Files
grassmudhorse.rs/src/parser.rs
2020-05-08 08:24:35 +08:00

216 lines
7.8 KiB
Rust

use super::err::*;
use super::ins::*;
pub const VALID_INSTRUCTION_CHARS: &str = "草泥马河蟹";
#[derive(Debug)]
enum InsId {
Push, // has data
Dup,
CopyN, // has data
Swap,
Pop,
PopN, // has data
Add,
Sub,
Mul,
Div,
Mod,
Store,
Retrieve,
DefineLabel, // has data
CallAtLabel, // has data
GotoLabel, // has data
GotoLabelE0, // has data
GotoLabelL0, // has data
ReturnCallAt,
End,
StdOutChar,
StdOutNum,
StdInChar,
StdInNum,
}
impl InsId {
fn has_data(&self) -> bool {
match self {
InsId::Push | InsId::CopyN | InsId::PopN |
InsId::DefineLabel | InsId::CallAtLabel |
InsId::GotoLabel | InsId::GotoLabelE0 | InsId::GotoLabelL0 => true,
_ => false,
}
}
fn new_instruction(&self, data: Option<isize>) -> Instruction {
match self {
InsId::Push => Instruction::Push(data.unwrap_or(0)),
InsId::Dup => Instruction::Dup,
InsId::CopyN => Instruction::CopyN(data.unwrap_or(0)),
InsId::Swap => Instruction::Swap,
InsId::Pop => Instruction::Pop,
InsId::PopN => Instruction::PopN(data.unwrap_or(0)),
InsId::Add => Instruction::Add,
InsId::Sub => Instruction::Sub,
InsId::Mul => Instruction::Mul,
InsId::Div => Instruction::Div,
InsId::Mod => Instruction::Mod,
InsId::Store => Instruction::Store,
InsId::Retrieve => Instruction::Retrieve,
InsId::DefineLabel => Instruction::DefineLabel(data.unwrap_or(0)),
InsId::CallAtLabel => Instruction::CallAtLabel(data.unwrap_or(0)),
InsId::GotoLabel => Instruction::GotoLabel(data.unwrap_or(0)),
InsId::GotoLabelE0 => Instruction::GotoLabelE0(data.unwrap_or(0)),
InsId::GotoLabelL0 => Instruction::GotoLabelL0(data.unwrap_or(0)),
InsId::ReturnCallAt => Instruction::ReturnCallAt,
InsId::End => Instruction::End,
InsId::StdOutChar => Instruction::StdOutChar,
InsId::StdOutNum => Instruction::StdOutNum,
InsId::StdInChar => Instruction::StdInChar,
InsId::StdInNum => Instruction::StdInNum,
}
}
}
#[derive(Debug)]
enum InsType {
Path(InsColl),
Node(InsId),
}
#[derive(Debug)]
struct Ins {
c: char,
ins_type: InsType,
}
#[derive(Debug)]
struct InsColl {
inses: Vec<Ins>,
}
pub fn parse_lang(lang: &str) -> Result<Vec<Instruction>, ParseError> {
let mut r = vec![];
let instruction_tree_root = make_instruction_tree();
let mut cs = lang.chars().filter(|c| {
VALID_INSTRUCTION_CHARS.chars().any(|vic| vic == *c)
});
loop {
match match_instruction(&instruction_tree_root, &mut cs) {
Err(err) => return Err(err),
Ok(None) => break,
Ok(Some(ins)) => r.push(ins),
}
}
Ok(r)
}
fn make_instruction_tree() -> InsColl {
InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::Push) },
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::Dup) },
Ins{ c: '', ins_type: InsType::Node(InsId::Swap) },
Ins{ c: '', ins_type: InsType::Node(InsId::Pop) }
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::CopyN) },
Ins{ c: '', ins_type: InsType::Node(InsId::PopN) }
]})},
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::Add) },
Ins{ c: '', ins_type: InsType::Node(InsId::Sub) },
Ins{ c: '', ins_type: InsType::Node(InsId::Mul) },
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::Div) },
Ins{ c: '', ins_type: InsType::Node(InsId::Mod) },
]})},
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::Store) },
Ins{ c: '', ins_type: InsType::Node(InsId::Retrieve) },
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::StdOutChar) },
Ins{ c: '', ins_type: InsType::Node(InsId::StdOutNum) },
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::StdInChar) },
Ins{ c: '', ins_type: InsType::Node(InsId::StdInNum) },
]})},
]})},
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::DefineLabel) },
Ins{ c: '', ins_type: InsType::Node(InsId::CallAtLabel) },
Ins{ c: '', ins_type: InsType::Node(InsId::GotoLabel) },
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::GotoLabelE0) },
Ins{ c: '', ins_type: InsType::Node(InsId::GotoLabelL0) },
Ins{ c: '', ins_type: InsType::Node(InsId::ReturnCallAt) },
]})},
Ins{ c: '', ins_type: InsType::Path(InsColl{ inses: vec![
Ins{ c: '', ins_type: InsType::Node(InsId::End) },
]})},
]})},
]}
}
fn match_instruction(ins_coll: &InsColl, cs: &mut dyn Iterator<Item=char>) -> Result<Option<Instruction>, ParseError> {
if let Some(c) = cs.next() {
for ins in &ins_coll.inses {
if ins.c == c {
match &ins.ins_type {
InsType::Path(ins_coll) => return match_instruction(&ins_coll, cs),
InsType::Node(ins) => {
let data = if ins.has_data() { Some(read_number(cs)?) } else { None };
return Ok(Some(ins.new_instruction(data)));
},
}
}
}
return Err(ParseError::ErrorSyntax("ERROR!!!! syntax error!".into()));
}
Ok(None)
}
fn read_number(cs: &mut dyn Iterator<Item=char>) -> Result<isize, ParseError> {
let is_positive = if let Some(c) = cs.next() {
if c == '草' { 1 } else if c == '泥' { -1 } else {
return Err(ParseError::ErrorSyntax("ERROR!!!! syntax error!".into()));
}
} else {
return Err(ParseError::ErrorSyntax("ERROR!!!! syntax error!".into()));
};
let mut num = 0_isize;
loop {
if let Some(c) = cs.next() {
if c == '马' {
break;
} else {
num <<= 1;
num += if c == '草' { 0 } else { 1 };
}
}
}
Ok(is_positive * num)
}
#[test]
fn test_read_number() {
assert_eq!(read_number(&mut "草泥马".chars()).unwrap(), 1);
assert_eq!(read_number(&mut "草泥草草草草泥泥马".chars()).unwrap(), 67);
assert_eq!(read_number(&mut "草泥草泥泥马".chars()).unwrap(), 11);
assert_eq!(read_number(&mut "草泥草草草泥草泥马".chars()).unwrap(), 69);
}