feat(bms): Full random/switch support (#109)

MikuroXina · Jan 14, 2025 · 6357d56 · 6357d56
1 parent 79f5a6a
commit 6357d56
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Showing 4 changed files with 1,129 additions and 69 deletions.
diff --git a/src/bms/lex/token.rs b/src/bms/lex/token.rs
@@ -76,7 +76,7 @@ pub enum Token<'a> {
     EndIf,
     /// `#ENDRANDOM`. Closes the random scope. See [Token::Random].
     EndRandom,
-    /// `#ENDSWITCH`. Closes the random scope. See [Token::Switch].
+    /// `#ENDSW`. Closes the random scope. See [Token::Switch].
     EndSwitch,
     /// `#EXT #XXXYY:...`. Defines the extended message. `XXX` is the track, `YY` is the channel.
     ExtendedMessage {
@@ -178,6 +178,7 @@ impl<'a> Token<'a> {
                 .ok_or_else(|| c.make_err_expected_token("command"))?;
 
             break Ok(match command.to_uppercase().as_str() {
+                // Part: Normal
                 "#PLAYER" => Self::Player(PlayerMode::from(c)?),
                 "#GENRE" => Self::Genre(c.next_line_remaining()),
                 "#TITLE" => Self::Title(c.next_line_remaining()),
@@ -227,6 +228,7 @@ impl<'a> Token<'a> {
                         Self::LnTypeRdm
                     }
                 }
+                // Part: ControlFlow/Random
                 "#RANDOM" => {
                     let rand_max = c
                         .next_token()
@@ -235,7 +237,14 @@ impl<'a> Token<'a> {
                         .map_err(|_| c.make_err_expected_token("integer"))?;
                     Self::Random(rand_max)
                 }
-                "#ENDRANDOM" => Self::EndRandom,
+                "#SETRANDOM" => {
+                    let rand_value = c
+                        .next_token()
+                        .ok_or_else(|| c.make_err_expected_token("random value"))?
+                        .parse()
+                        .map_err(|_| c.make_err_expected_token("integer"))?;
+                    Self::SetRandom(rand_value)
+                }
                 "#IF" => {
                     let rand_target = c
                         .next_token()
@@ -244,7 +253,46 @@ impl<'a> Token<'a> {
                         .map_err(|_| c.make_err_expected_token("integer"))?;
                     Self::If(rand_target)
                 }
+                "#ELSEIF" => {
+                    let rand_target = c
+                        .next_token()
+                        .ok_or_else(|| c.make_err_expected_token("random target"))?
+                        .parse()
+                        .map_err(|_| c.make_err_expected_token("integer"))?;
+                    Self::ElseIf(rand_target)
+                }
+                "#ELSE" => Self::Else,
                 "#ENDIF" => Self::EndIf,
+                "#ENDRANDOM" => Self::EndRandom,
+                // Part: ControlFlow/Switch
+                "#SWITCH" => {
+                    let switch_max = c
+                        .next_token()
+                        .ok_or_else(|| c.make_err_expected_token("switch max"))?
+                        .parse()
+                        .map_err(|_| c.make_err_expected_token("integer"))?;
+                    Self::Switch(switch_max)
+                }
+                "#SETSWITCH" => {
+                    let switch_value = c
+                        .next_token()
+                        .ok_or_else(|| c.make_err_expected_token("switch value"))?
+                        .parse()
+                        .map_err(|_| c.make_err_expected_token("integer"))?;
+                    Self::SetSwitch(switch_value)
+                }
+                "#CASE" => {
+                    let case_value = c
+                        .next_token()
+                        .ok_or_else(|| c.make_err_expected_token("switch case value"))?
+                        .parse()
+                        .map_err(|_| c.make_err_expected_token("integer"))?;
+                    Self::Case(case_value)
+                }
+                "#SKIP" => Self::Skip,
+                "#DEF" => Self::Def, // See https://hitkey.bms.ms/cmds.htm#DEF
+                "#ENDSW" => Self::EndSwitch, // See https://hitkey.bms.ms/cmds.htm#ENDSW
+                // Part: Normal 2
                 "#STAGEFILE" => Self::StageFile(
                     c.next_token()
                         .map(Path::new)
@@ -272,6 +320,7 @@ impl<'a> Token<'a> {
                     let comment = c.next_line_remaining();
                     Self::Comment(comment)
                 }
+                // Part: Command with lane and arg
                 wav if wav.starts_with("#WAV") => {
                     let id = command.trim_start_matches("#WAV");
                     let str = c.next_line_remaining();

diff --git a/src/bms/parse.rs b/src/bms/parse.rs
@@ -10,7 +10,12 @@ use std::ops::ControlFlow;
 
 use thiserror::Error;
 
-use self::{header::Header, notes::Notes, random::RandomParser, rng::Rng};
+use self::{
+    header::Header,
+    notes::Notes,
+    random::{ControlFlowRule, RandomParser},
+    rng::Rng,
+};
 use crate::lex::{
     command::ObjId,
     token::{Token, TokenStream},
@@ -22,6 +27,9 @@ pub enum ParseError {
     /// Syntax formed from the commands was invalid.
     #[error("syntax error: {0}")]
     SyntaxError(String),
+    /// Violation of control flow rule.
+    #[error("violate control flow rule: {0}")]
+    ViolateControlFlowRule(ControlFlowRule),
     /// The invalid real number for the BPM.
     #[error("not a number bpm: {0}")]
     BpmParseError(String),