More parser implementation

vasm/src/main.rs

@@ -3,7 +3,6 @@ extern crate pest;
 extern crate pest_derive;
 
 mod parse_error;
-mod vasm_line;
 mod vasm_parser;
 
 fn main() {

vasm/src/parse_error.rs

@@ -1,10 +1,26 @@
-use vcore::opcodes::InvalidOpcode;
+use vcore::opcodes::{InvalidMnemonic};
+use pest::iterators::Pair;
+use std::fmt::{Display, Formatter};
+use crate::vasm_parser::Rule;
 
 #[derive(Debug, PartialEq)]
-pub struct ParseError<'a>(pub &'a str);
+pub enum ParseError<'a> {
+    LineParseFailure,
+    InvalidInstruction(&'a str)
+}
 
-impl<'a> From<InvalidOpcode> for ParseError<'a> {
-    fn from(_: InvalidOpcode) -> Self {
-        Self("Invalid opcode")
+impl<'a> From<InvalidMnemonic<'a>> for ParseError<'a> {
+    fn from(err: InvalidMnemonic<'a>) -> Self {
+        Self::InvalidInstruction(err.0)
     }
 }
+
+impl<'a> Display for ParseError<'a> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        use ParseError::*;
+        match self {
+            LineParseFailure => write!(f, "Failed to parse line"),
+            InvalidInstruction(p) => write!(f, "Cannot parse {} as instruction", p)
+        }
+    }
+}

vasm/src/vasm.pest

@@ -16,8 +16,9 @@ dec_number = @{ ASCII_NONZERO_DIGIT ~ ASCII_DIGIT* }
 neg_number = ${ "-" ~ dec_number }
 hex_number = ${ "0x" ~ ASCII_HEX_DIGIT+ }
 bin_number = ${ "0b" ~ ASCII_BIN_DIGIT+ }
+oct_number = ${ "0o" ~ ASCII_OCT_DIGIT+ }
 dec_zero = @{ "0" }
-number = { dec_number | hex_number | bin_number | dec_zero | neg_number }
+number = { dec_number | hex_number | bin_number | oct_number | dec_zero | neg_number }
 
 // A label can be any sequence of C-identifier-y characters, as long as it doesn't start with
 // a digit:
@@ -63,13 +64,11 @@ string = ${ "\"" ~ string_inner* ~ "\"" }
 // However, most of these elements are optional. An opcode is only required if an
 // argument exists. Comments are already handled by the COMMENT pattern
 
-
 // Some sub-patterns for the portions of a line:
 label_group = { label ~ ":" }
-argument_group = { expr | string }
 
 // An opcode might be an actual opcode, or a directive
-instruction_group = { (opcode | directive) ~ argument_group? }
+instruction_group = { (opcode | directive) ~ (expr | string)? }
 
 // Finally the entire pattern for an assembly line:
 line = { SOI ~ label_group? ~ instruction_group? ~ EOI }

vasm/src/vasm_line.rs

@@ -1,61 +0,0 @@
-use vcore::opcodes::Opcode;
-
-#[derive(Debug, PartialEq, Copy, Clone)]
-pub enum Directive { Db, Equ, Org }
-
-impl From<&str> for Directive {
-    fn from(value: &str) -> Self {
-        use Directive::*;
-        match value {
-            ".db" => Db,
-            ".equ" => Equ,
-            ".org" => Org,
-            _ => unreachable!()
-        }
-    }
-}
-
-#[derive(Debug, PartialEq, Copy, Clone)]
-pub struct VASMLine<'a> {
-    label: Option<&'a str>,
-    opcode: Option<Opcode>,
-    directive: Option<Directive>
-}
-
-impl<'a> VASMLine<'a> {
-    pub fn blank() -> VASMLine<'a> {
-        VASMLine {
-            label: None,
-            opcode: None,
-            directive: None
-        }
-    }
-
-    pub fn for_opcode(opcode: Opcode) -> VASMLine<'a> {
-        Self::blank().with_opcode(opcode)
-    }
-
-    pub fn with_opcode(self, opcode: Opcode) -> VASMLine<'a> {
-        VASMLine {
-            label: self.label,
-            opcode: Some(opcode),
-            directive: self.directive
-        }
-    }
-
-    pub fn with_directive(self, directive: Directive) -> VASMLine<'a> {
-        VASMLine {
-            label: self.label,
-            opcode: self.opcode,
-            directive: Some(directive)
-        }
-    }
-
-    pub fn with_label(self, label: &'a str) -> Self {
-        VASMLine {
-            label: Some(label),
-            opcode: self.opcode,
-            directive: self.directive
-        }
-    }
-}

vasm/src/vasm_parser.rs

@@ -1,18 +1,167 @@
 use vcore::opcodes::Opcode;
 
 use crate::parse_error::ParseError;
-use crate::vasm_line::{Directive, VASMLine};
 
 use pest::{Parser};
 use std::convert::TryFrom;
+use pest::iterators::Pair;
+use std::str::FromStr;
 
 #[derive(Parser)]
 #[grammar = "vasm.pest"]
 struct VASMParser;
 
+#[derive(Debug, PartialEq, Copy, Clone)]
+pub enum Directive { Db, Equ, Org }
+
+impl From<&str> for Directive {
+    fn from(value: &str) -> Self {
+        use Directive::*;
+        match value {
+            ".db" => Db,
+            ".equ" => Equ,
+            ".org" => Org,
+            _ => unreachable!()
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Copy, Clone)]
+pub enum Instruction {
+    Directive(Directive),
+    Opcode(Opcode)
+}
+
+impl<'a> TryFrom<Pair<'a, Rule>> for Instruction {
+    type Error = ParseError<'a>;
+
+    fn try_from(pair: Pair<'a, Rule>) -> Result<Self, Self::Error> {
+        match pair.as_rule() {
+            Rule::opcode => Ok(Instruction::Opcode(Opcode::try_from(pair.as_str())?)),
+            Rule::directive => Ok(Instruction::Directive(Directive::from(pair.as_str()))),
+            _ => Err(ParseError::InvalidInstruction(pair.as_str()))
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Copy, Clone)]
+enum Operator { Add, Sub, Mul, Div, Mod }
+
+#[derive(Debug, PartialEq, Clone)]
+enum Node<'a>{
+    Number(i32),
+    Label(&'a str),
+    String(String),
+    Expr(Box<Node<'a>>, Vec<(Operator, Node<'a>)>)
+}
+
+impl<'a> Node<'a> {
+    pub fn simple_expr(node: Node<'a>) -> Node<'a> {
+        Node::Expr(Box::from(node), vec![])
+    }
+
+    pub fn string(pair: Pair<'a, Rule>) -> Node<'a> {
+        let mut string = String::with_capacity(pair.as_str().len());
+        for inner in pair.into_inner() {
+            let string_inner = inner.as_str();
+            match string_inner {
+                "\\t" => string.push_str("\t"),
+                "\\r" => string.push_str("\r"),
+                "\\n" => string.push_str("\n"),
+                "\\0" => string.push_str("\0"),
+                "\\\\" => string.push_str("\\"),
+                "\\\"" => string.push_str("\""),
+                _ => string.push_str(string_inner)
+            }
+        }
+        Node::String(string)
+    }
+}
+
+impl<'a> TryFrom<Pair<'a, Rule>> for Node<'a> {
+    type Error = ParseError<'a>;
+
+    fn try_from(pair: Pair<'a, Rule>) -> Result<Self, Self::Error> {
+        match pair.as_rule() {
+            Rule::expr | Rule::term => {
+                let first = Node::try_from(pair.into_inner().next().unwrap())?;
+                Ok(Node::Expr(Box::from(first), vec![]))
+            }
+            Rule::fact | Rule::number => {
+                Ok(Node::try_from(pair.into_inner().next().unwrap())?)
+            }
+            Rule::dec_number | Rule::dec_zero | Rule::neg_number => {
+                Ok(Node::Number(i32::from_str(pair.as_str()).unwrap()))
+            }
+            Rule::hex_number => { Ok(Node::Number(i32::from_str_radix(pair.as_str().get(2..).unwrap(), 16).unwrap())) }
+            Rule::bin_number => { Ok(Node::Number(i32::from_str_radix(pair.as_str().get(2..).unwrap(), 2).unwrap())) }
+            Rule::oct_number => { Ok(Node::Number(i32::from_str_radix(pair.as_str().get(2..).unwrap(), 8).unwrap())) }
+            Rule::string => { Ok(Node::string(pair)) }
+            _ => todo!()
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Clone)]
+pub struct VASMLine<'a> {
+    label: Option<&'a str>,
+    instruction: Option<Instruction>,
+    argument: Option<Node<'a>>
+}
+
+impl<'a> VASMLine<'a> {
+    pub fn blank() -> VASMLine<'a> {
+        VASMLine {
+            label: None,
+            instruction: None,
+            argument: None
+        }
+    }
+
+    pub fn with_instruction(self, instruction: Instruction) -> VASMLine<'a> {
+        VASMLine {
+            label: self.label,
+            instruction: Some(instruction),
+            argument: self.argument
+        }
+    }
+
+    pub fn with_opcode(self, opcode: Opcode) -> VASMLine<'a> {
+        VASMLine {
+            label: self.label,
+            instruction: Some(Instruction::Opcode(opcode)),
+            argument: self.argument
+        }
+    }
+
+    pub fn with_directive(self, directive: Directive) -> VASMLine<'a> {
+        VASMLine {
+            label: self.label,
+            instruction: Some(Instruction::Directive(directive)),
+            argument: self.argument
+        }
+    }
+
+    pub fn with_label(self, label: &'a str) -> Self {
+        VASMLine {
+            label: Some(label),
+            instruction: self.instruction,
+            argument: self.argument
+        }
+    }
+
+    pub fn with_argument(self, argument: Node<'a>) -> Self {
+        VASMLine {
+            label: self.label,
+            instruction: self.instruction,
+            argument: Some(argument)
+        }
+    }
+}
+
 fn parse_vasm_line(line: &str) -> Result<VASMLine, ParseError<'_>> {
     let mut pairs = VASMParser::parse(Rule::line, line)
-        .map_err(|_| ParseError("Failed to parse line"))?
+        .map_err(|_| ParseError::LineParseFailure)?
         .next()
         .unwrap()
         .into_inner()
@@ -26,13 +175,16 @@ fn parse_vasm_line(line: &str) -> Result<VASMLine, ParseError<'_>> {
     }
 
     if let Some(instruction_group) = pairs.next_if(|pair| pair.as_rule() == Rule::instruction_group) {
-        let instruction_field = instruction_group.into_inner().next().unwrap();
-        vasm_line = match instruction_field.as_rule() {
-            Rule::opcode => vasm_line.with_opcode(Opcode::try_from(instruction_field.as_str())?),
-            Rule::directive => vasm_line.with_directive(Directive::from(instruction_field.as_str())),
-            _ => unreachable!()
+        let mut pairs = instruction_group.into_inner();
+        vasm_line = vasm_line.with_instruction(Instruction::try_from(pairs.next().unwrap())?);
+
+        if let Some(argument_group) = pairs.next() {
+            vasm_line = match argument_group.as_rule() {
+                Rule::string => vasm_line.with_argument(Node::try_from(argument_group)?),
+                Rule::expr => vasm_line.with_argument(Node::try_from(argument_group.into_inner().next().unwrap())?),
+                _ => unreachable!()
+            }
         }
-        // something something argument here
     }
 
     Ok(vasm_line)
@@ -41,23 +193,57 @@ fn parse_vasm_line(line: &str) -> Result<VASMLine, ParseError<'_>> {
 #[cfg(test)]
 mod test {
     use super::*;
+    use Opcode::*;
+    use Directive::*;
+
+    impl<'a> VASMLine<'a> {
+        pub fn op(opcode: Opcode) -> VASMLine<'a> {
+            Self::blank().with_opcode(opcode)
+        }
+
+        fn op_number(opcode: Opcode, argument: i32) -> VASMLine<'a> {
+            Self::blank().with_opcode(opcode).with_argument(Node::simple_expr(Node::Number(argument)))
+        }
+
+        pub fn dir_str(directive: Directive, string: &str) -> VASMLine<'a> {
+            Self::blank().with_directive(directive).with_argument(Node::String(string.to_string()))
+        }
+    }
 
     #[test]
     fn test_parse() {
-        assert_eq!(parse_vasm_line("add"), Ok(VASMLine::for_opcode(Opcode::Add)));
-        assert_eq!(parse_vasm_line("sub"), Ok(VASMLine::for_opcode(Opcode::Sub)));
-        assert_eq!(parse_vasm_line("blah"), Err(ParseError("Invalid opcode")));
+        assert_eq!(parse_vasm_line("add"), Ok(VASMLine::op(Add)));
+        assert_eq!(parse_vasm_line("sub"), Ok(VASMLine::op(Sub)));
+        assert_eq!(parse_vasm_line("blah"), Err(ParseError::InvalidInstruction("blah")));
+        assert_eq!(parse_vasm_line("47"), Err(ParseError::LineParseFailure));
+    }
+
+    #[test]
+    fn test_numbers() {
+        assert_eq!(parse_vasm_line("add 45"), Ok(VASMLine::op_number(Add, 45)));
+        assert_eq!(parse_vasm_line("add 0"), Ok(VASMLine::op_number(Add, 0)));
+        assert_eq!(parse_vasm_line("add 0x10"), Ok(VASMLine::op_number(Add, 16)));
+        assert_eq!(parse_vasm_line("add 0b1111"), Ok(VASMLine::op_number(Add, 15)));
+        assert_eq!(parse_vasm_line("add 0o377"), Ok(VASMLine::op_number(Add, 255)));
+        assert_eq!(parse_vasm_line("add -17"), Ok(VASMLine::op_number(Add, -17)));
+    }
+
+    #[test]
+    fn test_strings() {
+        assert_eq!(parse_vasm_line(".db \"blah\""), Ok(VASMLine::dir_str(Db, "blah")));
+        assert_eq!(parse_vasm_line(".db \"blah\\twith escapes\\0\""), Ok(VASMLine::dir_str(Db, "blah\twith escapes\0")))
     }
 
     #[test]
     fn test_parse_labels() {
-        assert_eq!(parse_vasm_line("foo: add"), Ok(VASMLine::for_opcode(Opcode::Add).with_label("foo")));
+        assert_eq!(parse_vasm_line("foo: add"), Ok(VASMLine::op(Add).with_label("foo")));
         assert_eq!(parse_vasm_line("bar:"), Ok(VASMLine::blank().with_label("bar")));
+        assert_eq!(parse_vasm_line("foo: add 43"), Ok(VASMLine::op_number(Add, 43).with_label("foo")));
     }
 
     #[test]
     fn test_parse_directives() {
-        assert_eq!(parse_vasm_line("foo: .equ"), Ok(VASMLine::blank().with_label("foo").with_directive(Directive::Equ)));
-        assert_eq!(parse_vasm_line(".db"), Ok(VASMLine::blank().with_directive(Directive::Db)));
+        assert_eq!(parse_vasm_line("foo: .equ"), Ok(VASMLine::blank().with_label("foo").with_directive(Equ)));
+        assert_eq!(parse_vasm_line(".db"), Ok(VASMLine::blank().with_directive(Db)));
     }
 }

vcore/src/opcodes.rs

@@ -59,6 +59,9 @@ impl Display for InvalidOpcode {
 
 impl std::error::Error for InvalidOpcode {}
 
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct InvalidMnemonic<'a>(pub &'a str);
+
 impl Display for Opcode {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -163,10 +166,10 @@ impl TryFrom<u8> for Opcode {
     }
 }
 
-impl TryFrom<&str> for Opcode {
-    type Error = InvalidOpcode;
+impl<'a> TryFrom<&'a str> for Opcode {
+    type Error = InvalidMnemonic<'a>;
 
-    fn try_from(value: &str) -> Result<Self, Self::Error> {
+    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
         use Opcode::*;
         Ok(match value {
             "nop" => Nop,
@@ -212,7 +215,7 @@ impl TryFrom<&str> for Opcode {
             "popr" => Popr,
             "peekr" => Peekr,
             "debug" => Debug,
-            _ => return Err(InvalidOpcode(255))
+            _ => return Err(InvalidMnemonic(value))
         })
     }
 }