cond implemented

special form, not as a macro

debug.lsp

@@ -1,5 +1,14 @@
-(defun a (aa) (print aa))
+(define a 20)
-(a 1 2)
+(cond 
+	((> a 30) (print "a > 30"))
+	((> a 20) (print "a > 20"))
+	(1 (print "a je" a)))
+
+(define a 25)
+(cond 
+	((> a 30) (print "a > 30"))
+	((> a 20) (print "a > 20"))
+	(1 (print "a je" a)))
 
 ;; (define csv_date (str-to-date "01/01/2021" "%m/%d/%Y"))
 ;; (date-to-str 3141583200 "%m/%d/%Y")

ml.cpp

@@ -165,7 +165,6 @@ std::vector<std::string> MlValue::get_used_atoms() {
 	}
 }
 
-// Is this a builtin function?
 bool MlValue::is_builtin() const {
 	return type == BUILTIN;
 }
@@ -178,6 +177,10 @@ bool MlValue::is_string() const {
 	return type == STRING;
 }
 
+bool MlValue::is_list() const {
+	return type == LIST;
+}
+
 // Get the "truthy" boolean value of this value.
 bool MlValue::as_bool() const {
 	return type != NIL && *this != MlValue(0l);        // TODO remove 0 as false
@@ -376,13 +379,13 @@ MlValue MlValue::operator+(const MlValue &other) const {
 			// before continuing with the addition.
 			if (other.type == FLOAT)
 				return MlValue(cast_to_float() + other.stack_data.f);
-				// Otherwise, do integer addition.
+			// Otherwise, do integer addition.
 			else return MlValue(stack_data.i + other.stack_data.i);
 		case STRING:
 			// If the other value is also a string, do the concat
 			if (other.type == STRING)
 				return MlValue::string(str + other.str);
-				// We throw an error if we try to concat anything of non-string type
+			// We throw an error if we try to concat anything of non-string type
 			else throw MlError(*this, MlEnvironment(), INVALID_BIN_OP);
 		case LIST:
 			// If the other value is also a list, do the concat
@@ -921,6 +924,28 @@ MlValue if_then_else(std::vector<MlValue> args, MlEnvironment &env) {
 	return MlValue(0l);
 }
 
+// cond (SPECIAL FORM), in lisp it's macro, but we don't have support for macros yet
+MlValue cond(std::vector<MlValue> args, MlEnvironment &env) {
+	if (args.size() < 2)
+		throw MlError(MlValue("cond", cond), env, TOO_FEW_ARGS);
+
+	MlValue acc;
+	for (auto &arg : args) {
+		if (!arg.is_list())
+			throw MlError(MlValue("cond", cond), env, INVALID_ARGUMENT);
+
+		std::vector<MlValue> list = arg.as_list();
+		if (list[0].eval(env).as_bool()) {
+			for (size_t i = 1; i < list.size(); i++)
+				acc = list[i].eval(env);
+
+			return acc;
+		}
+	}
+
+	return MlValue::nil();
+}
+
 // Define a variable with a value (SPECIAL FORM)
 MlValue define(std::vector<MlValue> args, MlEnvironment &env) {
 	if (args.size() != 2)
@@ -1934,8 +1959,10 @@ bool MlEnvironment::has(const std::string &name) const {
 // Get the value associated with this name in this scope
 MlValue MlEnvironment::get(const std::string &name) const {
 	// Special forms
-	if (name == "if") return MlValue("if", builtin::if_then_else);
 	if (name == "define") return MlValue("define", builtin::define);
+	if (name == "set!") return MlValue("set!", builtin::setx);
+	if (name == "if") return MlValue("if", builtin::if_then_else);
+	if (name == "cond") return MlValue("if", builtin::cond);
 	if (name == "do") return MlValue("do", builtin::do_block);
 	if (name == "for") return MlValue("for", builtin::for_loop);
 	if (name == "while") return MlValue("while", builtin::while_loop);
@@ -1945,7 +1972,6 @@ MlValue MlEnvironment::get(const std::string &name) const {
 	if (name == "lambda") return MlValue("lambda", builtin::lambda);
 	if (name == "and") return MlValue("and", builtin::do_and);
 	if (name == "or") return MlValue("or", builtin::do_or);
-	if (name == "set!") return MlValue("set!", builtin::setx);
 
 	// Comparison operations
 	if (name == "=") return MlValue("=", builtin::eq);

ml.h

@@ -145,6 +145,8 @@ public:
 
     bool is_string() const;
 
+    bool is_list() const;
+
     // Get the boolean value of this value.
     bool as_bool() const;
 

utils/Lisp.tmLanguage

@@ -136,7 +136,7 @@
 		</dict>
 		<dict>
 			<key>match</key>
-			<string>(?<=\()(?i:\*|\*\*|\*\*\*|\+|\+\+|\+\+\+|\-|/|//|///|/=|1\+|1\-|<|<=|=|>|>=|if|do|for|while|scope|quote|defun|and|or|set!|eval|type|parse|list|insert|index|remove|len|push|pop|head|tail|first|last|range|map|filter|reduce|exit|quit|print|input|random|include|read-file|read-file-lines|write-file|read-url|system-cmd|ls-dir|is-file?|is-dir?|parse-csv|parse-json|get-universal-time|date-to-str|str-to-date|date-add|debug|sprintf|display|string-replace|string-regex?|string-split|string-pad|string-rltrim|string-case|string-len|string-substr|string-find|benchmark|thread-create|thread-under-lock|thread-sleep|threads-join|try|throw|usql|first|second|third|fourth|fifth|sixth|seventh|eight|nth|print|get-universal-time|not|is-pos?|is-neg?|neg|dec|inc|string-ltrim|string-rtrim|string-trim|string-rpad|string-lpad|string-upcase|string-downcase|string-join|itok|ktoi|sleep|get-env|member|make-list-of|make-list|empty-list?|uniq|flatten|quick-sort-by|quick-sort|quick-sort-reverse|start-of-day|end-of-day|start-of-month|start-of-next-month|end-of-next-month|end-of-month|start-of-prev-month|end-of-prev-month|start-of-year|end-of-year|make-csv)(?=\s+)</string>
+			<string>(?<=\()(?i:\*|\*\*|\*\*\*|\+|\+\+|\+\+\+|\-|/|//|///|/=|1\+|1\-|<|<=|=|>|>=|if|cond|do|for|while|scope|quote|defun|and|or|set!|eval|type|parse|list|insert|index|remove|len|push|pop|head|tail|first|last|range|map|filter|reduce|exit|quit|print|input|random|include|read-file|read-file-lines|write-file|read-url|system-cmd|ls-dir|is-file?|is-dir?|parse-csv|parse-json|get-universal-time|date-to-str|str-to-date|date-add|debug|sprintf|display|string-replace|string-regex?|string-split|string-pad|string-rltrim|string-case|string-len|string-substr|string-find|benchmark|thread-create|thread-under-lock|thread-sleep|threads-join|try|throw|usql|first|second|third|fourth|fifth|sixth|seventh|eight|nth|print|get-universal-time|not|is-pos?|is-neg?|neg|dec|inc|string-ltrim|string-rtrim|string-trim|string-rpad|string-lpad|string-upcase|string-downcase|string-join|itok|ktoi|sleep|get-env|member|make-list-of|make-list|empty-list?|uniq|flatten|quick-sort-by|quick-sort|quick-sort-reverse|start-of-day|end-of-day|start-of-month|start-of-next-month|end-of-next-month|end-of-month|start-of-prev-month|end-of-prev-month|start-of-year|end-of-year|make-csv)(?=\s+)</string>
 			<key>name</key>
 			<string>keyword.control.lisp</string>
 		</dict>