added compare operators

2 files changed, 79 insertions, 22 deletions

diff --git a/minie/e2c.c b/minie/e2c.c
index 8bd7105..e8368de 100644
--- a/minie/e2c.c
+++ b/minie/e2c.c
@@ -56,6 +56,12 @@ typedef enum {
 	S_rparen,
 	S_lbracket,
 	S_rbracket,
+	S_less,
+	S_less_or_equals,
+	S_equals,
+	S_more_or_equals,
+	S_more,
+	S_not_equals,
 	S_eof
 } Symbol;
 
@@ -90,6 +96,12 @@ char *symname[S_eof+1] = {
 	")",
 	"[",
 	"]",
+	"<",
+	"<=",
+	"=",
+	">=",
+	">",
+	"<>",
 	"eof"
 };
 
@@ -432,6 +444,26 @@ next:
 		case ']':
 			look = getChar( );
 			return S_rbracket;
+		case '<':
+			look = getChar( );
+			if( look == '=' ) {
+				look = getChar( );
+				return S_less_or_equals;
+			} else if( look == '>' ) {
+				look = getChar( );
+				return S_not_equals;
+			}
+			return S_less;
+		case '=':
+			look = getChar( );
+			return S_equals;
+		case '>':
+			look = getChar( );
+			if( look == '=' ) {
+				look = getChar( );
+				return S_more_or_equals;
+			}
+			return S_more;
 		case EOF:
 			return S_eof;
 		default:
@@ -669,6 +701,7 @@ static void variableName( void )
 }
 
 static void expression( void );
+static void simpleExpression( void );
 static void parameterList( void );
 
 static void factor( void )
@@ -723,7 +756,7 @@ static void term( void )
 	}
 }
 
-static void expression( void )
+static void simpleExpression( void )
 {
 	term( );
 	while( sym == S_plus || sym == S_minus ) {
@@ -734,6 +767,44 @@ static void expression( void )
 	}			
 }
 
+static int isRelationalOperator( Symbol sym )
+{
+	if( sym == S_less || sym == S_less_or_equals ||
+		sym == S_equals || sym == S_more ||
+		sym == S_more_or_equals || sym == S_not_equals ) {
+		return 1;
+	} else {
+		return 0;
+	}
+}	
+
+static void relationalOperator( void )
+{
+	if( sym == S_less ) {
+		emit( " < " );
+	} else if( sym == S_less_or_equals ) {
+		emit( " <= " );
+	} else if( sym == S_equals ) {
+		emit( " == " );
+	} else if( sym == S_more_or_equals ) {
+		emit( " >= " );
+	} else if( sym == S_more ) {
+		emit( " > " );
+	} else if( sym == S_not_equals ) {
+		emit( " != " );
+	}
+}
+
+static void expression( void )
+{
+	simpleExpression( );
+	if( isRelationalOperator( sym ) ) {
+		relationalOperator( );
+		sym = getSym( );
+		simpleExpression( );
+	}
+}
+
 static void assignment( void )
 {
 	Type type;
@@ -753,27 +824,12 @@ static void assignment( void )
 	emitLn( ";" );
 }
 
-static void condition( )
-{
-	identifier( );
-	/* TODO: temporary, assume we have a boolean variable */
-	if( strcmp( ident, "false" ) == 0 ) {
-		sym = getSym( );
-		emit( "0" );
-	} else if( strcmp( ident, "true" ) == 0 ) {
-		sym = getSym( );
-		emit( "1" );
-	} else {
-		Abort( "Too complex condition, expressions not implemented yet" );
-	}
-}
-
 static void statementSequence( void );
 
 static void doIf( void )
 {
 	emit( "if( " );
-	condition( );
+	expression( );
 	emitLn( ") {" );
 	Expect( S_do );
 	statementSequence( );
@@ -799,10 +855,10 @@ void static doFor( void )
 	emit( " %s = ", loopVar );
 	sym = getSym( );
 	Expect( S_assign );
-	expression( );
+	simpleExpression( );
 	emit( "; %s <= ", loopVar );
 	Expect( S_to );
-	expression( );
+	simpleExpression( );
 	/* TODO: add "by" constExpression if needed */
 	emitLn( "; %s++ ) {", loopVar ); 
 	Expect( S_do );
@@ -863,14 +919,14 @@ static void parameterList( void )
 	}
 
 	/* TODO: no VAR parameters, strictly pass-by-value */
-	expression( );
+	simpleExpression( );
 	n = 1;
 	while( sym == S_comma ) {
 		n++;
 		emit( ", " );
 		sym = getSym( );
 		/* TODO: no VAR parameters, strictly pass-by-value */
-		expression( );
+		simpleExpression( );
 	}
 
 	/* epilogue of 1-parameter function or procedure */
diff --git a/minie/test4.e b/minie/test4.e
index 24281c0..ef8ff87 100644
--- a/minie/test4.e
+++ b/minie/test4.e
@@ -16,7 +16,8 @@ begin
 	z := x;
 	c := 45;
 	x := c;
-	if false do
+	b := c < y;
+	if b do
 		if true do
 			res := 1;
 		else