From: cassowarii <cassowary@cassowary.me>
Date: Mon, 29 Jun 2026 04:55:17 +0000 (-0700)
Subject: fix minor parser bug, IR can do multi-assignment now
X-Git-Url: https://git.cassowary.me/gitweb.cgi?a=commitdiff_plain;h=79d88ca461e53405d083e36401b692b3436cb4a4;p=sarabande.git

fix minor parser bug, IR can do multi-assignment now
---

diff --git a/Makefile b/Makefile
index 9922968..a40b929 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,10 @@ build/a.out: $(OBJECTS)
 	@mkdir -p $(dir $@)
 	$(CC) $(CFLAGS) -I$(SRC) $(OBJECTS) $(LIBS) -o $@
 
+.PHONY: parsedebug
+parsedebug: CFLAGS += -DPARSEDEBUG
+parsedebug: build/a.out
+
 $(OBJ)/%.o: $(SRC)/%.c
 	@mkdir -p $(dir $@)
 	$(CC) $(CFLAGS) $(LIBS) -I$(SRC) -c $< -o $@
diff --git a/src/compile/ir.c b/src/compile/ir.c
index 80e9b8e..9fca3ed 100644
--- a/src/compile/ir.c
+++ b/src/compile/ir.c
@@ -11,7 +11,7 @@ typedef struct varmapentry {
   sbIrVariable *var;
 } varmapentry;
 
-static void compile_ast_stmtseq(hIrChunk ck, sbAst seqast);
+static void compile_ast_function(hIrChunk ck, sbAst seqast);
 static sbIrChunk *new_chunk(hIrProgram ir);
 static void chunk_deinitialize(hIrChunk ck);
 static void print_stmt(sbIrStmt *s);
@@ -37,7 +37,7 @@ void sbIrProgram_deinitialize(hIrProgram ir) {
 
 void sbIrProgram_compile_ast(hIrProgram ir, sbAst ast) {
   sbIrChunk *ck = new_chunk(ir);
-  compile_ast_stmtseq(ck, ast);
+  compile_ast_function(ck, ast);
 }
 
 void sbIrProgram_print(hIrProgram ir) {
@@ -198,9 +198,15 @@ static void put_return(hIrChunk ck) {
 }
 
 static void compile_ast_stmt(hIrChunk ck, sbAst stmtast);
+static void compile_ast_stmtseq(hIrChunk ck, sbAst seqast);
 static sbIrExpr *compile_ast_expr(hIrChunk ck, sbAst exprast);
 static sbIrVariable *compile_ast_var(hIrChunk ck, sbAst node);
 
+static void compile_ast_function(hIrChunk ck, sbAst seqast) {
+  compile_ast_stmtseq(ck, seqast);
+  put_return(ck);
+}
+
 static void compile_ast_stmtseq(hIrChunk ck, sbAst seqast) {
   usize varmapsize = ck->program->varmapping.size;
 
@@ -212,7 +218,6 @@ static void compile_ast_stmtseq(hIrChunk ck, sbAst seqast) {
     }
 
     compile_ast_stmt(ck, considering->seq.left);
-    //put_return(ck);
     considering = considering->seq.right;
   }
 
@@ -225,6 +230,7 @@ static void compile_ast_stmt(hIrChunk ck, sbAst node) {
   sbIrExpr *E1;
   sbIrLabel *L1, *L2;
   sbIrVariable *V1;
+  sbAst N1, N2;
   switch (node->type) {
     case AST_NODE_LET:
       /*
@@ -239,23 +245,62 @@ static void compile_ast_stmt(hIrChunk ck, sbAst node) {
        * TODO: I need to add support for declaring multiple
        * variables in one line.
        */
-      if (node->seq.left->type != AST_NODE_MULTIVAL) PANIC("expected multival on left side of let!");
-      const char *vname = sbSymbol_name(node->seq.left->seq.left->symb);
-      V1 = create_var(ck, vname, strlen(vname));
-      if (node->seq.right != NO_NODE) {
+      if (node->seq.right == NO_NODE) {
+        /* let ... */
+        if (node->seq.left->type != AST_NODE_MULTIVAL) PANIC("expected multival on left side of let!");
+        N1 = node->seq.left;  /* things to bind to */
+        while (N1 != NO_NODE) {
+          if (N1->seq.left->type != AST_NODE_NAME) {
+            fprintf(stderr, "Only variable names are permitted after 'let'!\n");
+            break;
+          }
+          const char *vname = sbSymbol_name(N1->seq.left->symb);
+          V1 = create_var(ck, vname, strlen(vname));
+          N1 = N1->seq.right;
+        }
+      } else {
         /* let ... = ... */
         if (node->seq.right->type != AST_NODE_MULTIVAL) PANIC("expected multival on right side of let!");
-        E1 = compile_ast_expr(ck, node->seq.right->seq.left);
-        put_assign(ck, V1, E1);
+        N1 = node->seq.left;  /* things to bind to */
+        N2 = node->seq.right; /* values to assign */
+        while (N1 != NO_NODE && N2 != NO_NODE) {
+          if (N1->seq.left->type != AST_NODE_NAME) {
+            fprintf(stderr, "Only variable names are permitted on the left side of 'let'!\n");
+            break;
+          }
+          const char *vname = sbSymbol_name(N1->seq.left->symb);
+          V1 = create_var(ck, vname, strlen(vname));
+          E1 = compile_ast_expr(ck, N2->seq.left);
+          put_assign(ck, V1, E1);
+          N1 = N1->seq.right;
+          N2 = N2->seq.right;
+        }
+        if (N1 != NO_NODE) {
+          fprintf(stderr, "too many bindings on left side of assignment!");
+        } else if (N2 != NO_NODE) {
+          fprintf(stderr, "too many values on right side of assignment!");
+        }
       }
       break;
 
     case AST_NODE_ASSIGN:
       if (node->seq.left->type != AST_NODE_MULTIVAL) PANIC("expected multival on left side of assign!");
       if (node->seq.right->type != AST_NODE_MULTIVAL) PANIC("expected multival on right side of assign!");
-      V1 = compile_ast_var(ck, node->seq.left->seq.left);
-      E1 = compile_ast_expr(ck, node->seq.right->seq.left);
-      put_assign(ck, V1, E1);
+      N1 = node->seq.left;  /* things to bind to */
+      N2 = node->seq.right; /* values to assign */
+      while (N1 != NO_NODE && N2 != NO_NODE) {
+        V1 = compile_ast_var(ck, N1->seq.left);
+        E1 = compile_ast_expr(ck, N2->seq.left);
+        put_assign(ck, V1, E1);
+        N1 = N1->seq.right;
+        N2 = N2->seq.right;
+      }
+
+      if (N1 != NO_NODE) {
+        fprintf(stderr, "too many bindings on left side of assignment!");
+      } else if (N2 != NO_NODE) {
+        fprintf(stderr, "too many values on right side of assignment!");
+      }
       break;
 
     case AST_NODE_WHILE:
diff --git a/src/parse/lexer.c b/src/parse/lexer.c
index 56369c7..17acc38 100644
--- a/src/parse/lexer.c
+++ b/src/parse/lexer.c
@@ -399,9 +399,9 @@ static void compute_next_token(hLexer lx) {
     }
 
     if (begins_brace_terminated_state(token.type)) {
-        /* only start brace-terminated state if we are actually starting a new line,
-         * or if we are after an "else" (special case for else if) */
-        if (lx->last_token_seen.type == ';' || lx->last_token_seen.type == T_rELSE) {
+        /* don't start brace-terminated state if we are directly after a '}' (otherwise it gets
+         * confused by things like repeat..until */
+        if (lx->last_token_seen.type != '}') {
             brackets_stack_push(lx, 'B');
         }
     }
diff --git a/src/parse/parser.c b/src/parse/parser.c
index 9e41f55..5d6780a 100644
--- a/src/parse/parser.c
+++ b/src/parse/parser.c
@@ -201,6 +201,11 @@ static sbLexToken next_token(hParser pr) {
 
   sbLexToken t = peek_ahead(pr, 0);
 
+#ifdef PARSEDEBUG
+  fprint_token(stdout, t);
+  printf("\n");
+#endif
+
   return t;
 }