added expressions

2 files changed, 67 insertions, 13 deletions

diff --git a/minie/e2c.c b/minie/e2c.c
index c155164..8c33b0d 100644
--- a/minie/e2c.c
+++ b/minie/e2c.c
@@ -29,6 +29,12 @@ typedef enum {
 	S_semicolon,
 	S_colon,
 	S_assign,
+	S_plus,
+	S_minus,
+	S_star,
+	S_slash,
+	S_lparen,
+	S_rparen,
 	S_eof
 } Symbol;
 
@@ -43,6 +49,12 @@ char *symname[S_eof+1] = {
 	";",
 	":",
 	":=",
+	"+",
+	"-",
+	"*",
+	"/",
+	"(",
+	")",
 	"eof"
 };
 
@@ -249,10 +261,28 @@ static Symbol getSym( )
 		case ';':
 			look = getChar( );
 			return S_semicolon;
+		case '+':
+			look = getChar( );
+			return S_plus;
+		case '-':
+			look = getChar( );
+			return S_minus;
+		case '*':
+			look = getChar( );
+			return S_star;
+		case '/':
+			look = getChar( );
+			return S_slash;
+		case '(':
+			look = getChar( );
+			return S_lparen;
+		case ')':
+			look = getChar( );
+			return S_rparen;
 		case EOF:
 			return S_eof;
 		default:
-			Abort( "Illegal character" );
+			Abort( "Illegal character '%c'", (char)look );
 	}
 	return S_char;
 }
@@ -262,13 +292,7 @@ static void Expect( Symbol expect )
 	if( sym == expect ) {
 		sym = getSym( );
 	} else {
-		char s[MAX_ERRMSG_LEN+1];
-		s[0] = '\0';
-		strncat( s, "Expected symbol '", MAX_ERRMSG_LEN );
-		strncat( s, symname[expect], MAX_ERRMSG_LEN );
-		strncat( s, "'", MAX_ERRMSG_LEN );
-		s[MAX_ERRMSG_LEN-1] = '\0';
-		Abort( s );
+		Abort( "Expected symbol '%s'", symname[expect] );
 	}
 }
 
@@ -320,19 +344,49 @@ static void variableName( void )
 	}
 }
 
-static void expression( void )
+static void expression( void );
+
+static void factor( void )
 {
 	if( sym == S_number ) {
-		emit( "%d;", num );		
+		emit( "%d", num );		
 		sym = getSym( );
 	} else if( sym == S_ident ) {
-		emit( "%s;", ident );
+		emit( "%s", ident );
 		sym = getSym( );
+	} else if( sym == S_lparen ) {
+		emit( "(" );
+		sym = getSym( );
+		expression( );
+		Expect( S_rparen );
+		emit( ")" );
 	} else {
 		Abort( "Expected expression" );
 	}
 }
 
+static void term( void )
+{
+	factor( );
+	while( sym == S_star || sym == S_slash ) {
+		if( sym == S_star ) emit( "*" );
+		if( sym == S_slash ) emit( "/" );
+		sym = getSym( );
+		factor( );
+	}
+}
+
+static void expression( void )
+{
+	term( );
+	while( sym == S_plus || sym == S_minus ) {
+		if( sym == S_plus ) emit( "+" );
+		if( sym == S_minus ) emit( "-" );
+		sym = getSym( );
+		term( );
+	}			
+}
+
 static void statement( void )
 {
 	char v[MAX_IDENT_LEN+1];
@@ -345,7 +399,7 @@ static void statement( void )
 	Expect( S_assign );
 	emit( "%s = ", v );
 	expression( );
-	emitLn( "" );
+	emitLn( ";" );
 }
 
 static void statementBlock( void )
diff --git a/minie/test4.e b/minie/test4.e
index 18ba33b..23c6278 100644
--- a/minie/test4.e
+++ b/minie/test4.e
@@ -6,7 +6,7 @@ var
 	z : integer;
 	
 begin
-	x := 7;
+	x := 7+4*(3-1/2);
 	y := 22;
 	z := x;
 end