jmug/interpreter-in-go
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Add error message to the REPL

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Signed-off-by: jmug <u.g.a.mariano@gmail.com>
This commit is contained in:
Mariano Uvalle 2025-01-06 16:36:24 -08:00
parent 44f936affb
commit acc6707740
1 changed files with 30 additions and 3 deletions
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33
pkg/repl/repl.go
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@ -6,7 +6,7 @@ import (
"io"
"code.jmug.me/jmug/interpreter-in-go/pkg/lexer"
"code.jmug.me/jmug/interpreter-in-go/pkg/token"
"code.jmug.me/jmug/interpreter-in-go/pkg/parser"
)
const PROMPT = ">> "
@ -19,8 +19,35 @@ func Start(in io.Reader, out io.Writer) {
return
}
l := lexer.New(scanner.Text())
for tok := l.NextToken(); tok.Type != token.EOF; tok = l.NextToken() {
fmt.Fprintf(out, "%+v\n", tok)
p := parser.New(l)
program := p.ParseProgram()
if len(p.Errors()) != 0 {
printParserErrors(out, p.Errors())
continue
}
io.WriteString(out, program.String())
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+"\n")
}
}