some dabbling with parsing ifs

3 files changed, 93 insertions, 7 deletions

diff --git a/minie/README b/minie/README
index 93e3b0e..28cae32 100644
--- a/minie/README
+++ b/minie/README
@@ -3,3 +3,7 @@ gcc -g -O0 -Wall -pedantic -std=c89 -o e2c e2c.c
 ./e2c < test2.e 
 ./e2c < test3.e 
 ./e2c < test4.e 
+
+./e2c < test4.e > test4.c && gcc -o test4 test4.c && ./test4
+
+
diff --git a/minie/e2c.c b/minie/e2c.c
index 338695d..fae65de 100644
--- a/minie/e2c.c
+++ b/minie/e2c.c
@@ -26,6 +26,9 @@ typedef enum {
 	S_begin,
 	S_end,
 	S_var,
+	S_if,
+	S_do,
+	S_else,
 	S_semicolon,
 	S_colon,
 	S_assign,
@@ -46,6 +49,9 @@ char *symname[S_eof+1] = {
 	"begin",
 	"end",
 	"var",
+	"if",
+	"do",
+	"else",
 	";",
 	":",
 	":=",
@@ -184,10 +190,17 @@ static Symbol getSym( )
 			return S_ident;
 		case 'c':
 		case 'd':
+			identifier( );
+			if( strcmp( ident, "do" ) == 0 ) {
+				return S_do;
+			}
+			return S_ident;
 		case 'e':
 			identifier( );
 			if( strcmp( ident, "end" ) == 0 ) {
 				return S_end;
+			} else if( strcmp( ident, "else" ) == 0 ) {
+				return S_else;
 			}
 			return S_ident;
 		case 'f':
@@ -195,6 +208,11 @@ static Symbol getSym( )
 		case 'h':
 		case 'j':
 		case 'i':
+			identifier( );
+			if( strcmp( ident, "if" ) == 0 ) {
+				return S_if;
+			}
+			return S_ident;
 		case 'k':
 		case 'l':
 			identifier( );
@@ -352,7 +370,14 @@ static void factor( void )
 		emit( "%d", num );		
 		sym = getSym( );
 	} else if( sym == S_ident ) {
-		emit( "%s", ident );
+		/* TODO: hacky */
+		if( strcmp( ident, "true" ) == 0 ) {
+			emit( "1" );
+		} else if( strcmp( ident, "false" ) == 0 ) {
+			emit( "0" );
+		} else {
+			emit( "%s", ident );
+		}
 		sym = getSym( );
 	} else if( sym == S_lparen ) {
 		emit( "(" );
@@ -393,11 +418,10 @@ static void expression( void )
 	}			
 }
 
-static void statement( void )
+static void assignment( void )
 {
 	char v[MAX_IDENT_LEN+1];
-	
-	if( sym == S_end ) return;
+
 	variableName( );
 	strncpy( v, ident, MAX_IDENT_LEN );
 	v[MAX_IDENT_LEN-1] = '\0';
@@ -408,15 +432,53 @@ static void statement( void )
 	emitLn( ";" );
 }
 
-static void statementBlock( void )
+static void condition( )
+{
+	identifier( );
+	sym = getSym( );
+}
+
+static void statementSequence( void );
+
+static void doIf( void )
+{
+	condition( );
+	Expect( S_do );
+	statementSequence( );
+	if( sym == S_else ) {
+		sym = getSym( );
+		statementSequence( );
+	}
+	Expect( S_end );
+}
+
+static void statement( void )
+{	
+	if( sym == S_if ) {
+		sym = getSym( );
+		doIf( );
+	/* TODO: S_else feels wrong here, just for the end ';' in an if-block */
+	} else if( sym == S_end || sym == S_else ) {
+		return;
+	} else {
+		assignment( );
+	}
+}
+
+static void statementSequence( void )
 {
-	Expect( S_begin );
 	statement( );
 	if( sym == S_end ) return;
 	while( sym == S_semicolon ) {
 		sym = getSym( );
 		statement( );
 	}
+}
+
+static void statementBlock( void )
+{
+	Expect( S_begin );
+	statementSequence( );
 	Expect( S_end );
 }
 
@@ -427,8 +489,16 @@ static void type( void )
 		/* TODO: handle build-in types in init, register them in
 		   type table */
 		if( strcmp( ident, "integer" ) == 0 ) {
-			strcpy( typeName, "int" );
+			strcpy( typeName, "signed int" );
+			sym = getSym( );
+		} else if( strcmp( ident, "bool" ) == 0 ) {
+			/* C89, no bool */
+			strcpy( typeName, "unsigned char" );
 			sym = getSym( );
+		} else if( strcmp( ident, "byte" ) == 0 ) {
+			/* C89, no bool */
+			strcpy( typeName, "unsigned char" );
+			sym = getSym( );			
 		} else {
 			Abort( "Unknown type '%s'", ident );
 		}
diff --git a/minie/test4.e b/minie/test4.e
index 303542b..22a69d8 100644
--- a/minie/test4.e
+++ b/minie/test4.e
@@ -4,9 +4,21 @@ var
 	x : integer;
 	y : integer;
 	z : integer;
+	b : bool;
+	c : byte;
+	res : integer;
 	
 begin
 	x := 7+4*(3-1/2);
 	y := -22+(-x);
 	z := x;
+	c := 45;
+	x := c;
+	if false do
+		res := 1;
+		b := true;
+	else
+		res := 2;
+		b := false;
+	end
 end