diff --git a/compiler.c b/compiler.c index a2e0b3f..8968925 100644 --- a/compiler.c +++ b/compiler.c @@ -49,6 +49,7 @@ typedef struct { typedef enum { PREC_NONE, PREC_ASSIGNMENT, /* = */ + PREC_TERNARY, PREC_OR, /* or */ PREC_AND, /* and */ PREC_BITOR, /* | */ @@ -178,6 +179,7 @@ static void expression(); static void statement(); static void declaration(); static void or_(int canAssign); +static void ternary(int canAssign); static void and_(int canAssign); static void classDeclaration(); static void declareVariable(); @@ -1772,7 +1774,7 @@ ParseRule rules[] = { RULE(TOKEN_FALSE, literal, NULL, PREC_NONE), RULE(TOKEN_FOR, NULL, NULL, PREC_NONE), RULE(TOKEN_DEF, NULL, NULL, PREC_NONE), - RULE(TOKEN_IF, NULL, NULL, PREC_NONE), + RULE(TOKEN_IF, NULL, ternary,PREC_TERNARY), RULE(TOKEN_IN, NULL, in_, PREC_COMPARISON), RULE(TOKEN_LET, NULL, NULL, PREC_NONE), RULE(TOKEN_NONE, literal, NULL, PREC_NONE), @@ -1809,7 +1811,38 @@ ParseRule rules[] = { RULE(TOKEN_EOF, NULL, NULL, PREC_NONE), }; +static void actualTernary(size_t count, KrkScanner oldScanner, Parser oldParser) { + currentChunk()->count = count; + + parsePrecedence(PREC_OR); + + int thenJump = emitJump(OP_JUMP_IF_TRUE); + emitByte(OP_POP); /* Pop the condition */ + consume(TOKEN_ELSE, "Expected 'else' after ternary condition"); + + parsePrecedence(PREC_OR); + + KrkScanner outScanner = krk_tellScanner(); + Parser outParser = parser; + + int elseJump = emitJump(OP_JUMP); + patchJump(thenJump); + emitByte(OP_POP); + + krk_rewindScanner(oldScanner); + parser = oldParser; + parsePrecedence(PREC_OR); + patchJump(elseJump); + + krk_rewindScanner(outScanner); + parser = outParser; +} + static void parsePrecedence(Precedence precedence) { + size_t count = currentChunk()->count; + KrkScanner oldScanner = krk_tellScanner(); + Parser oldParser = parser; + advance(); ParseFn prefixRule = getRule(parser.previous.type)->prefix; if (prefixRule == NULL) { @@ -1821,7 +1854,11 @@ static void parsePrecedence(Precedence precedence) { while (precedence <= getRule(parser.current.type)->precedence) { advance(); ParseFn infixRule = getRule(parser.previous.type)->infix; - infixRule(canAssign); + if (infixRule == ternary) { + actualTernary(count, oldScanner, oldParser); + } else { + infixRule(canAssign); + } } if (canAssign && matchAssignment()) { @@ -1988,6 +2025,10 @@ static void and_(int canAssign) { patchJump(endJump); } +static void ternary(int canAssign) { + error("This function should not run."); +} + static void or_(int canAssign) { int endJump = emitJump(OP_JUMP_IF_TRUE); emitByte(OP_POP); diff --git a/test/testTernary.krk b/test/testTernary.krk new file mode 100644 index 0000000..8023c5a --- /dev/null +++ b/test/testTernary.krk @@ -0,0 +1,19 @@ +def foo(): + print("Called foo") + return 42 + +def bar(): + print("Called bar") + return "a string" + +let x = foo() if True else bar() +print(x) + +let y = foo() if False else bar() +print(y) + +let z = foo() if y == "a string" else bar() +print(z) + +let l = (lambda x: x * 72) if x == 42 else (lambda y: y - 48) +print(l(x)) diff --git a/test/testTernary.krk.expect b/test/testTernary.krk.expect new file mode 100644 index 0000000..13d39c8 --- /dev/null +++ b/test/testTernary.krk.expect @@ -0,0 +1,7 @@ +Called foo +42 +Called bar +a string +Called foo +42 +3024