84 lines
1.7 KiB
Go
84 lines
1.7 KiB
Go
package repl
|
|
|
|
import (
|
|
"bufio"
|
|
"fmt"
|
|
"io"
|
|
"monkey/compiler"
|
|
"monkey/lexer"
|
|
"monkey/object"
|
|
"monkey/parser"
|
|
"monkey/vm"
|
|
)
|
|
|
|
const PROMPT = ">> "
|
|
|
|
func Start(in io.Reader, out io.Writer) {
|
|
scanner := bufio.NewScanner(in)
|
|
|
|
constants := []object.Object{}
|
|
globals := make([]object.Object, vm.GlobalsSize)
|
|
symbolTable := compiler.NewSymbolTable()
|
|
|
|
for {
|
|
fmt.Fprintf(out, PROMPT)
|
|
scanned := scanner.Scan()
|
|
if !scanned {
|
|
return
|
|
}
|
|
|
|
line := scanner.Text()
|
|
l := lexer.New(line)
|
|
p := parser.New(l)
|
|
|
|
program := p.ParseProgram()
|
|
if len(p.Errors()) != 0 {
|
|
printParserErrors(out, p.Errors())
|
|
continue
|
|
}
|
|
|
|
comp := compiler.NewWithState(symbolTable, constants)
|
|
err := comp.Compile(program)
|
|
if err != nil {
|
|
fmt.Fprintf(out, "Woops! Compilation failed:\n %s\n", err)
|
|
continue
|
|
}
|
|
|
|
code := comp.Bytecode()
|
|
constants = code.Constants
|
|
|
|
machine := vm.NewWithGlobalState(comp.Bytecode(), globals)
|
|
err = machine.Run()
|
|
if err != nil {
|
|
fmt.Fprintf(out, "Woops! Executing bytecode failed:\n %s\n", err)
|
|
continue
|
|
}
|
|
|
|
stackTop := machine.LastPoppedStackElem()
|
|
io.WriteString(out, stackTop.Inspect())
|
|
io.WriteString(out, "\n")
|
|
}
|
|
}
|
|
|
|
const MONKEY_FACE = ` __,__
|
|
.--. .-" "-. .--.
|
|
/ .. \/ .-. .-. \/ .. \
|
|
| | '| / Y \ |' | |
|
|
| \ \ \ 0 | 0 / / / |
|
|
\ '- ,\.-"""""""-./, -' /
|
|
''-' /_ ^ ^ _\ '-''
|
|
| \._ _./ |
|
|
\ \ '~' / /
|
|
'._ '-=-' _.'
|
|
'-----'
|
|
`
|
|
|
|
func printParserErrors(out io.Writer, errors []string) {
|
|
io.WriteString(out, MONKEY_FACE)
|
|
io.WriteString(out, "Woops! We ran into some monkey business here!\n")
|
|
io.WriteString(out, " parser errors:\n")
|
|
for _, msg := range errors {
|
|
io.WriteString(out, "\t"+msg+"\t")
|
|
}
|
|
}
|