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Make REPL interpreter return a value

This commit is contained in:
greg 2018-03-25 00:09:51 -07:00
parent 0de504eb9e
commit eb987bb5b0
1 changed files with 35 additions and 50 deletions
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85
schala-repl/src/lib.rs
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@ -20,6 +20,7 @@ use std::fs::File;
use std::io::{Read, Write};
use std::process::exit;
use std::default::Default;
use std::fmt::Write as FmtWrite;
use rustyline::error::ReadlineError;
use rustyline::Editor;
@ -181,12 +182,13 @@ impl Repl {
println!("Terminal read error: {}", e);
},
Ok(ref input) => {
self.console.add_history_entry(input);
if self.handle_interpreter_directive(input) {
continue;
let output = match input.chars().nth(0) {
Some(ch) if ch == self.interpreter_directive_sigil => self.handle_interpreter_directive(input),
_ => Some(self.input_handler(input)),
};
if let Some(o) = output {
println!("=> {}", o);
}
let output = self.input_handler(input);
println!("=> {}", output);
}
}
}
@ -201,22 +203,16 @@ impl Repl {
interpreter_output.to_repl()
}
fn handle_interpreter_directive(&mut self, input: &str) -> bool {
match input.chars().nth(0) {
Some(ch) if ch == self.interpreter_directive_sigil => (),
_ => return false
}
fn handle_interpreter_directive(&mut self, input: &str) -> Option<String> {
let mut iter = input.chars();
iter.next();
let trimmed_sigil: &str = iter.as_str();
let commands: Vec<&str> = trimmed_sigil
let commands: Vec<&str> = iter
.as_str()
.split_whitespace()
.collect();
let cmd: &str = match commands.get(0).clone() {
None => return true,
None => return None,
Some(s) => s
};
@ -226,49 +222,46 @@ impl Repl {
exit(0)
},
"help" => {
println!("Commands:");
println!("exit | quit");
println!("lang(uage) [go|show|next|previous]");
println!("set [show|hide] [tokens|parse|symbols|eval|llvm]");
println!("options");
Some(r#"Commands:
exit | quit
lang(uage) [go|show|next|previous]
set [show|hide] [tokens|parse|symbols|eval|llvm]
options"#.to_string())
}
"lang" | "language" => {
match commands.get(1) {
Some(&"show") => {
let mut buf = String::new();
for (i, lang) in self.languages.iter().enumerate() {
if i == self.current_language_index {
println!("* {}", lang.get_language_name());
} else {
println!("{}", lang.get_language_name());
}
write!(buf, "{}{}\n", if i == self.current_language_index { "* "} else { "" }, lang.get_language_name()).unwrap();
}
Some(buf)
},
Some(&"go") => {
match commands.get(2) {
None => println!("Must specify a language name"),
None => Some(format!("Must specify a language name")),
Some(&desired_name) => {
for (i, _) in self.languages.iter().enumerate() {
let lang_name = self.languages[i].get_language_name();
if lang_name.to_lowercase() == desired_name.to_lowercase() {
self.current_language_index = i;
println!("Switching to {}", self.languages[self.current_language_index].get_language_name());
return true;
return Some(format!("Switching to {}", self.languages[self.current_language_index].get_language_name()));
}
}
println!("Language {} not found", desired_name);
Some(format!("Language {} not found", desired_name))
}
}
},
Some(&"next") => {
self.current_language_index = (self.current_language_index + 1) % self.languages.len();
println!("Switching to {}", self.languages[self.current_language_index].get_language_name());
Some(format!("Switching to {}", self.languages[self.current_language_index].get_language_name()))
}
Some(&"prev") | Some(&"previous") => {
self.current_language_index = if self.current_language_index == 0 { self.languages.len() - 1 } else { self.current_language_index - 1 };
println!("Switching to {}", self.languages[self.current_language_index].get_language_name());
Some(format!("Switching to {}", self.languages[self.current_language_index].get_language_name()))
},
Some(e) => println!("Bad `lang` argument: {}", e),
None => println!("`lang` - valid arguments `show`, `next`, `prev`|`previous`"),
Some(e) => Some(format!("Bad `lang` argument: {}", e)),
None => Some(format!("`lang` - valid arguments `show`, `next`, `prev`|`previous`")),
}
},
"set" => {
@ -276,12 +269,10 @@ impl Repl {
Some(&"show") => true,
Some(&"hide") => false,
Some(e) => {
println!("Bad `set` argument: {}", e);
return true;
return Some(format!("Bad `set` argument: {}", e));
}
None => {
println!("`set` - valid arguments `show {{option}}`, `hide {{option}}`");
return true;
return Some(format!("`set` - valid arguments `show {{option}}`, `hide {{option}}`"));
}
};
match commands.get(2) {
@ -290,15 +281,10 @@ impl Repl {
Some(&"ast") => self.options.debug.ast = show,
Some(&"symbols") => self.options.debug.symbol_table = show,
Some(&"llvm") => self.options.debug.llvm_ir = show,
Some(e) => {
println!("Bad `show`/`hide` argument: {}", e);
return true;
}
None => {
println!("`show`/`hide` requires an argument");
return true;
}
}
Some(e) => return Some(format!("Bad `show`/`hide` argument: {}", e)),
None => return Some(format!("`show`/`hide` requires an argument")),
};
None
},
"options" => {
let ref d = self.options.debug;
@ -306,12 +292,11 @@ impl Repl {
let parse_tree = if d.parse_tree { "true".green() } else { "false".red() };
let ast = if d.ast { "true".green() } else { "false".red() };
let symbol_table = if d.symbol_table { "true".green() } else { "false".red() };
println!(r#"Debug:
tokens: {}, parse: {}, ast: {}, symbols: {}"#, tokens, parse_tree, ast, symbol_table);
Some(format!(r#"Debug:
tokens: {}, parse: {}, ast: {}, symbols: {}"#, tokens, parse_tree, ast, symbol_table))
},
e => println!("Unknown command: {}", e)
e => Some(format!("Unknown command: {}", e))
}
return true;
}
}