProcessor,
+	UnterminatedString(    SourceLocation),
+	MissingShortValue(     char),
+	InvalidTargetFormat(   String),
+	InvalidTargetProcessor(String),
+	InvalidLongParameter(  String),
+	MissingLongValue(      String),
+	MissingShortArgument,
+	InvalidFileEncoding(   String),
+	MissingLongArgument,
+}
+
+impl Error {
+	#[must_use]
+	pub const fn code(&self) -> u16 {
+		use Error::*;
+
+		return match *self {
+			EndOfFile(             ..) => 0x0000,
+			UnknownMnemonic(       ..) => 0x0001,
+			IllegalCharacter(      ..) => 0x0002,
+			IncompleteNode(        ..) => 0x0003,
+			UnterminatedString(    ..) => 0x0004,
+
+			InvalidShortParameter( ..) => 0x1000,
+			MissingInputFile           => 0x1001,
+			MissingTargetProcessor     => 0x1002,
+			MissingShortValue(     ..) => 0x1003,
+			InvalidTargetFormat(   ..) => 0x1004,
+			InvalidTargetProcessor(..) => 0x1005,
+			InvalidLongParameter(  ..) => 0x1006,
+			MissingLongValue(      ..) => 0x1007,
+			MissingShortArgument       => 0x1008,
+			InvalidFileEncoding(   ..) => 0x1009,
+			MissingLongArgument        => 0x100A,
+
+			AccessDenied(          ..) => 0x2000,
+		};
+	}
+
+	#[must_use]
+	pub fn message(&self) -> String {
+		use Error::*;
+
+		return match *self {
+			AccessDenied(          ref f)    => format!("access denied to \"{f}\""),
+			EndOfFile(             _)        => String::from("end of file"),
+			IllegalCharacter(      c, _)     => format!("illegal character U+{:04X} '{c}'", c as u32),
+			IncompleteNode(        _)        => format!("incomplete node"),
+			InvalidFileEncoding(   ref s)    => format!("invalid file encoding \"{s}\""),
+			InvalidLongParameter(  ref s)    => format!("invalid target processor `--{s}`"),
+			InvalidShortParameter( c)        => format!("invalid short parameter `-{c}`"),
+			InvalidTargetFormat(   ref s)    => format!("invalid target format \"{s}\""),
+			InvalidTargetProcessor(ref s)    => format!("invalid target processor \"{s}\""),
+			MissingInputFile                 => String::from("missing input file"),
+			MissingLongArgument              => String::from("missing long argument after `--"),
+			MissingLongValue(      ref s)    => format!("missing value for long parameter `--{s}`"),
+			MissingShortArgument             => format!("missing short parameter after `-`"),
+			MissingShortValue(     c)        => format!("missing value for short parameter `-{c}`"),
+			MissingTargetProcessor           => String::from("missing target processor"),
+			UnknownMnemonic(       ref s, _) => format!("invalid mnemonic {s}"),
+			UnterminatedString(    _)        => format!("unterminated string"),
+		};
+	}
+
+	#[must_use]
+	pub fn note(&self) -> Option<String> {
+		use Error::*;
+
+		return match *self {
+			EndOfFile(         ref f)     => Some(format!("consider adding an END directive to \"{f}\"")),
+			IllegalCharacter(  _,  ref l) => Some(format!("{l}")),
+			IncompleteNode(    ref l)     => Some(format!("{l}")),
+			UnknownMnemonic(   _,  ref l) => Some(format!("{l}")),
+			UnterminatedString(ref l)     => Some(format!("found string delimiter {l}")),
+
+			| InvalidTargetFormat(   _)
+			| InvalidTargetProcessor(_)
+			| MissingLongArgument
+			| MissingShortArgument
+			=> Some(String::from("see `eas -h` or refer to the manual for more information")),
+
+			_ => None,
+		};
+	}
+}