Commit 50c8a53188

Lachlan Easton <lachlan@lakebythewoods.xyz>
2020-08-30 02:32:21
Use ArrayList instead of fixed array for auto_indenting_stream
1 parent 7d95021
lib/std/io/auto_indenting_stream.zig
@@ -1,26 +1,36 @@
 const std = @import("../std.zig");
 const io = std.io;
 const mem = std.mem;
+const Allocator = mem.Allocator;
+const ArrayList = std.ArrayList;
 const assert = std.debug.assert;
 
 /// Automatically inserts indentation of written data by keeping
 /// track of the current indentation level
-pub fn AutoIndentingStream(comptime indent_delta: u8, comptime WriterType: type) type {
+pub fn AutoIndentingStream(comptime indent_delta: usize, comptime WriterType: type) type {
     return struct {
         const Self = @This();
         pub const Error = WriterType.Error;
+        pub const PushError = Allocator.Error;
         pub const Writer = io.Writer(*Self, Error, write);
+        const Stack = ArrayList(usize);
 
         writer_pointer: *WriterType,
+        indent_stack: Stack,
+
         current_line_empty: bool = true,
-        indent_stack: [255]u8 = undefined,
-        indent_stack_top: u8 = 0,
-        indent_one_shot_count: u8 = 0, // automatically popped when applied
-        applied_indent: u8 = 0, // the most recently applied indent
-        indent_next_line: u8 = 0, // not used until the next line
+        indent_one_shot_count: usize = 0, // automatically popped when applied
+        applied_indent: usize = 0, // the most recently applied indent
+        indent_next_line: usize = 0, // not used until the next line
+
+        pub fn init(writer_pointer: *WriterType, allocator: *Allocator) Self {
+            var indent_stack = Stack.init(allocator);
+            return Self{ .writer_pointer = writer_pointer, .indent_stack = indent_stack };
+        }
 
-        pub fn init(writer_pointer: *WriterType) Self {
-            return Self{ .writer_pointer = writer_pointer };
+        /// Release all allocated memory.
+        pub fn deinit(self: Self) void {
+            self.indent_stack.deinit();
         }
 
         pub fn writer(self: *Self) Writer {
@@ -39,7 +49,7 @@ pub fn AutoIndentingStream(comptime indent_delta: u8, comptime WriterType: type)
             if (bytes.len == 0)
                 return @as(usize, 0);
 
-            try self.writer_pointer.outStream().writeAll(bytes);
+            try self.writer_pointer.writer().writeAll(bytes);
             if (bytes[bytes.len - 1] == '\n')
                 self.resetLine();
             return bytes.len;
@@ -61,53 +71,52 @@ pub fn AutoIndentingStream(comptime indent_delta: u8, comptime WriterType: type)
         }
 
         /// Push default indentation
-        pub fn pushIndent(self: *Self) void {
-            // Doesn't actually write any indentation. Just primes the stream to be able to write the correct indentation if it needs to.
-            self.pushIndentN(indent_delta);
+        pub fn pushIndent(self: *Self) PushError!void {
+            // Doesn't actually write any indentation.
+            // Just primes the stream to be able to write the correct indentation if it needs to.
+            try self.pushIndentN(indent_delta);
         }
 
         /// Push an indent of arbitrary width
-        pub fn pushIndentN(self: *Self, n: u8) void {
-            assert(self.indent_stack_top < std.math.maxInt(u8));
-            self.indent_stack[self.indent_stack_top] = n;
-            self.indent_stack_top += 1;
+        pub fn pushIndentN(self: *Self, n: usize) PushError!void {
+            try self.indent_stack.append(n);
         }
 
         /// Push an indent that is automatically popped after being applied
-        pub fn pushIndentOneShot(self: *Self) void {
+        pub fn pushIndentOneShot(self: *Self) PushError!void {
             self.indent_one_shot_count += 1;
-            self.pushIndent();
+            try self.pushIndent();
         }
 
         /// Turns all one-shot indents into regular indents
         /// Returns number of indents that must now be manually popped
-        pub fn lockOneShotIndent(self: *Self) u8 {
+        pub fn lockOneShotIndent(self: *Self) usize {
             var locked_count = self.indent_one_shot_count;
             self.indent_one_shot_count = 0;
             return locked_count;
         }
 
         /// Push an indent that should not take effect until the next line
-        pub fn pushIndentNextLine(self: *Self) void {
+        pub fn pushIndentNextLine(self: *Self) PushError!void {
             self.indent_next_line += 1;
-            self.pushIndent();
+            try self.pushIndent();
         }
 
         pub fn popIndent(self: *Self) void {
-            assert(self.indent_stack_top != 0);
-            self.indent_stack_top -= 1;
-            self.indent_next_line = std.math.min(self.indent_stack_top, self.indent_next_line); // Tentative indent may have been popped before there was a newline
+            assert(self.indent_stack.items.len != 0);
+            self.indent_stack.items.len -= 1;
+            self.indent_next_line = std.math.min(self.indent_stack.items.len, self.indent_next_line); // Tentative indent may have been popped before there was a newline
         }
 
         /// Writes ' ' bytes if the current line is empty
         fn applyIndent(self: *Self) Error!void {
             const current_indent = self.currentIndent();
             if (self.current_line_empty and current_indent > 0) {
-                try self.writer_pointer.outStream().writeByteNTimes(' ', current_indent);
+                try self.writer_pointer.writer().writeByteNTimes(' ', current_indent);
                 self.applied_indent = current_indent;
             }
 
-            self.indent_stack_top -= self.indent_one_shot_count;
+            self.indent_stack.items.len -= self.indent_one_shot_count;
             self.indent_one_shot_count = 0;
             self.current_line_empty = false;
         }
@@ -118,11 +127,11 @@ pub fn AutoIndentingStream(comptime indent_delta: u8, comptime WriterType: type)
             return self.applied_indent > self.currentIndent();
         }
 
-        fn currentIndent(self: *Self) u8 {
-            var indent_current: u8 = 0;
-            if (self.indent_stack_top > 0) {
-                const stack_top = self.indent_stack_top - self.indent_next_line;
-                for (self.indent_stack[0..stack_top]) |indent| {
+        fn currentIndent(self: *Self) usize {
+            var indent_current: usize = 0;
+            if (self.indent_stack.items.len > 0) {
+                const stack_top = self.indent_stack.items.len - self.indent_next_line;
+                for (self.indent_stack.items[0..stack_top]) |indent| {
                     indent_current += indent;
                 }
             }
@@ -132,9 +141,10 @@ pub fn AutoIndentingStream(comptime indent_delta: u8, comptime WriterType: type)
 }
 
 pub fn autoIndentingStream(
-    comptime indent_delta: u8,
+    comptime indent_delta: usize,
     underlying_stream: anytype,
+    allocator: *Allocator,
 ) AutoIndentingStream(indent_delta, @TypeOf(underlying_stream).Child) {
     comptime assert(@typeInfo(@TypeOf(underlying_stream)) == .Pointer);
-    return AutoIndentingStream(indent_delta, @TypeOf(underlying_stream).Child).init(underlying_stream);
+    return AutoIndentingStream(indent_delta, @TypeOf(underlying_stream).Child).init(underlying_stream, allocator);
 }
lib/std/io/find_byte_out_stream.zig
@@ -8,7 +8,7 @@ pub fn FindByteOutStream(comptime WriterType: type) type {
     return struct {
         const Self = @This();
         pub const Error = WriterType.Error;
-        pub const OutStream = io.OutStream(*Self, Error, write);
+        pub const Writer = io.Writer(*Self, Error, write);
 
         writer_pointer: *WriterType,
         byte_found: bool,
@@ -22,7 +22,7 @@ pub fn FindByteOutStream(comptime WriterType: type) type {
             };
         }
 
-        pub fn outStream(self: *Self) OutStream {
+        pub fn writer(self: *Self) Writer {
             return .{ .context = self };
         }
 
lib/std/zig/render.zig
@@ -24,7 +24,8 @@ pub fn render(allocator: *mem.Allocator, stream: anytype, tree: *ast.Tree) (meta
 
     var s = stream.*;
     var change_detection_stream = std.io.changeDetectionStream(tree.source, &s);
-    var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, &change_detection_stream);
+    var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, &change_detection_stream, allocator);
+    defer auto_indenting_stream.deinit();
 
     try renderRoot(allocator, &auto_indenting_stream, tree);
 
@@ -388,11 +389,11 @@ fn renderExpression(
             }
 
             if (block.statements.len == 0) {
-                stream.pushIndentNextLine();
+                try stream.pushIndentNextLine();
                 defer stream.popIndent();
                 try renderToken(tree, stream, block.lbrace, Space.None);
             } else {
-                stream.pushIndentNextLine();
+                try stream.pushIndentNextLine();
                 defer stream.popIndent();
 
                 try renderToken(tree, stream, block.lbrace, Space.Newline);
@@ -462,7 +463,7 @@ fn renderExpression(
                 try renderExpression(allocator, stream, tree, payload, Space.Space);
             }
 
-            stream.pushIndentOneShot();
+            try stream.pushIndentOneShot();
             return renderExpression(allocator, stream, tree, infix_op_node.rhs, space);
         },
 
@@ -523,7 +524,7 @@ fn renderExpression(
             };
 
             try renderToken(tree, stream, infix_op_node.op_token, after_op_space);
-            stream.pushIndentOneShot();
+            try stream.pushIndentOneShot();
             return renderExpression(allocator, stream, tree, infix_op_node.rhs, space);
         },
 
@@ -717,7 +718,7 @@ fn renderExpression(
                 }
 
                 {
-                    stream.pushIndent();
+                    try stream.pushIndent();
                     defer stream.popIndent();
                     try renderToken(tree, stream, lbrace, Space.None);
                 }
@@ -782,7 +783,8 @@ fn renderExpression(
 
                 // Null stream for counting the printed length of each expression
                 var counting_stream = std.io.countingOutStream(std.io.null_out_stream);
-                var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, &counting_stream);
+                var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, &counting_stream, allocator);
+                defer auto_indenting_stream.deinit();
 
                 for (exprs) |expr, i| {
                     counting_stream.bytes_written = 0;
@@ -794,7 +796,7 @@ fn renderExpression(
                 }
 
                 {
-                    stream.pushIndentNextLine();
+                    try stream.pushIndentNextLine();
                     defer stream.popIndent();
                     try renderToken(tree, stream, lbrace, Space.Newline);
 
@@ -878,7 +880,7 @@ fn renderExpression(
                 }
 
                 {
-                    stream.pushIndentNextLine();
+                    try stream.pushIndentNextLine();
                     defer stream.popIndent();
                     try renderToken(tree, stream, lbrace, Space.None);
                 }
@@ -900,7 +902,8 @@ fn renderExpression(
                 // render field expressions until a LF is found
                 for (field_inits) |field_init| {
                     var find_stream = std.io.findByteOutStream('\n', &std.io.null_out_stream);
-                    var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, &find_stream);
+                    var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, &find_stream, allocator);
+                    defer auto_indenting_stream.deinit();
 
                     try renderExpression(allocator, &auto_indenting_stream, tree, field_init, Space.None);
                     if (find_stream.byte_found) break :blk false;
@@ -960,7 +963,7 @@ fn renderExpression(
                     .node => |node| try renderExpression(allocator, stream, tree, node, Space.None),
                 }
 
-                stream.pushIndentNextLine();
+                try stream.pushIndentNextLine();
                 defer stream.popIndent();
 
                 try renderToken(tree, stream, lbrace, Space.Newline);
@@ -1008,7 +1011,7 @@ fn renderExpression(
 
                 const params = call.params();
                 for (params) |param_node, i| {
-                    stream.pushIndent();
+                    try stream.pushIndent();
                     defer stream.popIndent();
 
                     if (i + 1 < params.len) {
@@ -1028,7 +1031,7 @@ fn renderExpression(
 
             const params = call.params();
             for (params) |param_node, i| {
-                if (param_node.*.tag == .MultilineStringLiteral) stream.pushIndentOneShot();
+                if (param_node.*.tag == .MultilineStringLiteral) try stream.pushIndentOneShot();
 
                 try renderExpression(allocator, stream, tree, param_node, Space.None);
 
@@ -1055,7 +1058,7 @@ fn renderExpression(
             {
                 const new_space = if (ends_with_comment) Space.Newline else Space.None;
 
-                stream.pushIndent();
+                try stream.pushIndent();
                 defer stream.popIndent();
                 try renderExpression(allocator, stream, tree, suffix_op.index_expr, new_space);
             }
@@ -1191,7 +1194,7 @@ fn renderExpression(
 
             try renderToken(tree, stream, grouped_expr.lparen, Space.None);
             {
-                stream.pushIndentOneShot();
+                try stream.pushIndentOneShot();
                 try renderExpression(allocator, stream, tree, grouped_expr.expr, Space.None);
             }
             return renderToken(tree, stream, grouped_expr.rparen, space);
@@ -1251,7 +1254,7 @@ fn renderExpression(
 
             if (container_decl.fields_and_decls_len == 0) {
                 {
-                    stream.pushIndentNextLine();
+                    try stream.pushIndentNextLine();
                     defer stream.popIndent();
                     try renderToken(tree, stream, container_decl.lbrace_token, Space.None); // {
                 }
@@ -1286,7 +1289,7 @@ fn renderExpression(
 
             if (src_has_trailing_comma or !src_has_only_fields) {
                 // One declaration per line
-                stream.pushIndentNextLine();
+                try stream.pushIndentNextLine();
                 defer stream.popIndent();
                 try renderToken(tree, stream, container_decl.lbrace_token, .Newline); // {
 
@@ -1302,7 +1305,7 @@ fn renderExpression(
                 // their own line
                 try renderToken(tree, stream, container_decl.lbrace_token, .Newline); // {
 
-                stream.pushIndent();
+                try stream.pushIndent();
                 defer stream.popIndent();
 
                 for (fields_and_decls) |decl, i| {
@@ -1358,7 +1361,7 @@ fn renderExpression(
 
             if (src_has_trailing_comma) {
                 {
-                    stream.pushIndent();
+                    try stream.pushIndent();
                     defer stream.popIndent();
 
                     try renderToken(tree, stream, lbrace, Space.Newline); // {
@@ -1448,7 +1451,7 @@ fn renderExpression(
                 }
             } else {
                 // one param per line
-                stream.pushIndent();
+                try stream.pushIndent();
                 defer stream.popIndent();
                 try renderToken(tree, stream, lparen, Space.Newline); // (
 
@@ -1527,7 +1530,7 @@ fn renderExpression(
                 }
             } else {
                 // one param per line
-                stream.pushIndent();
+                try stream.pushIndent();
                 defer stream.popIndent();
                 try renderToken(tree, stream, lparen, Space.Newline); // (
 
@@ -1624,7 +1627,7 @@ fn renderExpression(
             try renderToken(tree, stream, rparen, Space.Space); // )
 
             {
-                stream.pushIndentNextLine();
+                try stream.pushIndentNextLine();
                 defer stream.popIndent();
                 try renderToken(tree, stream, lbrace, Space.Newline); // {
 
@@ -1708,7 +1711,7 @@ fn renderExpression(
             if (same_line) {
                 return renderExpression(allocator, stream, tree, else_node.body, space);
             } else {
-                stream.pushIndent();
+                try stream.pushIndent();
                 defer stream.popIndent();
                 return renderExpression(allocator, stream, tree, else_node.body, space);
             }
@@ -1772,7 +1775,7 @@ fn renderExpression(
             }
 
             {
-                if (!body_is_block) stream.pushIndent();
+                if (!body_is_block) try stream.pushIndent();
                 defer if (!body_is_block) stream.popIndent();
                 try renderExpression(allocator, stream, tree, while_node.body, after_body_space);
             }
@@ -1823,7 +1826,7 @@ fn renderExpression(
             };
 
             {
-                if (!body_on_same_line) stream.pushIndent();
+                if (!body_on_same_line) try stream.pushIndent();
                 defer if (!body_on_same_line) stream.popIndent();
                 try renderExpression(allocator, stream, tree, for_node.body, space_after_body); // { body }
             }
@@ -1879,7 +1882,7 @@ fn renderExpression(
                     const else_is_block = nodeIsBlock(@"else".body);
 
                     {
-                        stream.pushIndent();
+                        try stream.pushIndent();
                         defer stream.popIndent();
                         try renderExpression(allocator, stream, tree, if_node.body, Space.Newline);
                     }
@@ -1900,12 +1903,12 @@ fn renderExpression(
                             try renderExpression(allocator, stream, tree, payload, Space.Newline);
                         }
 
-                        stream.pushIndent();
+                        try stream.pushIndent();
                         defer stream.popIndent();
                         return renderExpression(allocator, stream, tree, @"else".body, space);
                     }
                 } else {
-                    stream.pushIndent();
+                    try stream.pushIndent();
                     defer stream.popIndent();
                     return renderExpression(allocator, stream, tree, if_node.body, space);
                 }
@@ -1946,7 +1949,7 @@ fn renderExpression(
             }
 
             asmblk: {
-                stream.pushIndent();
+                try stream.pushIndent();
                 defer stream.popIndent();
 
                 if (asm_node.outputs.len == 0 and asm_node.inputs.len == 0 and asm_node.clobbers.len == 0) {
@@ -1965,7 +1968,7 @@ fn renderExpression(
                 } else blk: {
                     try renderToken(tree, stream, colon1, Space.Space); // :
 
-                    stream.pushIndentN(2);
+                    try stream.pushIndentN(2);
                     defer stream.popIndent();
 
                     for (asm_node.outputs) |*asm_output, i| {
@@ -1996,7 +1999,7 @@ fn renderExpression(
                     break :blk tree.nextToken(colon2);
                 } else blk: {
                     try renderToken(tree, stream, colon2, Space.Space); // :
-                    stream.pushIndentN(2);
+                    try stream.pushIndentN(2);
                     defer stream.popIndent();
                     for (asm_node.inputs) |*asm_input, i| {
                         if (i + 1 < asm_node.inputs.len) {
@@ -2022,7 +2025,7 @@ fn renderExpression(
                 };
 
                 try renderToken(tree, stream, colon3, Space.Space); // :
-                stream.pushIndentN(2);
+                try stream.pushIndentN(2);
                 defer stream.popIndent();
                 for (asm_node.clobbers) |clobber_node, i| {
                     if (i + 1 >= asm_node.clobbers.len) {
@@ -2075,7 +2078,7 @@ fn renderArrayType(
     const new_space = if (ends_with_comment) Space.Newline else Space.None;
     {
         const do_indent = (starts_with_comment or ends_with_comment);
-        if (do_indent) stream.pushIndent();
+        if (do_indent) try stream.pushIndent();
         defer if (do_indent) stream.popIndent();
 
         try renderToken(tree, stream, lbracket, Space.None); // [
@@ -2209,7 +2212,7 @@ fn renderVarDecl(
     if (var_decl.getTrailer("init_node")) |init_node| {
         const s = if (init_node.tag == .MultilineStringLiteral) Space.None else Space.Space;
         try renderToken(tree, stream, var_decl.getTrailer("eq_token").?, s); // =
-        stream.pushIndentOneShot();
+        try stream.pushIndentOneShot();
         try renderExpression(allocator, stream, tree, init_node, Space.None);
     }