From ac8e2ff4186975666527b78c98dc4959a30ec17d Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Tue, 27 Feb 2018 12:30:37 -0800
Subject: [PATCH] Implement the do-while loop.

---
 include/lexer.h |  1 +
 include/tree.h  |  1 +
 src/debug.c     |  1 +
 src/lexer.c     |  2 ++
 src/parser.c    | 40 ++++++++++++++++++++++++++++++++++++++++
 src/tree.c      |  3 ++-
 6 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/include/lexer.h b/include/lexer.h
index 2c3437f..1c667e6 100644
--- a/include/lexer.h
+++ b/include/lexer.h
@@ -61,6 +61,7 @@ enum libab_lexer_token_e {
     TOKEN_KW_IF,
     TOKEN_KW_ELSE,
     TOKEN_KW_WHILE,
+    TOKEN_KW_DO,
     TOKEN_LAST
 };
 
diff --git a/include/tree.h b/include/tree.h
index addd379..8a5f744 100644
--- a/include/tree.h
+++ b/include/tree.h
@@ -18,6 +18,7 @@ enum libab_tree_variant_e {
     VOID,
     IF,
     WHILE,
+    DOWHILE,
     CALL
 };
 
diff --git a/src/debug.c b/src/debug.c
index 8532db4..028023e 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -14,6 +14,7 @@ const char* _debug_node_name(libab_tree_variant var) {
         "void",
         "if",
         "while",
+        "dowhile",
         "call"
     };
     return names[var];
diff --git a/src/lexer.c b/src/lexer.c
index 7f65373..d479e58 100644
--- a/src/lexer.c
+++ b/src/lexer.c
@@ -14,6 +14,7 @@ libab_result libab_lexer_init(libab_lexer* lexer) {
         "if",
         "else",
         "while",
+        "do"
     };
     libab_lexer_token tokens[] = {
         TOKEN_CHAR,
@@ -22,6 +23,7 @@ libab_result libab_lexer_init(libab_lexer* lexer) {
         TOKEN_KW_IF,
         TOKEN_KW_ELSE,
         TOKEN_KW_WHILE,
+        TOKEN_KW_DO
     };
     const size_t count = sizeof(tokens)/sizeof(libab_lexer_token);
 
diff --git a/src/parser.c b/src/parser.c
index a1a1ccf..fd8d7ca 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -266,6 +266,44 @@ libab_result _parse_while(struct parser_state* state, libab_tree** store_into) {
     return result;
 }
 
+libab_result _parse_dowhile(struct parser_state* state, libab_tree** store_into) {
+    libab_result result = LIBAB_SUCCESS;
+    libab_tree* value = NULL;
+    libab_tree* condition = NULL;
+
+    if(_parser_is_type(state, TOKEN_KW_DO)) {
+        result = _parser_construct_node_vec(state->current_match, store_into);
+        if(result == LIBAB_SUCCESS) {
+            (*store_into)->variant = DOWHILE;
+            _parser_state_step(state);
+        }
+    } else {
+        result = LIBAB_UNEXPECTED;
+    }
+
+    if(result == LIBAB_SUCCESS) {
+        PARSE_CHILD(result, state, _parse_expression, value, &(*store_into)->children);
+    }
+
+    if(result == LIBAB_SUCCESS) {
+        result = _parser_consume_type(state, TOKEN_KW_WHILE);
+    }
+
+    if(result == LIBAB_SUCCESS) {
+        result = _parser_consume_char(state, '(');
+    }
+
+    if(result == LIBAB_SUCCESS) {
+        PARSE_CHILD(result, state, _parse_expression, condition, &(*store_into)->children);
+    }
+
+    if(result == LIBAB_SUCCESS) {
+        result = _parser_consume_char(state, ')');
+    }
+
+    return result;
+}
+
 libab_result _parse_call(struct parser_state* state, libab_tree** store_into) {
     libab_result result =  LIBAB_SUCCESS;
     libab_tree* temp;
@@ -326,6 +364,8 @@ libab_result _parse_atom(struct parser_state* state, libab_tree** store_into) {
         result = _parse_if(state, store_into);
     } else if(_parser_is_type(state, TOKEN_KW_WHILE)) {
         result = _parse_while(state, store_into);
+    } else if(_parser_is_type(state, TOKEN_KW_DO)) {
+        result = _parse_dowhile(state, store_into);
     } else if(_parser_is_char(state, '{')) {
         result = _parse_block(state, store_into, 1);
     } else {
diff --git a/src/tree.c b/src/tree.c
index e4bdbd1..df3c114 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -4,7 +4,8 @@
 int libab_tree_has_vector(libab_tree_variant variant) {
     return variant == BASE || variant == OP ||
             variant == UNARY_OP || variant == BLOCK ||
-            variant == IF || variant == CALL || variant == WHILE;
+            variant == IF || variant == CALL || variant == WHILE ||
+            variant == DOWHILE;
 }
 
 int libab_tree_has_string(libab_tree_variant variant) {