Crate codemap

A data structure for tracking source positions in language implementations, inspired by the CodeMap type in rustc’s libsyntax.

The CodeMap tracks all source files and maps positions within them to linear indexes as if all source files were concatenated. This allows a source position to be represented by a small 32-bit Pos indexing into the CodeMap, under the assumption that the total amount of parsed source code will not exceed 4GiB. The CodeMap can look up the source file, line, and column of a Pos or Span, as well as provide source code snippets for error reporting.

Example

use codemap::CodeMap;
let mut codemap = CodeMap::new();
let file = codemap.add_file("test.rs".to_string(), "fn test(){\n    println!(\"Hello\");\n}\n".to_string());
let string_literal_span = file.span.subspan(24, 31);

let location = codemap.look_up_span(string_literal_span);
assert_eq!(location.file.name(), "test.rs");
assert_eq!(location.begin.line, 1);
assert_eq!(location.begin.column, 13);
assert_eq!(location.end.line, 1);
assert_eq!(location.end.column, 20);

Structs

• CodeMap
  A data structure recording source code files for position lookup.
• File
  A CodeMap’s record of a source file.
• LineCol
  A line and column.
• Loc
  A file, and a line and column within it.
• Pos
  A small, Copy, value representing a position in a CodeMap’s file.
• Span
  A range of text within a CodeMap.
• SpanLoc
  A file, and a line and column range within it.
• Spanned
  Associate a Span with a value of arbitrary type (e.g. an AST node).