From 51eef06ddfb82bedab4f5d70932132e28ba4249a Mon Sep 17 00:00:00 2001
From: sanine <sanine.not@pm.me>
Date: Fri, 19 May 2023 21:57:06 -0500
Subject: initial pass at grammar

---
 src/parser/grammar.jison | 111 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 src/parser/grammar.jison

(limited to 'src/parser/grammar.jison')

diff --git a/src/parser/grammar.jison b/src/parser/grammar.jison
new file mode 100644
index 0000000..4a17d2b
--- /dev/null
+++ b/src/parser/grammar.jison
@@ -0,0 +1,111 @@
+%lex
+
+%%
+
+";"              { this.pushState('comment'); return "COMMENT"; }
+<comment>"\n"    { this.popState(); return "NEWLINE";           }
+<comment>.       { /* ignore anything else inside a comment */  }
+
+"\n"             { return "NEWLINE";       }
+\s+              { /* ignore whitespace */ }
+
+"MOV"            { return "MOV"; }
+"ADD"            { return "ADD"; }
+"SUB"            { return "SUB"; }
+"CMP"            { return "CMP"; }
+"SLT"            { return "SLT"; }
+"JMP"            { return "JMP"; }
+"JMZ"            { return "JMZ"; }
+"JMN"            { return "JMN"; }
+"DJN"            { return "DJN"; }
+"SPL"            { return "SPL"; }
+"DAT"            { return "DAT"; }
+
+"EQU"            { return "EQU"; }
+"END"            { return "END"; }
+":"              { return ":"; }
+
+"#"              { return "#"; }
+"@"              { return "@"; }
+"<"              { return "<"; }
+"$"              { return "$"; }
+
+"("              { return "("; }
+")"              { return ")"; }
+"+"              { return "+"; }
+"-"              { return "-"; }
+"*"              { return "*"; }
+"/"              { return "/"; }
+[0-9]+           { return "NUMBER"; }
+[A-Z][A-Z0-9_]+  { return "LABEL";  }
+
+/lex
+
+%%
+
+
+program
+	: lines { return $lines; }
+	;
+
+
+
+lines
+	: lines line { $lines.push($line); $$ = $lines; }
+	| line { $$ = [ $line ]; }
+	;
+
+line
+	: op NEWLINE { $$ = $op; }
+	| op EOF     { $$ = $op; }
+	;
+
+
+op
+	: opcode address address
+	{ $$ = { opcode: $opcode, a: $address1, b: $address2 }; }
+	;
+
+
+opcode
+	: MOV { $$ = $1; }
+	| ADD { $$ = $1; }
+	| SUB { $$ = $1; }
+	| CMP { $$ = $1; }
+	| SLT { $$ = $1; }
+	| JMP { $$ = $1; }
+	| JMZ { $$ = $1; }
+	| JMN { $$ = $1; }
+	| DJN { $$ = $1; }
+	| SPL { $$ = $1; }
+	| DAT { $$ = $1; }
+	;
+
+
+address:
+	: address_mode e { $$ = { mode: $1, value: $2 }; }
+	| e              { $$ = { mode: 'direct', value: $1 }; }
+	;
+
+
+address_mode
+	: "#" { $$ = 'immediate';    }
+	| "@" { $$ = 'indirect';     } 
+	| "<" { $$ = 'predecrement'; }
+	| "$" { $$ = 'direct';       }
+	;
+
+e
+	: NUMBER { $$ = Math.floor(Number(yytext)); }
+	| LABEL  {
+		$$ = yy.getLabel(yytext);
+		if ($$ === null) {
+			YYABORT;
+		}
+	}
+	| e '+' e   { $$ = Math.floor($e1 + $e2); }
+	| e '-' e   { $$ = Math.floor($e1 - $e2); }
+	| e '*' e   { $$ = Math.floor($e1 * $e2); }
+	| e '/' e   { $$ = Math.floor($e1 / $e2); }
+	| '(' e ')' { $$ = Math.floor($e); }
+	;
-- 
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