Basic block, expression, and number parsing.

5 files changed, 111 insertions, 18 deletions

diff --git a/src/include/parser.h b/src/include/parser.h
index b39f481..59bbbb5 100644
--- a/src/include/parser.h
+++ b/src/include/parser.h
@@ -11,6 +11,8 @@ typedef struct PARSER {
    
    /* The AST being produced. */
    tree_t* tree;
+
+   /* Pointer to the part of the tree the parser is currently working on. */
 } parser_t;
 
 /* Creates a new parser. */
@@ -26,26 +28,31 @@ void parser_destroy(parser_t* parser);
 /* Step the parser forward by 1 token. */
 int parser_nxt_token(parser_t* parser);
 
-/* Check whether the current token matches the given type. */
+/* 
+   Check whether the current token matches the given type.
+   - If it doesn't, return 0 and throw error.
+*/
 int parser_match(parser_t* parser, token_type_t type);
 
-/* 
-   parse lit: converting everything from strings to value in the tree
-   parse expr: (For now) call parse lit
-   parse blk: loop over all expressions until reaching an end block.
+/* Steps the parser forward by one token, then check whether the new token matches the given type. */
+int parser_nxt_token_match(parser_t* parser, token_type_t type);
 
+/* 
+   Parse a single literal value.
+   - Only does integers for now.
 */
+tree_t* parser_parse_lit(parser_t* parser);
+
+/* Return a tree for a single semicolon-separated expression.*/
+tree_t* parser_parse_expr(parser_t* parser);
 
-/* Parse a single literal value. */
-void parser_parse_lit(parser_t* parser);
+/* Return a tree for a single curly-brace-separated expression. */
+tree_t* parser_parse_block(parser_t* parser);
 
-/* Parse a single expression. */
-void parser_parse_expr(parser_t* parser);
 
-/* Parse a single block. */
-void parser_parse_blk(parser_t* parser);
+tree_t* parser_parse(parser_t* parser);
 
-/* Parse the given tokens. */
-void parser_parse(parser_t* parser);
+/* Parse with the given parser. */
+void parser_run(parser_t* parser);
 
 #endif
diff --git a/src/include/tree.h b/src/include/tree.h
index 3dfb5be..ba1f5a5 100644
--- a/src/include/tree.h
+++ b/src/include/tree.h
@@ -5,6 +5,7 @@
 
 typedef enum TREE_TYPE {
       TREE_TYPE_BLOCK,
+      TREE_TYPE_EXPR,
       TREE_TYPE_LINT,
       TREE_TYPE_LSTR,
       TREE_TYPE_TAG,
@@ -30,6 +31,12 @@ typedef struct TREE {
          struct TREE* nxt;
       } block;
 
+      /* Expression. */
+      struct TREE_DATA_EXPR {
+         /* The contents of the expression. */
+         struct TREE* val;
+      } expr;
+
       /* Literal integer. */
       struct TREE_DATA_LINT {
          int val;
diff --git a/src/main.c b/src/main.c
index 8a60315..773134e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -46,6 +46,15 @@ int main(int argc, char* argv[]) {
    lexer_run(lexer);
    log_dbg("lexer ran");
 
+   /* Create the parser from the lexer's tokens. */
+   parser = parser_init(lexer->tokenl);
+   parser_run(parser);
+   tree_print(parser->tree, 0);
+
+   /* Clean up parser stuff. */
+   tree_destroy(parser->tree);
+   parser_destroy(parser);
+
    /* clean up lexer stuff */
    if (lexer->tokenl) { token_destroy(lexer->tokenl); } /* temp until parser eats tokens */
    lexer_destroy(lexer);
diff --git a/src/parser.c b/src/parser.c
index 0b2fa37..fb8a4aa 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -25,17 +25,79 @@ int parser_nxt_token(parser_t* parser) {
 }
 
 int parser_match(parser_t* parser, token_type_t type) {
-   return parser->token->type == type;
+   if (parser->token->type == type) {
+      return 1;
+   } else {
+      log_err("Unexpected token.");
+      return 0;
+   }
 }
 
-void parser_parse_lit(parser_t* parser) {
+int parser_nxt_token_match(parser_t* parser, token_type_t type) {
+   parser_nxt_token(parser);
+   return parser_match(parser, type);
+}
+
+tree_t* parser_parse_lit(parser_t* parser) {
+   tree_t* lint;
+
+   lint = tree_init(TREE_TYPE_LINT);
+   lint->data.lint.val = atoi(parser->token->val);
+
+   return lint;
+}
+
+tree_t* parser_parse_expr(parser_t* parser) {
+   tree_t* expr;
+
+   expr = tree_init(TREE_TYPE_EXPR);
+
+   /* For now this is the only type of expression. */
+   expr->data.expr.val = parser_parse_lit(parser);
+
+   return expr;
 }
 
-void parser_parser_expr(parser_t* parser) {
+tree_t* parser_parse_block(parser_t* parser) {
+   tree_t* block;
+
+   block = tree_init(TREE_TYPE_BLOCK);
+
+   if (parser->token->type == TOKEN_EXPR_END) {
+      if (parser_nxt_token(parser)) {
+         block->data.block.val = parser_parse_expr(parser);
+      } else {
+         block->data.block.val = NULL;
+      }
+
+      if (parser_nxt_token(parser)) {
+         block->data.block.nxt = parser_parse_block(parser);
+      } else {
+         block->data.block.nxt = NULL;
+      }
+
+      return block;
+   }
+
+   if (parser->token) {
+      block->data.block.val = parser_parse_expr(parser);
+   } else {
+      block->data.block.val = NULL;
+   }
+
+   if (parser_nxt_token(parser)) {
+      block->data.block.nxt = parser_parse_block(parser);
+   } else {
+      block->data.block.nxt = NULL;
+   }
+
+   return block;
 }
 
-void parser_parse_blk(parser_t* parser) {
+tree_t* parser_parse(parser_t* parser) {
+   return parser_parse_block(parser);
 }
 
-void parser_parse(parser_t* parser) {
+void parser_run(parser_t* parser) {
+   parser->tree = parser_parse(parser);
 }
diff --git a/src/tree.c b/src/tree.c
index 7c31956..3dfa761 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -12,6 +12,9 @@ tree_t* tree_init(int type) {
          tree->data.block.val = NULL;
          tree->data.block.nxt = NULL;
          break;
+      case TREE_TYPE_EXPR:
+         tree->data.expr.val = NULL;
+         break;
       case TREE_TYPE_LINT:
          tree->data.lint.val = 0;
          break;
@@ -70,6 +73,11 @@ void tree_print(tree_t* tree, int nest) {
          NEST(" - nxt:");
             tree_print(tree->data.block.nxt, nest + 3);
          break;
+      case TREE_TYPE_EXPR:
+         NEST("[expression]");
+         NEST(" - val:");
+            tree_print(tree->data.expr.val, nest + 3);
+            break;
       case TREE_TYPE_LINT:
          log_raw("%s[lint]: %d\n", spaces, tree->data.lint.val);
          break;