1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162

use super::{compile::compile, Address, Link, Op, Stack, Symbol, Val};
use crate::error;
use crate::lang::{Column, Error, Line, LineNumber};
use std::sync::Arc;

/// ## Program memory

#[derive(Debug)]
pub struct Program {
    ops: Stack<Op>,
    errors: Arc<Vec<Error>>,
    indirect_errors: Arc<Vec<Error>>,
    direct_address: Address,
    line_number: LineNumber,
    link: Link,
}

impl Default for Program {
    fn default() -> Self {
        Program {
            ops: Stack::new("PROGRAM TOO LARGE"),
            errors: Arc::default(),
            indirect_errors: Arc::default(),
            direct_address: 0,
            line_number: None,
            link: Link::new(),
        }
    }
}

impl Program {
    pub fn new() -> Program {
        Program::default()
    }

    pub fn error(&mut self, error: Error) {
        Arc::make_mut(&mut self.errors).push(error.in_line_number(self.line_number));
    }

    pub fn append(&mut self, ops: &mut Stack<Op>) -> Result<(), Error> {
        self.ops.append(ops)
    }

    pub fn push(&mut self, op: Op) -> Result<(), Error> {
        self.ops.push(op)
    }

    pub fn push_for(&mut self, col: Column, ident: String) -> Result<(), Error> {
        self.link.begin_for_loop(self.ops.len(), col, ident)?;
        self.ops.push(Op::For(0))
    }

    pub fn push_next(&mut self, col: Column, ident: String) -> Result<(), Error> {
        self.ops.push(Op::Literal(Val::String(ident.clone())))?;
        self.link.next_for_loop(self.ops.len(), col, ident)?;
        self.ops.push(Op::Jump(0))
    }

    pub fn push_goto(&mut self, col: Column, line_number: LineNumber) -> Result<(), Error> {
        let sym = self.link.symbol_for_line_number(line_number)?;
        self.link.link_addr_to_symbol(self.ops.len(), col, sym);
        self.ops.push(Op::Jump(0))
    }

    pub fn push_run(&mut self, col: Column, line_number: LineNumber) -> Result<(), Error> {
        self.ops.push(Op::Clear)?;
        if line_number.is_some() {
            let sym = self.link.symbol_for_line_number(line_number)?;
            self.link.link_addr_to_symbol(self.ops.len(), col, sym);
        }
        self.ops.push(Op::Jump(0))
    }

    pub fn get(&self, addr: Address) -> Option<&Op> {
        self.ops.get(addr)
    }

    pub fn line_number_for(&self, op_addr: Address) -> LineNumber {
        self.link.line_number_for(op_addr)
    }

    pub fn clear(&mut self) {
        self.ops.clear();
        self.errors = Arc::default();
        self.indirect_errors = Arc::default();
        self.direct_address = 0;
        self.line_number = None;
        self.link.clear();
    }

    pub fn compile<'b, T: IntoIterator<Item = &'b Line>>(&mut self, lines: T) {
        let is_out_of_mem = |this: &Self| this.ops.len() > Address::max_value() as usize;
        if is_out_of_mem(self) {
            return;
        }
        let mut direct_seen = false;
        for line in lines {
            if let Some(line_number) = line.number() {
                debug_assert!(
                    self.direct_address == 0,
                    "Can't go back to indirect mode without clear()."
                );
                if let Some(self_line_number) = self.line_number {
                    debug_assert!(line_number > self_line_number, "Lines out of order.");
                }
            } else {
                self.link();
            }
            self.line_number = line.number();
            if let Some(line_number) = self.line_number {
                self.link.insert(line_number as Symbol, self.ops.len());
            } else {
                debug_assert!(!direct_seen, "Can't handle multiple direct lines.");
                direct_seen = true;
                self.ops.drain(self.direct_address..);
                Arc::make_mut(&mut self.errors).clear();
            }
            let ast = match line.ast() {
                Ok(ast) => ast,
                Err(error) => {
                    Arc::make_mut(&mut self.errors).push(error);
                    continue;
                }
            };
            compile(self, &ast);
            if self.line_number.is_none() {
                if let Err(e) = self.ops.push(Op::End) {
                    Arc::make_mut(&mut self.errors).push(e);
                }
            }
            if is_out_of_mem(self) {
                Arc::make_mut(&mut self.errors).push(error!(OutOfMemory));
                return;
            }
        }
    }

    pub fn link(&mut self) -> (Address, Arc<Vec<Error>>, Arc<Vec<Error>>) {
        match self.ops.last() {
            Some(Op::End) => {}
            _ => {
                if let Err(error) = self.ops.push(Op::End) {
                    Arc::make_mut(&mut self.errors).push(error);
                }
            }
        };
        let mut link_errors = self.link.link(&mut self.ops);
        if self.errors.is_empty() {
            Arc::make_mut(&mut self.errors).append(&mut link_errors);
        }
        if self.direct_address == 0 {
            self.indirect_errors = std::mem::take(&mut self.errors);
            self.direct_address = self.ops.len();
            self.link.set_start_of_direct(self.ops.len());
        }
        (
            self.direct_address,
            Arc::clone(&self.indirect_errors),
            Arc::clone(&self.errors),
        )
    }
}