Implement literal (expression) parsing

2 files changed, 106 insertions, 9 deletions

diff --git a/include/expr.h b/include/expr.h
index 5b0ce59..5a16f30 100644
--- a/include/expr.h
+++ b/include/expr.h
@@ -6,11 +6,11 @@
 
 struct number_e {
 	struct number value;
-	struct type type;
+	struct type *type;
 };
 
 struct array_e {
-	struct cer_array meta;
+	struct cer_array *meta;
 	struct disjunction_e *elems;
 	int elemsz, elemlen;
 };
@@ -33,7 +33,7 @@ struct literal_e {
 };
 
 struct call_e {
-	struct path path;
+	struct path *path;
 	struct disjunction_e *args;
 	int argsz, arglen;
 };
@@ -51,7 +51,7 @@ struct primary_e {
 		struct disjunction_e *grp;
 		struct literal_e lit;
 		struct call_e call;
-		struct path path;
+		struct path *path;
 	} prim;
 };
 
diff --git a/src/parse.c b/src/parse.c
index b235b24..1e9a593 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -9,6 +9,7 @@
 
 static bool parse_disjunction_e(struct lexer *lexer,
 		struct disjunction_e *out);
+static bool parse_array(struct lexer *lexer, struct type *out);
 static bool parse_type(struct lexer *lexer, struct type *out);
 
 static noreturn void
@@ -81,10 +82,103 @@ parse_grouping_e(struct lexer *lexer, struct disjunction_e *out)
 }
 
 static bool
+parse_bool_lit(struct lexer *lexer, bool *out)
+{
+	if (match(lexer, T_TRUE)) {
+		*out = true;
+	} else if (match(lexer, T_FALSE)) {
+		*out = false;
+	} else {
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+parse_string(struct lexer *lexer, char **out)
+{
+	*out = NULL;
+
+	struct token s;
+	while (lex(lexer, &s) == T_STRING) {
+		if (*out) {
+			*out = strdup(s.info.str);
+		} else {
+			size_t sz = strlen(*out) + strlen(s.info.str) + 1;
+			*out = must_realloc(*out, sz);
+		}
+	}
+	unlex(lexer, &s);
+
+	return true;
+}
+
+static bool
+parse_number_e(struct lexer *lexer, struct number_e *out)
+{
+	struct token num;
+	if (lex(lexer, &num) != T_NUMBER) {
+		return false;
+	}
+	out->value = num.info.num;
+
+	out->type = must_malloc(sizeof(struct type));
+	if (!parse_type(lexer, out->type)) {
+		error(lex_loc(lexer), "syntax error: expected type");
+	}
+
+	return true;
+}
+
+static bool
+parse_array_e(struct lexer *lexer, struct array_e *out)
+{
+	struct type type;
+	if (!parse_array(lexer, &type)) {
+		return false;
+	}
+	out->meta = must_malloc(sizeof(struct cer_array));
+	*out->meta = type.desc.array;
+
+	out->elems = must_calloc(1, sizeof(struct disjunction_e));
+	out->elemsz = 1;
+	out->elemlen = 0;
+
+	struct disjunction_e elem;
+	while (parse_disjunction_e(lexer, &elem)) {
+		if (out->elemlen >= out->elemsz) {
+			out->elemsz *= 2;
+			size_t sz = sizeof(struct disjunction_e) * out->elemsz;
+			out->elems = must_realloc(out->elems, sz);
+		}
+		out->elems[out->elemlen++] = elem;
+	}
+
+	return true;
+}
+
+static bool
 parse_literal_e(struct lexer *lexer, struct literal_e *out)
 {
-	/* TODO */
-	error(lex_loc(lexer), "unimplemented: literals");
+	if (parse_bool_lit(lexer, &out->lit.b)) {
+		out->kind = LIT_BOOL;
+		return true;
+	}
+	if (parse_string(lexer, &out->lit.str)) {
+		out->kind = LIT_STRING;
+		return true;
+	}
+	if (parse_number_e(lexer, &out->lit.num)) {
+		out->kind = LIT_NUMBER;
+		return true;
+	}
+	if (parse_array_e(lexer, &out->lit.arr)) {
+		out->kind = LIT_ARRAY;
+		return true;
+	}
+
+	return false;
 }
 
 // Invariant: Only called from parse_primary_e with path already consumed.
@@ -95,7 +189,9 @@ parse_call_e(struct lexer *lexer, struct call_e *out, struct path path)
 		return false;
 	}
 
-	out->path = path;
+	out->path = must_malloc(sizeof(struct path));
+	*out->path = path;
+
 	out->args = must_calloc(1, sizeof(struct disjunction_e));
 	out->argsz = 1;
 	out->arglen = 0;
@@ -130,9 +226,10 @@ parse_primary_e(struct lexer *lexer, struct primary_e *out)
 		out->kind = PRM_LITERAL;
 		return true;
 	}
-	if (parse_path(lexer, &out->prim.path)) {
+	out->prim.path = must_malloc(sizeof(struct path));
+	if (parse_path(lexer, out->prim.path)) {
 		out->kind = PRM_PATH;
-		if (parse_call_e(lexer, &out->prim.call, out->prim.path)) {
+		if (parse_call_e(lexer, &out->prim.call, *out->prim.path)) {
 			out->kind = PRM_CALL;
 		}
 		return true;