diff options
Diffstat (limited to 'vocabulary.md')
| -rw-r--r-- | vocabulary.md | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/vocabulary.md b/vocabulary.md index 60795226..f02b7fd3 100644 --- a/vocabulary.md +++ b/vocabulary.md @@ -38,8 +38,10 @@ how they work under the hood. By default, writes to a stream abort if it's full. Reads to a stream abort if it's empty. -- Graphemes: 32-bit fragments of utf-8 that encode a single Unicode code-point. -- Code-points: 32-bit integers representing a Unicode character. +- Graphemes: a sequence of up to 4 utf-8 bytes that encode a single Unicode + code-point. +- Code-points: integer representing a Unicode character. Must be representable + in 32 bits as utf-8; largest supported value is 0x10000. ### Functions @@ -114,8 +116,8 @@ signatures.mu for their full type signatures. - `append-byte-hex`: writes textual representation of lowest byte in hex to a stream of bytes. Does not write a '0x' prefix. - `read-byte`: reads a single byte from a stream of bytes. -- `read-grapheme`: reads a single unicode grapheme (up to 4 bytes containing a - single code-point encoded in utf-8) from a stream of bytes. +- `read-grapheme`: reads a single unicode grapheme (up to 4 bytes) from a + stream of bytes. #### reading/writing hex representations of integers @@ -141,14 +143,15 @@ All text-mode screen primitives require a screen object, which can be either the real screen on the computer or a fake screen for tests. The real screen on the Mu computer can currently display a subset of Unicode. -There is only one font, and it's mostly fixed-width, with graphemes being -either 8 or 16 pixels wide. - -- `draw-grapheme`: draws a single grapheme at a given coordinate, with given - foreground and background colors. -- `render-grapheme`: like `draw-grapheme` and can also handle newlines - assuming text is printed left-to-right, top-to-bottom. -- `draw-code-point` +There is only one font, and it's mostly fixed-width, with individual glyphs +for code-points being either 8 or 16 pixels wide. + +- `draw-code-point`: draws a single code-point at a given coordinate, with + given foreground and background colors. Returns the number of 8-pixel wide + grid locations used (either 1 or 2). +- `render-code-point`: like `draw-code-point`, but handles newlines and + updates cursor position. Assumes text is printed left-to-right, + top-to-bottom. - `clear-screen` - `draw-text-rightward`: draws a single line of text, stopping when it reaches @@ -176,12 +179,13 @@ Similar primitives for writing text top-to-bottom, left-to-right. - `draw-int32-decimal-wrapping-down-then-right` - `draw-int32-decimal-wrapping-down-then-right-over-full-screen` -Screens remember the current cursor position. +Screens remember the current cursor position. The following primitives +automatically read and update the cursor position in various ways. - `cursor-position` - `set-cursor-position` -- `draw-grapheme-at-cursor` -- `draw-code-point-at-cursor` +- `draw-code-point-at-cursor-over-full-screen`: `render-code-point` at + cursor position. - `draw-cursor`: highlights the current position of the cursor. Programs must pass in the grapheme to draw at the cursor position, and are responsible for clearing the highlight when the cursor moves. @@ -191,16 +195,21 @@ Screens remember the current cursor position. - `move-cursor-to-left-margin-of-next-line` - `move-cursor-rightward-and-downward`: move cursor one grapheme to the right -- `draw-text-rightward-from-cursor` -- `draw-text-wrapping-right-then-down-from-cursor` -- `draw-text-wrapping-right-then-down-from-cursor-over-full-screen` +- `draw-text-rightward-from-cursor`: truncate at some right margin. +- `draw-text-rightward-from-cursor-over-full-screen`: truncate at right edge + of screen. +- `draw-text-wrapping-right-then-down-from-cursor`: wrap at some right margin. +- `draw-text-wrapping-right-then-down-from-cursor-over-full-screen`: wrap at + right edge of screen. - `draw-int32-hex-wrapping-right-then-down-from-cursor` - `draw-int32-hex-wrapping-right-then-down-from-cursor-over-full-screen` - `draw-int32-decimal-wrapping-right-then-down-from-cursor` - `draw-int32-decimal-wrapping-right-then-down-from-cursor-over-full-screen` -- `draw-text-wrapping-down-then-right-from-cursor` -- `draw-text-wrapping-down-then-right-from-cursor-over-full-screen` +- `draw-text-wrapping-down-then-right-from-cursor`: wrap at some bottom + margin. +- `draw-text-wrapping-down-then-right-from-cursor-over-full-screen`: wrap at + bottom edge of screen. Assertions for tests: |