feat: add error handling to string lexing

src/01_lexic/root.zig

@@ -41,8 +41,9 @@ pub fn tokenize(
             break;
         }
 
-        // attempt to lex a number
         var current_error: errors.ErrorData = undefined;
+
+        // attempt to lex a number
         const number_lex = number.lex(input, input_len, actual_next_pos, &current_error, alloc) catch |e| switch (e) {
             // recoverable errors
             LexError.Incomplete, LexError.LeadingZero, LexError.IncompleteFloatingNumber, LexError.IncompleteScientificNumber => {
@@ -51,7 +52,6 @@ pub fn tokenize(
 
                 // ignore everything until whitespace and loop
                 current_pos = ignore_until_whitespace(input, actual_next_pos);
-                assert(current_pos > actual_next_pos);
                 continue;
             },
             // just throw unrecoverable errors
@@ -66,24 +66,36 @@ pub fn tokenize(
             continue;
         }
 
-        // attempt to lex an identifier
+        // attempt to lex an identifier. identifier parsing has no errors
-        else if (try identifier.lex(input, actual_next_pos)) |tuple| {
+        if (try identifier.lex(input, actual_next_pos)) |tuple| {
             assert(tuple[1] > current_pos);
             const t = tuple[0];
             current_pos = tuple[1];
 
             try tokens.append(t);
+            continue;
         }
+
         // attempt to lex a string
-        else if (try string.lex(input, actual_next_pos)) |tuple| {
+        const str_lex = string.lex(input, actual_next_pos, &current_error, alloc) catch |e| switch (e) {
+            LexError.IncompleteString => {
+                try err_arrl.append(current_error);
+                current_pos = ignore_until_whitespace(input, actual_next_pos);
+                continue;
+            },
+            else => return e,
+        };
+        if (str_lex) |tuple| {
             assert(tuple[1] > current_pos);
             const t = tuple[0];
             current_pos = tuple[1];
 
             try tokens.append(t);
+            continue;
         }
+
         // attempt to lex a datatype
-        else if (try datatype.lex(input, actual_next_pos)) |tuple| {
+        if (try datatype.lex(input, actual_next_pos)) |tuple| {
             assert(tuple[1] > current_pos);
             const t = tuple[0];
             current_pos = tuple[1];
@@ -190,17 +202,17 @@ test "should insert an item, fail, and not leak" {
     const input = "322 \"hello";
     var error_list = std.ArrayList(errors.ErrorData).init(std.testing.allocator);
     defer error_list.deinit();
+    defer for (error_list.items) |*i| {
+        i.deinit();
+    };
+
     const arrl = tokenize(input, std.testing.allocator, &error_list) catch |e| switch (e) {
-        error.IncompleteString => {
-            return;
-        },
         else => {
             try std.testing.expect(false);
             return;
         },
     };
-    try std.testing.expect(false);
+    defer arrl.deinit();
-    arrl.deinit();
 }
 
 test "shouldnt leak" {

src/01_lexic/string.zig

@@ -2,13 +2,19 @@ const std = @import("std");
 const assert = std.debug.assert;
 const token = @import("./token.zig");
 const utils = @import("./utils.zig");
+const errors = @import("errors");
 
 const Token = token.Token;
 const TokenType = token.TokenType;
 const LexError = token.LexError;
 const LexReturn = token.LexReturn;
 
-pub fn lex(input: []const u8, start: usize) LexError!?LexReturn {
+pub fn lex(
+    input: []const u8,
+    start: usize,
+    err: *errors.ErrorData,
+    alloc: std.mem.Allocator,
+) LexError!?LexReturn {
     const cap = input.len;
     assert(start < cap);
 
@@ -28,18 +34,28 @@ pub fn lex(input: []const u8, start: usize) LexError!?LexReturn {
                 current_pos + 1,
             };
         }
-        // new line, return error
+        // new line, initialize and return error
         else if (next_char == '\n') {
+            try err.init("Incomplete String", current_pos, current_pos + 1, alloc);
+            try err.add_label("Found a new line here", current_pos, current_pos + 1);
+            err.set_help("Strings must always end on the same line that they start.");
+
             return LexError.IncompleteString;
         }
         // lex escape characters
         else if (next_char == '\\') {
             // if next char is EOF, return error
             if (current_pos + 1 == cap) {
+                try err.init("Incomplete String", current_pos, current_pos + 1, alloc);
+                try err.add_label("Found EOF here", current_pos, current_pos + 1);
+                err.set_help("Strings must always end on the same line that they start.");
                 return LexError.IncompleteString;
             }
             // if next char is newline, return error
             else if (input[current_pos + 1] == '\n') {
+                try err.init("Incomplete String", current_pos, current_pos + 1, alloc);
+                try err.add_label("Found a new line here", current_pos, current_pos + 1);
+                err.set_help("Strings must always end on the same line that they start.");
                 return LexError.IncompleteString;
             }
             // here just consume whatever char is after
@@ -52,12 +68,16 @@ pub fn lex(input: []const u8, start: usize) LexError!?LexReturn {
     }
 
     // this could only reach when EOF is hit, return error
+    try err.init("Incomplete String", current_pos, current_pos + 1, alloc);
+    try err.add_label("Found EOF here", current_pos, current_pos + 1);
+    err.set_help("Strings must always end on the same line that they start.");
+
     return LexError.IncompleteString;
 }
 
 test "should lex empty string" {
     const input = "\"\"";
-    const output = try lex(input, 0);
+    const output = try lex(input, 0, undefined, std.testing.allocator);
 
     if (output) |tuple| {
         const t = tuple[0];
@@ -70,7 +90,7 @@ test "should lex empty string" {
 
 test "should lex string with 1 char" {
     const input = "\"a\"";
-    const output = try lex(input, 0);
+    const output = try lex(input, 0, undefined, std.testing.allocator);
 
     if (output) |tuple| {
         const t = tuple[0];
@@ -83,7 +103,7 @@ test "should lex string with 1 char" {
 
 test "should lex string with unicode" {
     const input = "\"😭\"";
-    const output = try lex(input, 0);
+    const output = try lex(input, 0, undefined, std.testing.allocator);
 
     if (output) |tuple| {
         const t = tuple[0];
@@ -96,14 +116,16 @@ test "should lex string with unicode" {
 
 test "shouldnt lex other things" {
     const input = "322";
-    const output = try lex(input, 0);
+    const output = try lex(input, 0, undefined, std.testing.allocator);
     try std.testing.expect(output == null);
 }
 
 test "should fail on EOF before closing string" {
     const input = "\"hello";
-    _ = lex(input, 0) catch |err| {
+    var errdata: errors.ErrorData = undefined;
+    _ = lex(input, 0, &errdata, std.testing.allocator) catch |err| {
         try std.testing.expectEqual(LexError.IncompleteString, err);
+        defer errdata.deinit();
         return;
     };
 
@@ -112,8 +134,10 @@ test "should fail on EOF before closing string" {
 
 test "should fail on newline before closing string" {
     const input = "\"hello\n";
-    _ = lex(input, 0) catch |err| {
+    var errdata: errors.ErrorData = undefined;
+    _ = lex(input, 0, &errdata, std.testing.allocator) catch |err| {
         try std.testing.expectEqual(LexError.IncompleteString, err);
+        defer errdata.deinit();
         return;
     };
 
@@ -122,7 +146,7 @@ test "should fail on newline before closing string" {
 
 test "should lex string with escape character 1" {
     const input = "\"test\\\"string\"";
-    const output = try lex(input, 0);
+    const output = try lex(input, 0, undefined, std.testing.allocator);
 
     if (output) |tuple| {
         const t = tuple[0];
@@ -135,7 +159,7 @@ test "should lex string with escape character 1" {
 
 test "should lex string with escape character 2" {
     const input = "\"test\\\\string\"";
-    const output = try lex(input, 0);
+    const output = try lex(input, 0, undefined, std.testing.allocator);
 
     if (output) |tuple| {
         const t = tuple[0];
@@ -148,7 +172,9 @@ test "should lex string with escape character 2" {
 
 test "should fail on EOF after backslash" {
     const input = "\"hello \\";
-    _ = lex(input, 0) catch |err| {
+    var errdata: errors.ErrorData = undefined;
+    _ = lex(input, 0, &errdata, std.testing.allocator) catch |err| {
+        defer errdata.deinit();
         try std.testing.expectEqual(LexError.IncompleteString, err);
         return;
     };
@@ -158,7 +184,9 @@ test "should fail on EOF after backslash" {
 
 test "should fail on newline after backslash" {
     const input = "\"hello \\\n";
-    _ = lex(input, 0) catch |err| {
+    var errdata: errors.ErrorData = undefined;
+    _ = lex(input, 0, &errdata, std.testing.allocator) catch |err| {
+        defer errdata.deinit();
         try std.testing.expectEqual(LexError.IncompleteString, err);
         return;
     };