basic ast renderer

source/ast/ast.hon

@@ -1,7 +1,15 @@
+#! GRAMMAR:
+#! * type ..... -> identifier
+#! * assignment -> :: | :=
+#! * literal .. -> int | float | string
+#! * expr ..... -> identifier | literal
+#! * decl ..... -> identifier [type] assignment expr
+#! * stmt ..... -> decl
+
+import "@std/debug"
 import "@source/lexer"
 
-hide TokenId :: alias lexer.TokenId
-hide Token :: alias lexer.Token
+hide(file) TokenId :: alias lexer.TokenId
 
 NodeId :: distinct u32
 ExtraId :: distinct u32
@@ -44,27 +52,18 @@ NodeKind :: enum {
     # * data0: ExtraId
     #   + extra[data0]: NodeId - type identifier node
     #   + extra[data0 + 1]: NodeId - initializer expression
-    # * data1: TokenId of either `::` or `=` indicating mutability
+    # * data1: TokenId of either `::` or `:=` indicating mutability
     stmt_decl
 
     invalid
 }
 
-# todo: render ast nodes as source code
-
-render proc(node @Node, tokens []Token) void { }
-
-render_literal proc(node @Node, tokens []Token, program []u8) []u8 ! lexer.ScanError {
-    tok :: tokens[node.main_token]
-    match node.kind {
-        .literal_int, .literal_float: {
-            result :: try lexer.scan_number(tok.start, program)
-            return program[tok.start..result.end]
-        }
-        .literal_string: {
-            result :: try lexer.scan_string(tok.start, program)
-            return program[tok.start..result.end]
-        }
-        else: unreachable
-    }
+node_id proc(idx uint) NodeId {
+    debug.assert(u64(idx) < u64(NO_ID_NODE))
+    return NodeId(idx)
+}
+
+extra_id proc(idx uint) ExtraId {
+    debug.assert(u64(idx) < u64(NO_ID_EXTRA))
+    return ExtraId(idx)
 }

source/ast/renderer/renderer.hon

@@ -0,0 +1,119 @@
+import "@std"
+import "@std/mem"
+import "@std/arraylist"
+
+import "@source/lexer"
+import "@source/parser"
+import "@source/ast"
+
+hide(file) TokenId :: alias lexer.TokenId
+hide(file) Token :: alias lexer.Token
+hide(file) Node :: alias ast.Node
+hide(file) NodeId :: alias ast.NodeId
+hide(file) ParseState :: alias parser.State
+
+Renderer :: struct { tokens std.ArrayList(Token) }
+
+init proc(allocator mem.Allocator) Renderer {
+    return Renderer{ tokens = arraylist.init(allocator) }
+}
+
+deinit proc(renderer @mut Renderer) void {
+    arraylist.deinit(&renderer.tokens)
+}
+
+render proc(
+    renderer @mut Renderer,
+    node_id NodeId,
+    parse_state @ParseState,
+    tokens []Token,
+) void ! mem.AllocError {
+    node :: parse_state.nodes.items[usize(node_id)]
+    match node.kind {
+        .stmt_decl: try render_stmt_decl(renderer, node_id, parse_state, tokens)
+        else: unreachable
+    }
+}
+
+render_stmt_decl proc(
+    renderer @mut Renderer,
+    node_id NodeId,
+    parse_state @ParseState,
+    tokens []Token,
+) void ! mem.AllocError {
+    node :: parse_state.nodes.items[usize(node_id)]
+    tok_ident :: tokens[usize(node.main_token)]
+    try arraylist.append(&renderer.tokens, tok_ident)
+
+    node_id_type :: ast.node_id(parse_state.extra.items[usize(node.data0.extra_id)])
+    try render_type(renderer, node_id_type, parse_state, tokens)
+
+    tok_assign :: tokens[usize(node.data1.token_id)]
+    try arraylist.append(&renderer.tokens, tok_assign)
+
+    node_id_expr :: ast.node_id(parse_state.extra.items[usize(node.data0.extra_id + 1)])
+    last_expr_token :: try render_expr(renderer, node_id_expr, parse_state, tokens)
+
+    terminator_idx :: usize(last_expr_token) + 1
+    tok_terminator :: if (terminator_idx < tokens.len) tokens[terminator_idx] else return
+    try arraylist.append(&renderer.tokens, tok_terminator)
+
+    eof_idx :: terminator_idx + 1
+    if (tok_terminator.kind == .newline and
+        eof_idx < tokens.len and
+        tokens[eof_idx].kind == .eof
+    ) try arraylist.append(&renderer.tokens, tokens[eof_idx])
+}
+
+render_expr proc(renderer @mut Renderer,
+    node_id NodeId,
+    parse_state @ParseState,
+    tokens []Token,
+) TokenId ! mem.AllocError {
+    # todo: support unary and binary expressions
+    node :: parse_state.nodes.items[usize(node_id)]
+    match node.kind {
+        .expr_identifier: {
+            tok :: tokens[usize(node.main_token)]
+            try arraylist.append(&renderer.tokens, tok)
+            return node.main_token
+        }
+        .literal_int, .literal_float, .literal_string:
+            return try render_lit(renderer, node_id, parse_state, tokens)
+        else: unreachable
+    }
+}
+
+render_type proc(
+    renderer @mut Renderer,
+    node_id NodeId,
+    parse_state @ParseState,
+    tokens []Token,
+) void ! mem.AllocError {
+    # todo: support more expressive type expressions...
+    node :: parse_state.nodes.items[usize(node_id)]
+    match node.kind {
+        .expr_identifier: {
+            tok :: tokens[usize(node.main_token)]
+            try arraylist.append(&renderer.tokens, tok)
+        }
+        else: unreachable
+    }
+}
+
+render_lit proc(
+    renderer @mut Renderer,
+    node_id NodeId,
+    parse_state @ParseState,
+    tokens []Token,
+) TokenId ! mem.AllocError {
+    node :: parse_state.nodes.items[usize(node_id)]
+    match node.kind {
+        .literal_int, .literal_float, .literal_string: {
+            tok :: tokens[node.main_token]
+            try arraylist.append(&renderer.tokens, tok)
+            return node.main_token
+        }
+        else: unreachable
+    }
+}