commit 18bdcb0101c47da2fb1a046c30e38eba48dbf5b6
parent e065976bc7633261152b211d79f6f94d232e33f5
Author: Ashymad <szymon.mikulicz@posteo.net>
Date: Sat, 9 Mar 2024 10:49:10 +0100
Implement ternary
Diffstat:
2 files changed, 71 insertions(+), 41 deletions(-)
diff --git a/zlox/src/compiler.zig b/zlox/src/compiler.zig
@@ -9,6 +9,7 @@ pub const CompilerError = scanner.ScannerError || chunk.ChunkError || value.Pars
const Precedence = enum {
NONE,
ASSIGNMENT, // =
+ TERNARY, // ? :
OR, // or
AND, // and
EQUALITY, // == !=
@@ -39,54 +40,66 @@ pub const Compiler = struct {
const ParseFn = *const fn (*@This()) void;
- const ParseRule = struct { prefix: ?ParseFn, infix: ?ParseFn, precedence: Precedence };
+ const ParseRule = struct {
+ prefix: ?ParseFn,
+ infix: ?ParseFn,
+ precedence: Precedence,
+ pub fn init(prefix: ?ParseFn, infix: ?ParseFn, precedence: Precedence) @This() {
+ return @This(){ .prefix = prefix, .infix = infix, .precedence = precedence };
+ }
+ };
const rules = init: {
var new: [@typeInfo(scanner.TokenType).Enum.fields.len]ParseRule = undefined;
for (&new, 0..) |*v, i| {
- const tok: scanner.TokenType = @enumFromInt(i);
const T = scanner.TokenType;
+ const S = @This();
+ const R = ParseRule.init;
+ const P = Precedence;
+ const tok: T = @enumFromInt(i);
v.* = switch (tok) {
// zig fmt: off
- T.LEFT_PAREN => ParseRule{ .prefix = @This().grouping, .infix = null, .precedence = Precedence.NONE },
- T.RIGHT_PAREN => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.LEFT_BRACE => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.RIGHT_BRACE => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.COMMA => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.DOT => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.MINUS => ParseRule{ .prefix = @This().unary, .infix = @This().binary, .precedence = Precedence.TERM },
- T.PLUS => ParseRule{ .prefix = null, .infix = @This().binary, .precedence = Precedence.TERM },
- T.SEMICOLON => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.SLASH => ParseRule{ .prefix = null, .infix = @This().binary, .precedence = Precedence.FACTOR },
- T.STAR => ParseRule{ .prefix = null, .infix = @This().binary, .precedence = Precedence.FACTOR },
- T.BANG => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.BANG_EQUAL => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.EQUAL => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.EQUAL_EQUAL => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.GREATER => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.GREATER_EQUAL => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.LESS => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.LESS_EQUAL => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.IDENTIFIER => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.STRING => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.NUMBER => ParseRule{ .prefix = @This().number, .infix = null, .precedence = Precedence.NONE },
- T.AND => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.CLASS => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.ELSE => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.FALSE => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.FOR => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.FUN => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.IF => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.NIL => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.OR => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.PRINT => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.RETURN => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.SUPER => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.THIS => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.TRUE => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.VAR => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.WHILE => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
- T.EOF => ParseRule{ .prefix = null, .infix = null, .precedence = Precedence.NONE },
+ T.LEFT_PAREN => R(S.grouping, null, P.NONE ),
+ T.RIGHT_PAREN => R(null, null, P.NONE ),
+ T.LEFT_BRACE => R(null, null, P.NONE ),
+ T.RIGHT_BRACE => R(null, null, P.NONE ),
+ T.COMMA => R(null, null, P.NONE ),
+ T.DOT => R(null, null, P.NONE ),
+ T.MINUS => R(S.unary, S.binary, P.TERM ),
+ T.PLUS => R(null, S.binary, P.TERM ),
+ T.COLON => R(null, null, P.NONE ),
+ T.SEMICOLON => R(null, null, P.NONE ),
+ T.SLASH => R(null, S.binary, P.FACTOR ),
+ T.STAR => R(null, S.binary, P.FACTOR ),
+ T.QUESTION => R(null, S.ternary, P.TERNARY ),
+ T.BANG => R(null, null, P.NONE ),
+ T.BANG_EQUAL => R(null, null, P.NONE ),
+ T.EQUAL => R(null, null, P.NONE ),
+ T.EQUAL_EQUAL => R(null, null, P.NONE ),
+ T.GREATER => R(null, null, P.NONE ),
+ T.GREATER_EQUAL => R(null, null, P.NONE ),
+ T.LESS => R(null, null, P.NONE ),
+ T.LESS_EQUAL => R(null, null, P.NONE ),
+ T.IDENTIFIER => R(null, null, P.NONE ),
+ T.STRING => R(null, null, P.NONE ),
+ T.NUMBER => R(S.number, null, P.NONE ),
+ T.AND => R(null, null, P.NONE ),
+ T.CLASS => R(null, null, P.NONE ),
+ T.ELSE => R(null, null, P.NONE ),
+ T.FALSE => R(null, null, P.NONE ),
+ T.FOR => R(null, null, P.NONE ),
+ T.FUN => R(null, null, P.NONE ),
+ T.IF => R(null, null, P.NONE ),
+ T.NIL => R(null, null, P.NONE ),
+ T.OR => R(null, null, P.NONE ),
+ T.PRINT => R(null, null, P.NONE ),
+ T.RETURN => R(null, null, P.NONE ),
+ T.SUPER => R(null, null, P.NONE ),
+ T.THIS => R(null, null, P.NONE ),
+ T.TRUE => R(null, null, P.NONE ),
+ T.VAR => R(null, null, P.NONE ),
+ T.WHILE => R(null, null, P.NONE ),
+ T.EOF => R(null, null, P.NONE ),
// zig fmt: on
};
}
@@ -257,6 +270,19 @@ pub const Compiler = struct {
}
}
+ fn ternary(self: *@This()) void {
+ const operatorType = self.previous.type catch unreachable;
+ self.parsePrecedence(getRule(operatorType).precedence.inc());
+
+ // emit bytecode
+
+ self.consume(scanner.TokenType.COLON, "Expected ':' in ternary expression.");
+
+ self.parsePrecedence(getRule(operatorType).precedence.inc());
+
+ // emit bytecode
+ }
+
pub fn compile(source: []const u8, ch: *chunk.Chunk) CompilerError!void {
var self = @This(){ .scanner = try scanner.Scanner.init(source), .current = scanner.Token.Empty, .previous = scanner.Token.Empty, .panicMode = false, .hadError = false, .lastError = scanner.ScannerError.EmptyToken, .compilingChunk = ch };
self.advance();
diff --git a/zlox/src/scanner.zig b/zlox/src/scanner.zig
@@ -10,9 +10,11 @@ pub const TokenType = enum {
DOT,
MINUS,
PLUS,
+ COLON,
SEMICOLON,
SLASH,
STAR,
+ QUESTION,
// One or two character tokens.
BANG,
BANG_EQUAL,
@@ -103,6 +105,7 @@ pub const Scanner = struct {
')' => return self.makeToken(TokenType.RIGHT_PAREN),
'{' => return self.makeToken(TokenType.LEFT_BRACE),
'}' => return self.makeToken(TokenType.RIGHT_BRACE),
+ ':' => return self.makeToken(TokenType.COLON),
';' => return self.makeToken(TokenType.SEMICOLON),
',' => return self.makeToken(TokenType.COMMA),
'.' => return self.makeToken(TokenType.DOT),
@@ -110,6 +113,7 @@ pub const Scanner = struct {
'+' => return self.makeToken(TokenType.PLUS),
'/' => return self.makeToken(TokenType.SLASH),
'*' => return self.makeToken(TokenType.STAR),
+ '?' => return self.makeToken(TokenType.QUESTION),
'!' => return self.makeToken(if (self.match('=')) TokenType.BANG_EQUAL else TokenType.BANG),
'=' => return self.makeToken(if (self.match('=')) TokenType.EQUAL_EQUAL else TokenType.EQUAL),
'<' => return self.makeToken(if (self.match('=')) TokenType.LESS_EQUAL else TokenType.LESS),
