add runPrompt / runFile / run functions

src/main.zig

@@ -1,5 +1,78 @@
 const std = @import("std");
 
-pub fn main() anyerror!void {
-    std.debug.warn("All your base are belong to us.\n");
+const Allocator = std.mem.Allocator;
+
+pub const Result = error{
+    Ok,
+    CompileError,
+};
+
+fn run(allocator: *Allocator, data: []u8) !void {
+    var stdout_file = try std.io.getStdOut();
+    const stdout = &stdout_file.outStream().stream;
+    return Result.Ok;
+}
+
+fn runFile(allocator: *Allocator, path: []const u8) !void {
+    var file = try std.fs.File.openRead(path);
+    defer file.close();
+
+    const total_bytes = try file.getEndPos();
+
+    var slice = try allocator.alloc(u8, total_bytes);
+    _ = try file.read(slice);
+
+    run(allocator, slice) catch |err| {
+        switch (err) {
+            Result.Ok => {},
+            Result.CompileError => std.os.exit(65),
+            else => return err,
+        }
+    };
+}
+
+fn runPrompt(allocator: *Allocator) !void {
+    var stdout_file = try std.io.getStdOut();
+    const stdout = &stdout_file.outStream().stream;
+
+    while (true) {
+        try stdout.print("> ");
+        var buffer = try std.Buffer.init(allocator, ""[0..]);
+
+        var line = std.io.readLine(&buffer) catch |err| {
+            if (err == error.EndOfStream) return;
+            return err;
+        };
+
+        run(allocator, line) catch |err| {
+            switch (err) {
+                Result.Ok => {},
+                Result.CompileError => blk: {
+                    try stdout.print("compile error.\n");
+                },
+                else => return err,
+            }
+        };
+    }
+}
+
+pub fn main() anyerror!void {
+    var da = std.heap.DirectAllocator.init();
+    var arena = std.heap.ArenaAllocator.init(&da.allocator);
+    defer arena.deinit();
+    var allocator = &arena.allocator;
+
+    var stdout_file = try std.io.getStdOut();
+    var stdout = &stdout_file.outStream().stream;
+
+    var args_it = std.process.args();
+
+    _ = args_it.next(allocator);
+
+    var filePath = try (args_it.next(allocator) orelse {
+        try runPrompt(allocator);
+        return;
+    });
+
+    try runFile(allocator, filePath);
 }

src/scanner.zig

@@ -0,0 +1,31 @@
+const std = @import("std");
+const tokens = @import("tokens.std");
+
+const Allocator = std.mem.Allocator;
+
+pub const TokenError = error{
+    Unexpected,
+    Unterminated,
+};
+
+fn isDigit(char: u8) bool {
+    return char >= '0' and char <= '9';
+}
+
+fn isAlpha(c: u8) bool {
+    return (c >= 'a' and c <= 'z') or
+        (c >= 'A' and c <= 'Z') or
+        c == '_';
+}
+
+fn isAlphaNumeric(char: u8) bool {
+    return isAlpha(char) or isDigit(char);
+}
+
+pub const Scanner = struct {
+    allocator: *Allocator,
+
+    pub fn init(allocator: *Allocator) Scanner {
+        return Scanner{ .allocator = allocator };
+    }
+};

src/tokens.zig

@@ -0,0 +1,73 @@
+pub const TokenType = enum {
+    // basic tokens
+    LeftParen,
+    RightParen,
+    LeftBrace,
+    RightBrace,
+    LeftSquare,
+    RightSquare,
+    Dot,
+    Equal,
+    Semicolon,
+    Comma,
+    Colon,
+    Ampersand,
+    Pipe,
+    QuestionMark,
+    DollarSign,
+
+    // math operators
+    Plus,
+    Minus,
+    Star,
+    Slash,
+    Modulo,
+
+    // one-two char tokens
+    DotEqual,
+    LeftDoubleChevron, // AKA "<<"
+    PlusPlus,
+    PlusEqual,
+    MinusEqual,
+
+    LessThan,
+    LessEqual,
+    GreaterThan,
+    GreaterEqual,
+    Bang,
+    BangEqual,
+
+    // complex types
+    Integer,
+    Float,
+    String,
+    Identifier,
+
+    // keywords
+    Break,
+    Const,
+    Continue,
+    Defer,
+    Else,
+    Enum,
+    Fn,
+    For,
+    Go,
+    Goto,
+    If,
+    Import,
+    In,
+    Interface,
+    Match,
+    Module,
+    Mut,
+    Or,
+    Return,
+    Struct,
+    Type,
+};
+
+pub const Token = struct {
+    ttype: TokenType,
+    lexeme: []u8,
+};